#⚛️┃physics | Official Unity Discord | Page 40

coral mango Sep 8, 2019, 3:16 AM

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@lime iron I noticed that the ragdoll is still disabled when you add the force, that might be causing some problem?

strange raven Sep 8, 2019, 4:00 AM

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@coral mango He is applying force to the main RB, which is always enabled, not any of the children

coral mango Sep 8, 2019, 4:05 AM

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Yeah, but until ragdoll is enabled it is still controlled by the animator, right?

lime iron Sep 8, 2019, 7:14 AM

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@coral mango I tried it both ways (before and after) but both didint work

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@strange raven ill try that, thanks

coral mango Sep 8, 2019, 7:20 AM

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https://i.imgur.com/PU7f37D.mp4 Totally normal physics

Imgur

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https://i.imgur.com/w7asNzM.mp4 Nothing to see here

Imgur

lime iron Sep 8, 2019, 7:57 AM

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@strange raven I tried it, The ragdoll now floats in the air but its still not moving up. The parent object though, is moving up

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So i guess the childs just dont move with the parent

sly violet Sep 8, 2019, 9:45 AM

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@lime iron : So i guess the childs just dont move with the parent
Correct; rigidbodies do not, as a general rule, move with their parent. The physics calculations override the effects of the parent transform.
I'm guessing what we're seeing in your video is that the ragdoll ignores the parent while it's actively ragdolling and then follows the parent when it settles down and its components go into "Sleep" mode.

lime iron Sep 8, 2019, 9:46 AM

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ohh

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Is there any way to make the ragdoll fly away from for example an explosion

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while still ragdolling

sly violet Sep 8, 2019, 9:47 AM

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Typically you just use AddForce for that sort of thing. There's even an AddExplosionForce method in Rigidbody you can use.

lime iron Sep 8, 2019, 9:48 AM

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Yes but as shown before that does not work with ragdolls 😛

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at least

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Not by applying it to the parent

sly violet Sep 8, 2019, 9:49 AM

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Yeah, you need to apply it to one or more of the rigidbodies comprising the ragdoll, not the parent.

lime iron Sep 8, 2019, 9:54 AM

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That worked 😄

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Thanks @sly violet

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1 more hting

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Someone stated above that disabling gravity is necessary for the force to work on the ragdoll, but is it possible to still have some kind of gravity?

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When i keep the gravity enabled, the ragdoll just falls to the ground without any force

sly violet Sep 8, 2019, 10:02 AM

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Hmm. Apparently you're supposed to keep gravity off until you go into ragdoll mode, and then turn it on. Otherwise the effects of gravity accumulate until they're super strong and override anything else that gets applied. At least, that's what some people are saying, I don't have experience with that personally.

lime iron Sep 8, 2019, 10:12 AM

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Okay

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so

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now gravity is off until i click on the model and it applies a force to the part of the model i clicked at

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but the force doesn't work until i click a second time 😮

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oh wait

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im dumb i think

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I disable the collider from the ragdoll but im still trying to raycast it -_-

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@sly violet Got it working by adding the Ignore Raycast layer to the parent collider

zinc furnace Sep 8, 2019, 10:41 AM

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Anyone able to help me figure out the best math calculation to use?

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I need to take a force which is applied to an object and split it into a tangential component, and a non-tangential component

sly violet Sep 8, 2019, 5:12 PM

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@zinc furnace : You'll need the "normal" of the plane you want to be tangential to. Once you've got that, you can use "ProjectOnPlane" to get the component of your force vector that's tangential to the plane, and then you can just subtract that from the force vector to get the rest of it.

zinc furnace Sep 8, 2019, 6:13 PM

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the short answer is apprrently F - R(F.R) where F is the force vector and R is a vector describing the direction between the point of contact and the centre of gravity.

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thanks @sly violet

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Oh, and F.R is dot product

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(R is the normal of the plane, in this case.)

sterile flicker Sep 8, 2019, 7:30 PM

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Hey guys I might need a bit of help I have this character that is suppose to collide against some scene elements, when it's collide with it he is suppose to bounce back and the scene elements get destroy but sometimes the character would just go right through it and destroying the element without bouncing, since I handle all the element destroy things in OnCollisionEnter is that the problem ? and how should I go around that pls ?

sly violet Sep 8, 2019, 9:27 PM

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@sterile flicker : It's a good practice to never destroy/deactivate a collider during an Event. (Mostly because the order in which Events methods are called for a single event is arbitrary and may cause inconsistent behavior.) Just set a flag and destroy it in FixedUpdate instead.

private bool destroyMe = false;

void OnCollisionEnter(Collider other) {
    destroyMe = true;
}

void FixedUpdate() {
    if (destroyMe) Destroy(gameObject);
}```

sterile flicker Sep 8, 2019, 9:28 PM

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OK thanks a lot

torpid prism Sep 9, 2019, 10:19 AM

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How do i move an object forward based on its rotation ? I got a capsule and its rotated on the X axis, i want to move its local position based on the Y position, similar to how you would use the unity in editor arrows but when local transform is enabled so the drag arrows will also rotate on the X axis

dawn venture Sep 9, 2019, 10:27 AM

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If it's to move them through scripting, each object transform has a forward, right, and up variable which is local to that object. so to move the object through script you can use x.transform.up

torpid prism Sep 9, 2019, 10:27 AM

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i tried transform.up but its using the global rotation

dawn venture Sep 9, 2019, 10:32 AM

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if it's just transform.up that's the global one, it's essentially the same as Vector3.up. refer to the gameobject transform first

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so if your gameobject was declared as g it would require g.transform.up

torpid prism Sep 9, 2019, 10:33 AM

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but in my case its the same object, basically i want to know how to rotate a vector based on local rotation

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ok nvm i figure it out

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didn't know it was possible to multiple quaternion with a vector3

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this is what i got:

transform.localPosition = transform.localRotation * new Vector3( 0, startDistance, 0 );

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@dawn venture thanks anyway

dawn venture Sep 9, 2019, 10:37 AM

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np, thought you were trying to move rather than rotate

torpid prism Sep 9, 2019, 10:37 AM

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but i am moving

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similar to how the in editor arrows move the object

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📎 unknown.png

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in "local" mode

dawn venture Sep 9, 2019, 10:45 AM

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ahhh, get you now.

prisma surge Sep 9, 2019, 10:52 AM

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I'm trying to debug a problem in our game where we occasionally get large lag spikes - The lag spikes seem to be caused by something running in FixedUpdate, but it looks like FixedUpdate is getting called like 7 times at once causing a freeze

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is this caused by the FixedUpdate lasting longer than the physics timestep?

torpid prism Sep 9, 2019, 10:54 AM

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what is your default solver iterations value ?

prisma surge Sep 9, 2019, 10:54 AM

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6

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physics timestep is at 0.02

torpid prism Sep 9, 2019, 10:55 AM

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Have you used the profiler* to see what might be causing it ?

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There is also the Physics Debugger

prisma surge Sep 9, 2019, 10:57 AM

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ive been profiling it and ive found a method thats doing something kinda slow, but the thing that is confusing me is that instead of it being called in one FixedUpdate when i look at it, i see like 7 FixedUpdate calls

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erm i looked at the physics part in the profiler and the physics part where it lists stuff like collision counts, it shows normal values

torpid prism Sep 9, 2019, 11:00 AM

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Correct me if im wrong but the fixed update function will be called multiple times per single frame based on how the event in unity works, should be normal. In regarding what causing the spike it might be the actual code inside the fixed update that needs to be optimized

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could it be the case that the lag spike will cause the FixedUpdate to be called exactly 7 times , but when there is no lag there are less calls of the same function ?

prisma surge Sep 9, 2019, 12:27 PM

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@torpid prism looking at it further there doesnt seem to be one specific thing thats actually causing it

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do you think that just having too much shit in fixedupdate can cause the execution time of the fixed update to exceed the actual physics timestep time, so the engine has to run several frames in a row

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so its kind of like a feedback loop in a sense

torpid prism Sep 9, 2019, 1:00 PM

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@prisma surge I wouldn't know

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I would try and isolate the code that might cause the lag / freeze and see if it is what actually causing it.

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If so optimizing would be my first choice, besides that I can't help without seeing the actual code

prisma surge Sep 9, 2019, 1:02 PM

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im trying to isolate it by just straight up disabling things but something always takes its place

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yeah im pretty convinced its more about the fact that theres so much stuff being done in fixedupdate

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i doubled the rate of the timestep and it started lagging like shit, halved it and now it doesnt seem to be spiking like that

ocean horizon Sep 9, 2019, 1:30 PM

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If you're spending too much time so that fixed-update is being called multiple times then increasing the frequency of the timestep will just mean it'll be called more times.

torpid prism Sep 9, 2019, 1:32 PM

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@ocean horizon is the time step is 1 : 1 ratio ? ( when using 0.02 will it result in 20 updates per second ? )

ocean horizon Sep 9, 2019, 1:35 PM

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The time-step is specified in seconds so it's 1 / timestep so 0.02 = 1 / 0.02 = 50

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On average the frequency will be this but in reality it just means it'll try to ensure that 50 calls per second happen. You can see the pseudo code for what happens here in the code example: https://docs.unity3d.com/ScriptReference/Physics.Simulate.html

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So for instance, if the time elapsed from the previous fixed-update cycle is twice the fixed-update time then it'll be called twice. This might happen if the frame-rendering took a long time or scripts in Update callbacks did the same.

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It can lead to a spiral of doom though where the system is taking too long so it runs multiple fixed-update which in turn takes a long time and you can get a negative feedback loop. If not death, it can lead to severe hiccups.

sly violet Sep 9, 2019, 1:41 PM

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Yeah, getting multiple FixedUpdates per frame might be caused by something in FixedUpdate, but it can also be caused by something that's not in FixedUpdate at all.

ocean horizon Sep 9, 2019, 1:42 PM

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Also, the choice of 50hz for the default in Unity is kind of bonkers. It should be a more sensible 60hz or an approximation of it. 50Hz is pretty much going to cause aliasing of fixed-update/update.

torpid prism Sep 9, 2019, 1:43 PM

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do you mean rendering aliasing ?

lapis plaza Sep 9, 2019, 1:44 PM

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yeah, I agree it's a silly default

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it pretty much guarantees that your physics will always jitter whatever you do if you don't use interpolation or extrapolation

torpid prism Sep 9, 2019, 1:45 PM

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would it be recommended to match the game fps then ?

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for example a vr game running at 90/80 Hz

lapis plaza Sep 9, 2019, 1:45 PM

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that makes physics sim less predictable

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but if you don't care about determinism and can vsync, it's not that bad

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in general, more physics steps you do, less such impact this has

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in VR the responsiveness is key

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so that's a good argument on running physics steps on regular update for it when you can guarantee 90fps or more

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running physics at 90Hz is more taxing on physics heavy scenes than running it with 60Hz but you don't have to do interpolation for smooth movement so you win little back there

torpid prism Sep 9, 2019, 1:49 PM

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what about something like networked VR game at 90fps, would 50Hz will be enough ?

lapis plaza Sep 9, 2019, 1:49 PM

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networked physics is going to be super difficult always

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unless you just do it on client side and workaround the edge cases

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but what I meant before was that you could just tie the physics steps to rendering update speed in VR apps

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like, literally call physics.simulate manually on update once if >90Hz and twice if you drop below etc

ocean horizon Sep 9, 2019, 1:51 PM

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One thing to consider that the most probable reason why 50hz was chosen wasn't based upon any prevalence of 50hz monitors back in the day but more that 1/50 gives a nice value whereas 1/60 doesn't. Yep, it was probably that weak of a reason so best thing is to not consider 50hz special because it's the default but consider what the lowest frequency you can get away with in your particular physics simulation so you're not spending too much time simulating physics that you could spend on other more useful stuff.

torpid prism Sep 9, 2019, 1:52 PM

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@lapis plaza sorry to bug you but

>90
did you mean if the update is greater then 90Hz or less then 90 ?

lapis plaza Sep 9, 2019, 1:53 PM

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oh I meant that if you can guarantee you can render at target refresh rate

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be it 90, 120 Hz or whatever that specific VR headset supports

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basically in such case, you could do basic substepping setup which would add more physics steps if the max deltatime for physics would grow too big but otherwise just use the VR refresh rate

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this is pretty much how UE4's physics substepping works out of the box (they don't even have fixed timesteps there on stock engine)

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for VR, this is great as you get as responsive physics as possible

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for most other physics simulations, you'd prefer fixed timesepped updates for physics as it's just more robust in general, less surprises on the results and more similar simulation conditions for all

prisma surge Sep 9, 2019, 1:56 PM

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the reason i lowered the timestep is because if this code is doing too much stuff in fixed update, then it will probably be calling fixed update even more because it will be so far behind

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and doubling it should show that the code has enough time to execute within each step

torpid prism Sep 9, 2019, 1:56 PM

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@lapis plaza i see, thank you for the info

prisma surge Sep 9, 2019, 1:56 PM

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and it seemed to fix it, so i think we just need to remove a bunch of shit

lapis plaza Sep 9, 2019, 1:57 PM

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in any case, I'd always make prototypes and test on your actual target use case

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theory is one thing, and other is making it work like you want

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sometimes the less ideal setup can still be good enough

torpid prism Sep 9, 2019, 2:28 PM

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I have a nested collider as my characters weapon that he is holding

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using code to scale the collider game object it will make the weapon longer

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right now when scaling the collider against a wall or another object it will push the player back

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also doing so against the floor will lift the player up

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but when i aim 45 degrees towards the floor i don't get the expected result

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( getting pushed 45 degrees away from the floor )

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instead the player just gets lift up

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how can i fix this ?

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My current fix is to create holes in the floor that the weapon can get stuck inside and will allow the player to control his position in mid air via the weapon freely

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📎 unknown.png

frigid pier Sep 9, 2019, 2:40 PM

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You can use collision matrix to exclude weapon from colliding with walls, you could also draw weapon using shader on top of them so it won't go inside walls visually.

torpid prism Sep 9, 2019, 2:40 PM

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but i want it to collide

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part of the game

frigid pier Sep 9, 2019, 2:41 PM

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I'm not sure what you are trying to do then

torpid prism Sep 9, 2019, 2:57 PM

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📎 clip.mp4

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@frigid pier

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the collider will only push me upwards from the floor or sideways from the wall

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i want to aim 45 degrees and let it push me diagonally like in the clip ( but i used additional colliders to lock the player weapon )

sterile flicker Sep 9, 2019, 3:06 PM

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hey @sly violet I just used what you told me earlier that I should use a flag and destroy in FixedUpdate and that's what I did but I still get this inconsistent part where the player just go through the object instead of bouncing. Is there any other thing that I should check ? because I'm a bit lost there.

autumn jetty Sep 9, 2019, 4:27 PM

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If you create a PhysicsBody without an entity, i.e. within a script, it won't make it collideable by the dynamics/raycasts right?

torpid prism Sep 9, 2019, 5:07 PM

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I think i know how to solve that, will attach another collider via a join at the ends of the weapon with great amount of friction

wanton crater Sep 9, 2019, 6:39 PM

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how to detect particle collision with itself ("you cant" is not an option)?

coral mango Sep 9, 2019, 6:43 PM

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void IsParticleCollidingWithItself(){Return(True);}

wanton crater Sep 9, 2019, 6:45 PM

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📎 unknown.png

coral mango Sep 9, 2019, 6:46 PM

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...If that's the only problem you have with that joke

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Seriously though, I'm guessing you mean particles in the same particle system colliding with each other?

wanton crater Sep 9, 2019, 6:49 PM

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yes

coral mango Sep 9, 2019, 6:49 PM

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I don't think unity supports it out of the box, you can't even get the index of particles that create a collision event

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But you could probably write your own using the array of particle motion vectors?

wanton crater Sep 9, 2019, 7:07 PM

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how to even kill single particle?

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m_Particles[i].remainingLifetime = 0;

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doesnt work

torpid prism Sep 10, 2019, 6:12 AM

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is it possible to create a 3 body bidirectional spring joint ?

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so the main body with the largest mass will be almost static , while the 2 other bodies will use a spring joint.

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Now i want for the smaller bodies to be pushed against the floor or something for it to move the main body

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Can this effect be archived with simple unity joints ?

sly violet Sep 10, 2019, 3:58 PM

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I kind of have no idea what you're talking about, but I don't see any red flags there. 3 bodies, two/three joints, one large mass and two smaller masses, should be a relatively stable configuration.

frank moon Sep 10, 2019, 4:07 PM

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Is it possible to have a parent object that moves using forces (dynamic body type) with a child object that moves using MovePosition() (kinematic body type)?
I put a script that constantly moves on the kinematic child and another that occasionally applies a force to the dynamic parent, and while it does work, whenever the parent gets its force, the child motion stops for a short while (presumably until the parent body stops moving) before continuing.

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For context, I'm trying to make a fly-like UI image sprite that flies randomly around a certain point and gets pushed away when you run the mouse cursor over it.
So I made the fly itself move locally towards a random point in a circle around (0, 0), and put it under a parent that gets pushed when you move the mouse over it.

torpid prism Sep 10, 2019, 4:13 PM

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@sly violet i am looking for a way to use stilts in VR, so the player got a capsule and each hand can be tracked via position.
what combination of joints would be best to make the it walkable ?

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there is a clip i uploaded above : there i simply copy the stilts position over and all it does is pushes the player away from the walls & floor only in a horizontal / vertical direction, i want to use them stilts with something like friction like the real deal to be able to walk. Right now it gets stuck between two static cubes those allowing me to move

sly violet Sep 10, 2019, 4:17 PM

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Maybe ask this guy, he's friendly and working on a new version:
https://www.youtube.com/watch?v=Hn1x33Lf68I

YouTube

Henrik Hermans

Stilt Fella - Launch Trailer

Stilt Fella is out now! Download it for free at: http://henke.itch.io/stilt-fella

▶ Play video

torpid prism Sep 10, 2019, 4:19 PM

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thanks will try

nimble ether Sep 11, 2019, 5:00 PM

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Hey guys

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could anyone help me ? I'm wondering how to make those physic ish animated characters : https://twitter.com/sokpopco/status/1151486558693974016

sokpop collective (@sokpopco)

Ollie & Bollie: Outdoor Estate - out now!
https://t.co/uS3tDgGocc https://t.co/3g9Pw4fiTx

Retweets

137

Likes

822

▶ Play video

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I don't know if that's the right place to ask

coral mango Sep 11, 2019, 5:12 PM

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@nimble ether It looks like they probably cheat a lot, with a lot of the physics going into visuals

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Like, they probably drive the main body like a normal character

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But then use physics for the head and limbs just to make it look plausible

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that's how I've been doing stuff like https://i.imgur.com/gWouCwl.mp4

Imgur

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Where the feet are physical but they don't move the character, the character moves the feet

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Based on the speed and direction of the torso's movement

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In that game you linked, it almost looks like the legs are actually just using raycasts to find 'the next footstep' and drawing a line to it

nimble ether Sep 11, 2019, 5:23 PM

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ow yeah I see

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what's raycasts tho ?

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I'm a total noob, maybe that's too ambitious to begin with

coral mango Sep 11, 2019, 5:27 PM

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Basically, it is telling the program to draw a line from one place to another and tell you if it hits anything

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In this case, it is pointing a line down from the character to tell it where it hits the ground

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So for feet moving like in the video you linked, maybe it saves the foot position until the character gets too far away, and then finds a new place to put the foot

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so you get that 'jumping' from one place to another

torpid prism Sep 11, 2019, 5:29 PM

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how to convert relative position between two game objects ?

containerA
-- containerB
-- -- targetObject

How do i know the local position of targetObject in the containerB coordinate system ?

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using the target local position -> i would like to know where it sits on containerB

coral mango Sep 11, 2019, 5:30 PM

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@torpid prism Transform.localPosition

torpid prism Sep 11, 2019, 5:30 PM

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yes but its only relative to the transforms coordinates

coral mango Sep 11, 2019, 5:31 PM

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It is relative to containerB

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Because containerB is its parent

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Not sure exactly what you're trying to do

torpid prism Sep 11, 2019, 5:32 PM

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📎 unknown.png

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sorry i meant relative to containerA

coral mango Sep 11, 2019, 5:33 PM

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Oh. Just subtract the position of one from the position of the other

nimble ether Sep 11, 2019, 5:33 PM

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ok, thx Pindballkitty !

coral mango Sep 11, 2019, 5:33 PM

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Hope it helps Momo!

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Also, @nimble ether
, this tutorial covers the basics of raycasts https://learn.unity.com/tutorial/3d-physics

Unity Learn

3D Physics - Unity Learn

Explore the most important topics related to the Unity 3D Physics engine, from Colliders to Raycasting.

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Sadly, I can't draw a mammoth for you right now 😄

nimble ether Sep 11, 2019, 5:35 PM

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I'm checking it out

torpid prism Sep 11, 2019, 5:50 PM

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@coral mango so would something like this would be correct ?

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📎 unknown.png

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( using only localPosition in each nested container ) *

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so this is what i am trying to do

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📎 unknown.png

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where the camera is attach to a VR headset position

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ok nvm i found what i was looking for:

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Transform.InverseTransformPoint

torpid prism Sep 11, 2019, 6:25 PM

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i ended up with the following:

void MoveCollider()
{
    // Move inner container inverse to the head horizontal position to match body collider position  
    Vector3 head = deviceHead.transform.localPosition;
    containerInner.transform.localPosition = new Vector3( - head.x, 0, - head.z );

    // Adjust collder size and Y position 
    float h = height + head.y;
    bodyCollider.height = h;
    bodyCollider.center = new Vector3( 0, head.y - h / 2, 0 );

    // Move outer container towards the head those making the body collider "follow" the headset
    float outer_y = containerOuter.transform.localPosition.y;
    Quaternion yRotation = Quaternion.Euler( 0, bodyCollider.transform.rotation.eulerAngles.y, 0 );
    Vector3 headOuter = yRotation * deviceHead.transform.localPosition;
    containerOuter.transform.localPosition = new Vector3( headOuter.x, outer_y, headOuter.z );
}

seems to work well

flint tendon Sep 11, 2019, 6:44 PM

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Hi, in physics 2D, my background scrolling depend of the velocity of his rigidbody2D. When I increase velocity, speed of my background stay the same !! is it normal ?

uneven shore Sep 12, 2019, 2:35 AM

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I have a 2d ball (circle) character, and I want to move him by rolling. I'm currently setting the velocity on the rigidbody, which works, but it doesn't roll. I tried using addforce and even angularvelocity (without velocity), but none of them make it look good enough. Anyway to do that without faking it? (faking it being animation based)

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@flint tendon "his rigidbody2D" ? From what I have, the camera follows the character,with some lerp speed. That it, it will lerp from the current target position to the new one; so the faster the character moves, the faster the camera moves. If that helps

sly violet Sep 12, 2019, 4:47 AM

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@uneven shore : First... Have you tried AddTorque? That probably should've been your first go-to. When you say the force approach doesn't look good enough, what about it doesn't look right?

Typically you might want a high torque, high friction, and either a high angular drag or a function to reduce the amount of torque based on the current angular momentum (depending on whether you want it to keep rolling when you stop applying force or not).

uneven shore Sep 12, 2019, 6:03 AM

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@sly violet my force approach was using addForce alone, and I stitched the rotation by animation, but it might be worth revisiting.
I just quickly played with addTorque and I like the way it looks, just not sure how to tweak what I'm seeing. Currently it looks like a wheel of an engine; It starts rotating slow, then speed up over time. Physically speaking I just want the ball to move based on input, no more no less; more precise control for the user.

To be honest as I'm trying to write this sentence it feels more and more like I should just "fake" it; set the rigidbody.velocity explicitly and use animations to mimic the rolling, probably set the animator value from the current rigidbody velocity. What do you think?

flint tendon Sep 12, 2019, 10:28 AM

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@uneven shore Hi, I've fixed my problem. My variable was serialized. Then I must put it internal than public. Or use System.NonSerialized before declaring my variable 🙂

ruby scarab Sep 12, 2019, 7:35 PM

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Could someone please expain in a really basic sentence to a non natively english speaking Simon what a Contraint is?

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is it just a non-basic polygon physic shape?

bleak wedge Sep 12, 2019, 7:48 PM

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@ruby scarab a Constraint is like the hinges on a door. Without the hinges, the door would fall over on its side. But the hinges make it only rotate along the y-axis, so instead of falling it swings open

ruby scarab Sep 12, 2019, 7:49 PM

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ah thanks

bleak wedge Sep 12, 2019, 7:49 PM

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Constraints limit in what ways an object can move

neon hamlet Sep 12, 2019, 10:22 PM

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Any idea why rotation keeps accumulating when the RB does a 360 degree flip?

📎 rbrotation.jpg

torpid prism Sep 13, 2019, 4:51 AM

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@neon hamlet Its normal, that way you can use tweens and interpolation without any tricks. I used to lock at -180 to 180 degrees for specific scenarios like so

while( angle < -180 ) angle += 360;
while( angle > 180 ) angle -= 360;

neon hamlet Sep 13, 2019, 9:54 AM

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@torpid prism the thing is that the more it accumulates the more there's weird velocity problems when the transform is scaled from 1 to -1 or vice versa.

torpid prism Sep 13, 2019, 10:17 AM

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@neon hamlet strange, maybe the math under the hood is using matrix transforms, but that's just my guess. iirc the new approach to physics with DOTS using the open source mathematics package so it shouldn't be a problem to dive deep into the code if you choose to use that

neon hamlet Sep 13, 2019, 10:29 AM

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@torpid prism do you know if there's a way to reset it by chance?

torpid prism Sep 13, 2019, 10:32 AM

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@neon hamlet reset what exactly ?

neon hamlet Sep 13, 2019, 10:34 AM

#

@torpid prism that stat on the RB. The only way it goes down is if the transform is scaled to -1 on X and the object flips 360 degrees again. The velocity problems also subside the closer it gets to 0.

torpid prism Sep 13, 2019, 10:35 AM

#

i don't know

#

i mean you could always override the actual rotation in the RB inside a LateUpdate() or something

neon hamlet Sep 13, 2019, 10:45 AM

#

@torpid prism ok thank you 🙂 I'll keep trying things. It's so bizarre because even when the object is stationary for a long time, when it's scaled to -1 it acts as if there's some momentum velocity applied to it, which doesn't happen if the rotation in the "info" section is at 0.

torpid prism Sep 13, 2019, 11:06 AM

#

@neon hamlet This is very strange, maybe you are placing the rigid body on an angled surface or maybe you got some other forces moving it, it shouldn't react in the way you just described. Maybe I'm wrong and somebody with deeper knowledge could figure it out. glhf with trying to solve it.

neon hamlet Sep 13, 2019, 11:20 AM

#

@torpid prism it's stranger than that. I just manually rotated the object on Z and the rotation in the info section resets when it reaches 180, it doesn't do that when the game is running. I'm only doing AddForce(new Vector2(0.0f, 1.0f + verticalForce), ForceMode2D.Impulse); shrug

torpid prism Sep 13, 2019, 11:22 AM

#

@neon hamlet can you share a gif of when it happens ? ( sharex / ScreenToGif are 2 tools i use for gifs )

neon hamlet Sep 13, 2019, 11:23 AM

#

sure one moment

neon hamlet Sep 13, 2019, 11:42 AM

#

@torpid prism first I scale it left and right, nothing strange happens, then do two flips and rotation accumulates, then scale it left right again and it behaves strangely. This is only with two flips, when rotation is 6k+ it shakes like crazy.

📎 weird.gif

torpid prism Sep 13, 2019, 11:49 AM

#

@neon hamlet looks cool, i never actually touched 2d physics in unity ( although your first screenshot is clearly showing that it is 2D 😐 ) but the thing i would try and do on each turn is to reset all the forces and zero out the velocity of this rigid body

neon hamlet Sep 13, 2019, 11:57 AM

#

@torpid prism yes it's 2D, I'll try it and share results if useful 🙂

coral mango Sep 13, 2019, 12:03 PM

#

Can you reset the rotation to zero at the end of the flip?

grizzled jacinth Sep 13, 2019, 12:24 PM

#

gpu rigid body test with physx 4 plugin

📎 video.mov

torpid prism Sep 13, 2019, 12:29 PM

#

@grizzled jacinth ~~What is physx 4 ? is that Havok Physics for DOTS~~ nvm i found it

neon hamlet Sep 13, 2019, 12:37 PM

#

@coral mango that appears to reset the accumulation, just need to figure out how to implement it correctly, since the body can land on rotated objects.

coral mango Sep 13, 2019, 12:45 PM

#

@marble marten Divide the rotation by 360 and set it to the modulo?

#

er, sorry

#

@neon hamlet I meant

neon hamlet Sep 13, 2019, 12:55 PM

#

@coral mango I'll try that thank you. The thing I don't understand is why when manually rotating the object, the rotation accumulation goes from say -180 to +180 and starts decreasing, but when I flip the object while the game is running it just keeps adding and goes beyond +-180.

#

I feel that if I don't fix that from happening everything else will be a bug waiting to happen in unexpected situation .

torpid prism Sep 13, 2019, 12:59 PM

#

@neon hamlet isn't that when doing so in edit mode it clamps the values ( the editor script ) ?

#

use the script i added above to get the same result both in editor & play mode ?

neon hamlet Sep 13, 2019, 1:05 PM

#

@torpid prism in the editor when rotating the object Z it goes beyond +-180, but the "info" section rotation is clamped to 180, in game mode the object Z is clamped to +-180, but the "info" section rotation is not huh.....

#

Edit mode game object Z not clamped, info section clamped, Game mode object Z clamped, info section not.

coral mango Sep 13, 2019, 1:10 PM

#

They don't automatically clamp it in runtime scripts because if they did then lerps would act all weird

neon hamlet Sep 13, 2019, 1:16 PM

#

@coral mango is there any way to access the "info" section rotation during runtime and act on it, since the transform.rotation.z will not exceed +-180?

#

I'm just not sure how to implement this. The body is in motion, it can collide with other objects, when to reset the rotation to 0 so it doesn't produce weird physics results.

#

What a headache 😅

coral mango Sep 13, 2019, 1:21 PM

#

Using the modulo of rotation(in degrees)/360 doesn't do it?

torpid prism Sep 13, 2019, 1:21 PM

#

isn't rotation info is just the body rotation ?

#

https://github.com/Unity-Technologies/UnityCsReference/blob/master/Editor/Mono/Inspector/Rigidbody2DEditor.cs#L187

GitHub

Unity-Technologies/UnityCsReference

Unity C# reference source code. Contribute to Unity-Technologies/UnityCsReference development by creating an account on GitHub.

neon hamlet Sep 13, 2019, 1:28 PM

#

@coral mango not sure how to implement it. The issue occurs when rotation exceeds +-180, but this never occurs for transform.rotation.z at runtime, how to detect it so I can reset it?

#

I thought about doing it in OnTriggerEnter, so the body can freely rotate in the air, but get its rotation reset when it touches ground, so it doesn't move in weird ways when changing direction, but that trigger has proven unreliable and inconsistent.

neon hamlet Sep 13, 2019, 1:49 PM

#

Frankly, I don't know what's going on. In the console I'm printing the transform.rotation.z, the editor shows a different value and the "info" section shows a different value too.

📎 huh.jpg

#

Guess the console is in degrees?

torpid prism Sep 13, 2019, 1:58 PM

#

the info value is the physics rigidBody2D.rotation, while the transform value is the global rotation Quaternion

#

rigidBody2D.rotation is in degrees

#

Quaternions have 4 values ( x,y,z,w ) compared to Euler angles which have 3 values (x,y,z)

#

So ...
the editor shows you transform in Euler angles,
you are logging Quaternion angles,
editor info shows you rigidBody2D physics rotation

#

@neon hamlet

#

// 3D
            m_rigidBody3D.rotation = Quaternion.Euler( 0, 0, 0 );
// 2D
            m_rigidBody2D.rotation = 0f;
            m_rigidBody2D.transform.rotation = Quaternion.Euler( 0, 0, 0 );

#

but i might be wrong, again i never touched 2D physics 😛

neon hamlet Sep 13, 2019, 2:09 PM

#

@torpid prism you're a life savior 🙂

    {
        if(characterRB.rotation > 360f)
        {
            character.transform.eulerAngles= Vector3.zero;
        } else if(characterRB.rotation < -360f)
        {
            character.transform.eulerAngles = Vector3.zero;
        }
    }```

torpid prism Sep 13, 2019, 2:10 PM

#

u r clamping around 2 revolutions ( 720 degrees ) there

#

so does it work ?

neon hamlet Sep 13, 2019, 2:12 PM

#

@torpid prism when the transform.scale.x is -1 the RB rotation goes to negative 🙂 Yep works like a charm and there's no strange jitter when it's applied on every FixedUpdate() ^^

torpid prism Sep 13, 2019, 2:12 PM

#

yeet

neon hamlet Sep 13, 2019, 2:13 PM

#

@torpid prism thank you so much! 🙂 It was my mistake, didn't realize the "info" section is showing the RB rotation not the transform rotation 😦

#

Either way this is strange stuff...

#

Yey I can make my game now ^_^

torpid prism Sep 13, 2019, 2:15 PM

#

congradz

neon hamlet Sep 13, 2019, 2:20 PM

#

@coral mango thank you for your help as well 🙂 hope I can return the favor for you guys 🙂

ripe ibex Sep 14, 2019, 3:57 AM

#

so I'm trying to make player movement

#

if the player's rigidbody is dynamic, the player will be affected by physic from other dynamic bodies, which is undesirable

#

if the player's rb is kinematic, it will not collide with static objects

#

so i wonder what do people usually do to make a player that collides with static objects but isn't affected by forces

coral mango Sep 14, 2019, 4:02 AM

#

Have you looked at https://answers.unity.com/questions/209656/having-a-kinematic-rigidbody-detect-collision-with.html

Having a kinematic rigidbody detect collision with a collider with...

Unity is the ultimate game development platform. Use Unity to build high-quality 3D and 2D games, deploy them across mobile, desktop, VR/AR, consoles or the Web, and connect with loyal and enthusiastic players and customers.

ripe ibex Sep 14, 2019, 4:21 AM

#

Thanks, I think I know what I oughtta do now

sly violet Sep 14, 2019, 6:53 AM

#

That's really old. You might consider a CharacterController.

coral mango Sep 14, 2019, 1:20 PM

#

Ah, I didn't even think of that; I haven't used 3d much

torpid prism Sep 14, 2019, 2:43 PM

#

How does timeScale relates to **fixedDeltaTime **when using in fixedUpdate ?

#

im puzzled why fixedUnscaledDeltaTime exists

#

from the docs:

"If you lower timeScale it is recommended to also lower Time.fixedDeltaTime by the same amount."

#

and they show an example where deltaTime is multiplied by timeScale, so how is fixedUnscaledDeltaTime is different ?

torpid prism Sep 14, 2019, 3:40 PM

#

ok i ran some tests and the results are strange:

when changing timeScale the following will change:
- deltaTime
- fixedUnscaledDeltaTime
- smoothDeltaTime

the following will not change:
- fixedDeltaTime
- unscaledDeltaTime

#

why fixedDeltaTime does not change ?

#

here is my code, if anyone got a minute please check:
https://gist.github.com/nukadelic/c59c09aec4f709e4f4d1b4176c455bdb

Gist

Test Unity time scale and physics rigidbody jitter

Test Unity time scale and physics rigidbody jitter - TestTimeScale.cs

manic heron Sep 14, 2019, 3:59 PM

#

if i have multiple scripts on a single object that do an OnTriggerEnter event is there a way to control the order they execute?

ocean horizon Sep 14, 2019, 4:05 PM

#

@manic heron These kinds of events are sent via an internal "SendMessage" call. This call when sent to a GameObject iterates all the components on the GameObject checking if it has the appropriate method and calls it if it does. Therefore, it seems that the order is controlled by the order of the scripts on the GameObject which is something you can control by moving them up/down with the ones closest to the top being called earlier.

manic heron Sep 14, 2019, 4:07 PM

#

that doesnt seem safe

#

ill try to figure something out thanks

ocean horizon Sep 14, 2019, 4:15 PM

#

I was just indicating how the order was determined and not so much a solution on how to control it. It's not safe/recommended to rely on the order of callbacks for sure.

wintry void Sep 14, 2019, 6:58 PM

#

How do i make my character jump?

torpid prism Sep 14, 2019, 7:43 PM

#

if you are using a rigid body use AddForce and Vector3.up

wintry void Sep 14, 2019, 7:56 PM

#

i have no clue how to write code and i dont know what im supposed to do here

torpid prism Sep 14, 2019, 7:58 PM

#

learn c# join the force

#

u could also check if there any assets on the store for jumping but i doubt something like that would be usable

wintry void Sep 14, 2019, 7:59 PM

#

i cant seem to find anything

#

if there was already a preset in the oculus folder what would it be called

torpid prism Sep 14, 2019, 7:59 PM

#

https://answers.unity.com/questions/1207400/how-to-make-a-simple-jump-script-in-3d-c.html

How to make a simple jump script in 3D C# - Unity Answers

Unity is the ultimate game development platform. Use Unity to build high-quality 3D and 2D games, deploy them across mobile, desktop, VR/AR, consoles or the Web, and connect with loyal and enthusiastic players and customers.

wintry void Sep 14, 2019, 8:03 PM

#

these scripts have like 16 errors each

bleak wedge Sep 14, 2019, 8:06 PM

#

@wintry void Discord is great for asking for help for specific questions, but it's a terrible place to learn how to code. Look up some beginner C# tutorials (Brackeys is a great place to start) and work your way up from there

torpid prism Sep 14, 2019, 8:51 PM

#

@wintry void yea man youtube is your friend for rapid introduction into any field in general 👌

stone palm Sep 14, 2019, 10:25 PM

#

Is there a way to ignore colliders within child objects when using OnCollisionStay on the root object?

#

Or at the very least get both Colliders on collision so I can filter out the one I dont want to detect?

#

Without using extra layers I should add

torpid prism Sep 14, 2019, 10:41 PM

#

@stone palm what do you mean both colliders ? isn't this is one and the input argument Collision is the second one ?

stone palm Sep 14, 2019, 10:54 PM

#

I have a player object which has its own collider at the root, and a child object within that object. The child object has its own box collider which I am using for soft targeting ect. The issue is that I have a script on the root of the player that detects collisions, and I only want to detect the collider on the root, not the child object collider which is being used for something else. Since my player has a rigidbody, that means when I use OnCollision methods, all colliders are considered, even the ones in child objects.

#

I want to be able to filter out that child collider without needing to use extra layers

torpid prism Sep 15, 2019, 12:32 AM

#

u can filter via collision.gameObject.tag

drowsy idol Sep 15, 2019, 2:17 AM

#

I'm trying to create an environment where a 2D ball can be ricocheted around a screen. I'm having some issues though and it's been bouncing weirdly as shown here:

#

https://gyazo.com/f9f30db6ba54eb4443f4d2f5be29f80d

Gyazo

▶ Play video

#

Here is my code:

#

using UnityEngine;

public class RicochetScript : MonoBehaviour
{
    private Vector3 mousePosition;
    private Rigidbody2D rb;
    private Vector2 direction;
    private float moveSpeed = 60f;
    private float xDirection;
    private float yDirection;


    void Start()
    {
        rb = GetComponent<Rigidbody2D>();
    }

    void Update()
    {
        if (Input.GetMouseButton(0))
        {
            mousePosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
            direction = (mousePosition - transform.position).normalized;
            xDirection = direction.x;
            yDirection = direction.y;
            rb.velocity = new Vector2(xDirection * moveSpeed, yDirection * moveSpeed);
        }
    }

    private void OnCollisionEnter2D(Collision2D collision)
    {
       
        if(collision.gameObject.tag == "VerticalEnvironment")
        {
            rb.velocity = new Vector2((xDirection * -1) * moveSpeed, yDirection * moveSpeed);
            Debug.Log("Vertical Collision");
        } else if (collision.gameObject.tag == "HorizontalEnvironment")
        {
            rb.velocity = new Vector2(xDirection * moveSpeed, (yDirection * -1) * moveSpeed);
            Debug.Log("Horizontal Collision");
        }
        
    }
}

#

Basically, I'm just flipping the x and y directions between positive and negative by multiplying the direction by -1 but I'm pretty new to Unity, so I'm not sure if this is a scripting error, or a problem with the colliders I have set up on the walls and the ball.

#

Anyone have any ideas for other approaches I could take?

strange raven Sep 15, 2019, 2:37 AM

#

@drowsy idol Are you just doing it for the challenge? Or are you actually just trying to have a sphere bounce. If you just want it to bounce, slap a physicsmaterial2D on the ball RB with a bounce factor of 1 and a friction of 0

drowsy idol Sep 15, 2019, 2:38 AM

#

Oh, no I'm very new to unity, not aware of everything available to me yet!

#

I'm coming out of a c# background so I figured I could code something that would be semi-predictable from a gameplay standpoint but if there's something easier I'll give that a go

strange raven Sep 15, 2019, 2:39 AM

#

You can keep everything in the update function, but you don't need to check for the collision anymore if you do that.

To make a physics material just right-click in your assets folder and there will be something about physics materials like halfway down maybe. Pick the 2D one and then click on it to edit the bounce and friction

#

Drag it onto the ball in the scene view and it should work

#

You should also go into the ball rigidbody settings and turn on interpolation if it isn't already.

Also change the collision detection to continuous, it will prevent it from sometime's teleporting through the wall if it goes too fast

drowsy idol Sep 15, 2019, 2:42 AM

#

Thanks! Working perfectly now!

strange raven Sep 15, 2019, 2:42 AM

#

👍

dusky sedge Sep 15, 2019, 3:34 AM

#

I know this is such a tired and overasked question, but I feel like if I got a good fix it'll save me much trouble in the future, but what is the best way to prevent your character from falling through the floor or object when jumping from too high?

stone palm Sep 15, 2019, 3:35 AM

#

@torpid prism I'm not trying to filter the other object, i'm trying to filter which collider is colliding with the other object

dusky sedge Sep 15, 2019, 3:35 AM

#

I've contemplated using raycasts to basically stop the downward velocity.

cinder hill Sep 15, 2019, 3:44 AM

#

i mean i'm super new to unity in general, but like i guess it would depend on what you're going for

#

but like my instinct is to figure out what costs less resources to do and find a solution tht fits the game first

dusky sedge Sep 15, 2019, 3:45 AM

#

You talking to me?

cinder hill Sep 15, 2019, 3:45 AM

#

yes

torpid prism Sep 15, 2019, 3:46 AM

#

@stone palm show code

dusky sedge Sep 15, 2019, 3:46 AM

#

ok. Well, the issue here is my character collider falls just below my platform/ground collider and it is just enough to make it fall almost straight through.

cinder hill Sep 15, 2019, 3:47 AM

#

oh, lol. isn't there a field that you can set that prevents too much inbuilt clipping

#

also like, you could just set a limit on jump height and decending speed if you wanna be lazy. or make clipping a mechanic or something

dusky sedge Sep 15, 2019, 3:48 AM

#

hm. Good point. I haven't check tbh

#

Could my character controller possibly interfere with how the clipping works?

cinder hill Sep 15, 2019, 4:06 AM

#

probably. you might find your answer in the documentation tho

stuck bay Sep 15, 2019, 5:09 AM

#

im working on a car wheel and i want to make the cars wheels move. I have it rotate and i want to use friction to move it as it woul IRL

raven prawn Sep 15, 2019, 3:14 PM

#

hello all, I'm having a physics issue and was looking for some insight.

#

So, My player had a box collider and the tiles making up the ground also had box colliders but that rendered the player floating about half a pixel or so above the ground which I can't have when 32 pixels make up one unit. So I read up on the problem and switched colliders to edge colliders on everything which caused the player to fall right through the ground, until I added a capsule collider to the player which caused the player to bounce around a lot while moving. I then switched the ground collider to a Polygon collider which for some unexplained reason fixed the bobbing but put the player about an eighth of a pixel in the ground, which I could deal with, if not for the fact that when I applied the camera as a child of the player I realized that the bumps and tremors were not really gone, just near impossible to see unless you're strapped to the player. Which leads me here. What's the best collision type for a tile based pixel art game so as to allow for as close to pixel-perfect collision as possible while still maintaining a steady camera that doesn't make it look like the player's steps cause mini earthquakes?

#

And before you ask, yes the tiles are lined up absolutely perfectly, they are not the issue. It happens even on elongated tiles stretched on the X axis for testing purposes.

quick tusk Sep 15, 2019, 6:40 PM

#

anybody have a good way to make 2d soft bodies?

coral mango Sep 15, 2019, 7:32 PM

#

Spring joints, I suppose?

#

What is a good way to make a 2d physics object face the direction of its velocity(in the manner of an arrow)?

#

@quick tusk A lot would depend on the specific sort of softbody you wanted, but a rigged 2d object can use all sorts of joints, IK, etc on the bones

quick tusk Sep 15, 2019, 7:40 PM

#

i mean like

#

blob physics

#

im messing with springs right now

#

i got a pretty ok blob cube

#

with 4 points

#

and a square of springs with an x inbetween them

#

but the amount of springs would go up exponentially with more points

sly violet Sep 15, 2019, 7:46 PM

#

Uhhh... Usually you just put springs between adjacent nodes.
That being said, the physics solver tends to have difficulty as the number of connected nodes increases, especially if they're similar in mass.

#

One approach you could use is to have a heavy central rigidbody and light outer rigidbodies that each have a spring to the center.

quick tusk Sep 15, 2019, 7:47 PM

#

the adjacent node method ended with a pile of nodes

sly violet Sep 15, 2019, 7:47 PM

#

That acts like a squishy ball.

quick tusk Sep 15, 2019, 7:47 PM

#

OH i just need a real high frequency

#

wait no i remembered why it didnt work

sly violet Sep 15, 2019, 7:49 PM

#

@coral mango : If I need a physics object to look like it's facing the direction of its velocity, I usually make it incapable of rotation, and then put its sprite/mesh on a child object. Then you can just assign the sprite's transform.up (or left or whatever) to the velocity vector.

coral mango Sep 15, 2019, 8:05 PM

#

@sly violet It still needs to collide properly, so the actual physics body needs to at least somewhat aimed. Or at least its collider does

sly violet Sep 15, 2019, 8:09 PM

#

@coral mango : What do you expect it to do if something hits it in such a way that it should be sent spinning?

coral mango Sep 15, 2019, 8:11 PM

#

I expect it to go kinematic and become a child of whatever it hit, because that is what it already does

sly violet Sep 15, 2019, 8:19 PM

#

So what's moving it in the first place? Anyway, you can always set its rotation directly in the rigidbody (which can cause weird collisions but apparently that doesn't matter), or use AddTorque if you find you do need proper physics (but that's hard to tune).

coral mango Sep 15, 2019, 8:22 PM

#

looks a bit silly

📎 aim2.gif

#

without facing the direction. I could set initial direction, of course, but then it would look stupid when falling

#

I should mention that the actual collision shape is a circle, on the arrowhead

#

the shaft collider is activated upon going kinematic, to sere as a platform

simple pond Sep 15, 2019, 9:30 PM

#

Just aim/rotate the arrow as it changes direction in flight...

coral mango Sep 15, 2019, 9:52 PM

#

...yes, that was the idea. I was asking about the best way to do exactly that.

sly violet Sep 15, 2019, 10:25 PM

#

🤦 After all that, it's just a circle collider anyway? It's rotation doesn't matter. Just lock the rotation of the rigidbody and set the sprite rotation by setting it's transform.right equal to the velocity. Of course, that'll only work if the sprite and circle collider have the same center, although you can fake that by adding objects in the hierarchy. Then, when you switch to the kinematic shaft, align the shaft with the sprite.

coral mango Sep 15, 2019, 11:06 PM

#

I ended up doing basically that.

simple pond Sep 16, 2019, 1:51 AM

#

@coral mango I see no question... so if you were asking anything it was not apparent to me.

coral mango Sep 16, 2019, 2:13 AM

#

@simple pond the question was asked and answered before your post 😛

simple pond Sep 16, 2019, 2:13 AM

#

oh duh >_<

#

ok

coral mango Sep 16, 2019, 2:13 AM

#

😛

#

Thanks anyway, though!

simple pond Sep 16, 2019, 2:13 AM

#

😄

coral mango Sep 16, 2019, 2:14 AM

#

Now I just have to completely redo the jumping

#

now that I have shooting working well

#

Maybe the entire movement for that matter

#

Anyone have some good solid feeling examples of 2d physics platformer controls?

versed pike Sep 16, 2019, 8:02 PM

#

heyo, does anyone know how to make a bouncy ball that doesn't gain KE each time it hits the ground?

#

i already did some research and I found that the way to do it is to set the collision collider detection to continuous, but it doesn't work for me

#

what am i doing wrong?

coral mango Sep 16, 2019, 8:13 PM

#

Well, there is no way to do it without ANY cheating, because unity's physics aren't precise enough to perfectly conserve energy

#

You'll need to either add or remove velocity at some point if you need it to maintain it perfectly.

versed pike Sep 16, 2019, 8:29 PM

#

that's sad :(. i was hoping the physics in unity would be realistic.

sly violet Sep 16, 2019, 8:41 PM

#

The physics will never be perfect, but, uhhh... Just set the bounciness to less than 1. After all, there's no such thing as perfect bounciness in real life.

cunning pond Sep 16, 2019, 8:54 PM

#

I am trying to get a rigidbody to stay on the surface of a moving and rotating platform. How can I achieve this?

coral mango Sep 16, 2019, 9:15 PM

#

a rigidbody or a charactercontroller?

#

charactercontrollers will 'stick' to moving platforms, normal rigidbodies you'd need to either parent the object to it or add it's movement to the other rigidbodies with MovePosition or something

sly violet Sep 16, 2019, 9:29 PM

#

@cunning pond : First, make sure you have some friction. Second, make sure the platform is moving and not teleporting - lots of people mistake lots of small teleports for movement, but it's not the same thing.
Basically if the platform is kinematic, you need to be using MovePosition and MoveRotation.
If the platform isn't kinematic, that won't work and it needs to move with AddForce/AddTorque (or a joint/engine, or velocity, or some other physics-compliant movement rather than just setting position).

cunning pond Sep 16, 2019, 10:03 PM

#

It is a player on a boat in the ocean. Both the player and the boat are not kinematic.

lapis plaza Sep 16, 2019, 10:08 PM

#

@versed pike what is KE?

cunning pond Sep 16, 2019, 10:37 PM

#

How would I measure the change in position each update?

sly violet Sep 16, 2019, 10:47 PM

#

@cunning pond That sounds like a case for just having a decent amount of friction.

#

If neither object is kinematic and they're both just being moved by forces (are they?) then there's no particular reason the player should fall off - aside from the normal forces of a pitching boat, perhaps.

cunning pond Sep 16, 2019, 10:55 PM

#

@sly violet that works but I would like to walk around the boat.

sly violet Sep 16, 2019, 11:02 PM

#

As I said, if it's moving by forces, that should just work.

Otherwise, well, then you have to decide exactly how much physics you want to replicate and how to replicate it. How are you moving the player now? If you're currently setting the player position in world space, one trick you might use is to simply move the player in the boat's space instead of world space. You can do this by making it a child and using it's "local" parameters, or by using the Transform.*Transform* commands, particularly Transform.TransformVector.

cunning pond Sep 16, 2019, 11:12 PM

#

I can't make it a child for network reasons.

sly violet Sep 16, 2019, 11:18 PM

#

Transform.TransformVector

cunning pond Sep 16, 2019, 11:29 PM

#

Sorry, my brain is just a bit hazy today. How would i move the player from world to boat space?

#

I'm currently using a character controller with root motion.

sly violet Sep 16, 2019, 11:38 PM

#

Now you finally mention it's a CharacterController - literally the first thing anybody asked.

#

Kinda outside my expertise, but I thought those are supposed to stick automatically.

cunning pond Sep 16, 2019, 11:50 PM

#

I misspoke, it is NOT using a CharacterController™. Rather the script and animator that controls my character uses root motion.

#

It is actually the old standard assets 3rd person character setup.

coral mango Sep 17, 2019, 2:18 AM

#

Anyone know a fairly simple way of faking damped motion on an object? wanna do some very basic 'jiggle' on a 2d bone without a full physics object, etc.

coral mango Sep 17, 2019, 6:59 AM

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So attaching a kinematic rigidbody to another rigidbody via parenting seems to be kinda bad. Is there a better alternative?

last hound Sep 17, 2019, 7:38 AM

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best way to handle terrain collision testing in a large open world procedural game? I couldn't even get rigidbody to work right, so I've just defaulted to using ECS to store all x, y, z data and building my walls really steep (but I have the rooms to spend some resources on Terrain Collider if I could just get it working (would I have to control the character with AddForce() ?

last hound Sep 17, 2019, 11:01 PM

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kind of a mix of built in colliders and hardcoded collision data?

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relatively flat most places, but mountains just aren't happening w/o terrain collider

uneven shore Sep 18, 2019, 5:04 AM

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Up until now I've been using rigidbody2d.velocity = inputX * Speed * Time.fixedDeltaTime to move the character.
I now want to add a charge, where the player can hold a button, charge for a few seconds, then release. I was thinking on using it with .AddForce(), but my velocity code above will overwrite it. Any ideas how I can implement it together with the velocity code?

coral mango Sep 18, 2019, 6:15 AM

#

Anyone familiar with the 2D CCD/fabrik IK solvers? I'm having a weird issue.

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@uneven shore might be best to not set the character's velocity that way

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That will stop them from being accelerated by other things like gravity and being hit by things

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So at that point it might as well be kinematic

simple pond Sep 18, 2019, 9:34 AM

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@uneven shore and @coral mango the thing about that type of physics manipulation is that it will force Unity to recompute things on collision, which can be quite expensive. you can achieve the same with AddForce(magnitude * direction, ForceMode.VelocityChange); this will use the engine more readily

coral mango Sep 18, 2019, 9:35 AM

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Yeah, that was kinda what I was getting at. My point was that the same problem they had with jumping would apply to ALL physics if they keep setting the velocity that way.

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Which is generally bad 😄

simple pond Sep 18, 2019, 9:37 AM

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^ 😄

ocean horizon Sep 18, 2019, 1:23 PM

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To note, setting velocity directly has no impact on performance whatsoever. The forces you add just get accumulated until the simulation step at which point they are added to the velocity anyway then the solvers run. Whether you do this or the physics system sums up forces and then does it for you makes no difference.

coral mango Sep 18, 2019, 1:54 PM

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Performance aside, at the end of the day he asked why his character couldn't jump and the answer is because every step where he did so he then immediately set the velocity to erase the force he added 😄

#

Good to have that clarification though; I had kinda wondered about that.

ocean horizon Sep 18, 2019, 2:04 PM

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Well another clarification may help too then; if you add a force then set velocity, the accumulated force will still adjust that velocity when the simulation runs so won't be cleared. Of course, this won't be the case if you add an impulse which immediately modifies the velocity there and then.

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I agree though, this is the inherent "danger" of modifying velocity. You have to be aware of what you're potentially overriding. The most common one I see is setting velocity each update and wiping out any velocity created via gravity and also add a force then setting velocity to zero and wondering why the force is still added.

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Maybe exposing the "totalForce" on a Rigidbody2D via a get/set would help too. Minor thing that never got added but potentially useful.

coral mango Sep 18, 2019, 2:08 PM

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That sounds like it would be really handy. It would have helped a LOT when I was trying to make moving platforms move stuff resting on them

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(since the 2d doesn't have a charactercontroller)

ocean horizon Sep 18, 2019, 2:09 PM

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There's also a feature in Box2D that controls whether this "force sum" is reset each simulation step. That could be turned on/off too.

coral mango Sep 18, 2019, 2:12 PM

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That sounds useful.

#

Speaking of things with inscrutable controls, I was having an odd problem with the 2D IK chains.

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Specifically this setup, where the braids are children of the head but not 'attached' to it.

📎 unknown.png

ocean horizon Sep 18, 2019, 2:14 PM

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This isn't something I'd know, it's not the 2D physics system.

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Although any questions I can direct to the 2D devs that deal with this.

coral mango Sep 18, 2019, 2:15 PM

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That would be appreciated!

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For some reason, when adding either CCD or Fabrik solvers to the chains, they wouldn't activate until I added enough links that the head was affected.

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Eventually, after several re-edits of the sprite mesh, it was suddenly possible to add them properly. So I'm not sure if there is some condition that isn't listed that I might've run afoul of.

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Oh, actually, I do have a 2d physics system question that's been nagging at me.

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Is there a 'correct' way to parent a kinematic rigidbody to another rigidbody so that it will stick to it without slipping off?

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In this case, I've had two types of trouble with that- the big one being physically simulated arrows that, upon hitting an object, go kinematic and child themself to whatever they hit. This works really well, except that sometimes(usually with rotating objects) this makes the physics go wonky.

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And in a similar but smaller way trying to attach joints to an animated kinematic rigidbody caused the connected body to kinda... 'slide off' over a shirt time. Not quite the same issue, but in the same neighborhood it seems?

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...Sorry for the bombardment there >.>

ocean horizon Sep 18, 2019, 2:24 PM

#

The actual physics system doesn't understand hierarchy. The way it works is that when the simulation step has run, the positions of the bodies are written back to the transform system. Importantly, this is done in order of their transform depth so root first, then children (by depth).

#

Let's say you have a dynamic body on the root transform and the child has nothing but its child has another dynamic body. When the simulation ends, the dynamic body on the root will write to the root transform naturally respositioning the child transform too but the child transform of that child will be positioned a the position of the other dynamic body. This means the hierarchy is effectively split by the dynamic bodies.

#

For kinematic bodies the rules are similar but subtly different. A kinematic body not at the root will not write its position to the transform. This means that if any parent rb writes to the transform then the position is maintained

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So if you add a kinematic body in a hierarchy it will follow any parents

#

Again, this is purely an artifact of the transform write-back and not physics

#

only joints can create constraints like that.

#

So to actually answer your question directly.....

torpid prism Sep 18, 2019, 2:28 PM

#

Hi i have created a physics based character controller in VR, now i want to add a rope that will behave something similar to how spider man swings between buildings. Is it necessary to attach rigid bodies to the hands controllers or is there a way around it ?

ocean horizon Sep 18, 2019, 2:29 PM

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You should just be able to add a kinematic body in the child hierarchy and it should just work with the parent i.e. its position is submissive to any parent

coral mango Sep 18, 2019, 2:29 PM

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Yeah, normally I can- except that sometimes it freaks out.

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Usually when the parent rotates.

ocean horizon Sep 18, 2019, 2:30 PM

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well you'd need to submit a reproduction case because rotation of the parent isn't any different than position; it's just a pose and the kinematic child doesn't write to the hierarchy at all

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The problem though is that Unity has a Transform hierarchy which isn't represented in the physics system

coral mango Sep 18, 2019, 2:32 PM

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I can try to get a screenshot or the like but it is hard to reliably reproduce so I'm not sure quite what triggers it. It might just be more noticeable with rotation.

ocean horizon Sep 18, 2019, 2:32 PM

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so if you end up mixing real physics constructs like joints with inferred hierarchy which is just a rule saying if/when it should write its pose then you can get into trouble

coral mango Sep 18, 2019, 2:33 PM

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The actual effect I see is that the child object(which is kinematic) ends up sort of sliding out of position relative to the parent. It is still clearly a child, since it follows along with it, just not in the correct position.

ocean horizon Sep 18, 2019, 2:33 PM

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Why does the kinematic body move? I mean it cannot react to forces in any way so the only way is that the transform is being animated or something directly is being done to the body

coral mango Sep 18, 2019, 2:34 PM

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I have no idea why.

#

But it definitely happens.

ocean horizon Sep 18, 2019, 2:34 PM

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It's just Unity in many ways is a mix of things, all of which need to work together and sometimes they are actually opposing things so it can be easy to shoot yourself in the foot.

#

What version of Unity is this?

coral mango Sep 18, 2019, 2:35 PM

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2019.3.0a4

ocean horizon Sep 18, 2019, 2:36 PM

#

If you can produce a simple reproduction case and send me the case number I'd be happy to take a look at it. Alternately just dump the project here: https://oc.unity3d.com/index.php/s/Rn0HjdiLtYoXZCs

#

You should try turning off the simulation for that child Kinematic body to see if the child transform pose still changes. If so then it's something else modifying the child transform (https://docs.unity3d.com/ScriptReference/Rigidbody2D-simulated.html)

coral mango Sep 18, 2019, 2:38 PM

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https://i.imgur.com/0lPPIyY.mp4

Imgur

ocean horizon Sep 18, 2019, 2:38 PM

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Yeah, I don't doubt you're experiencing something but without a repro it's hard to help further.

coral mango Sep 18, 2019, 2:38 PM

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Yeah, that was just to explain what I meant

#

I'll need to figure out how to make an example

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without mailing off the whole game:D

ocean horizon Sep 18, 2019, 2:40 PM

#

Try isolating it. turn off animation, the simulated prop above etc

coral mango Sep 18, 2019, 2:40 PM

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Or I could send you the script being used?

ocean horizon Sep 18, 2019, 2:40 PM

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It's going to be hard to see what's going on from just a script. Need a simpler reproduction case really

coral mango Sep 18, 2019, 2:40 PM

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gotcha

ocean horizon Sep 18, 2019, 2:41 PM

#

Doesn't look like it'd be that hard to reproduce. Reparent something with respect to another and have both bodies impact stuff. Not sure.

#

When it happens, have you paused it and inspected everything to ensure that the hierarchy is what you expect etc?

coral mango Sep 18, 2019, 2:42 PM

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Yes.

#

And that video is actually more dramatic of an example than I usually see.

#

And all I actually do in the script is rb.isKinematic = true; GetComponent<Collider2D>().enabled=false; transform.SetParent(hit.gameObject.transform);
Is that the correct way to do it, or is there something else I should be doing there?

#

I'll try to put together a proper example scene

ocean horizon Sep 18, 2019, 2:46 PM

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Note: rb.isKinematic is obsolete, you should use rb.bodyType

#

not sure why the collider is disabled or what collider that actually is attached to.

#

This is why you need a reproduction case; too many questions and unknowns

#

Can spend hours typing when a reproduction case makes it clear.

#

Understand that can be difficult sometimes though. 😦

coral mango Sep 18, 2019, 2:48 PM

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Right. The disabled collider is the one on the arrowhead. I disable the arrowhead collider so that built up arrows don't block other things from colliding before the arrow despawns.

#

And I totally understand that!

#

So rb.bodyType = kinematic would be the correct way to do that?

ocean horizon Sep 18, 2019, 2:50 PM

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https://docs.unity3d.com/ScriptReference/Rigidbody2D-bodyType.html

#

There's a https://docs.unity3d.com/ScriptReference/RigidbodyType2D.html

#

Is there a reason why you need to have a kinematic body at all on the child?

#

Why can't it just be visual? I presume this is the arrow?

coral mango Sep 18, 2019, 2:51 PM

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It falls off before it despawns, as a normal physics object

ocean horizon Sep 18, 2019, 2:52 PM

#

you could just turn off the simulation for it which is super quick; far quicker than changing the body type

#

then turn it back on when you want it to react again

#

again, there's a bunch of mechanics I'm probably missing so..

coral mango Sep 18, 2019, 2:54 PM

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That sounds completely reasonable.

#

I've only spent about a month and a half on learning unity and I am very open to learning 'the right way' to do this stuff.

ocean horizon Sep 18, 2019, 2:54 PM

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it's actually very quick to do it too. all physics objects are left in-place; they just go dormant (joints, bodies, colliders etc)

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far faster than enabling/disabling the whole GO etc

coral mango Sep 18, 2019, 2:55 PM

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A lot of this is literally throwing stuff together and(in this case literally) seeing what sticks.

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Have an example of how to do it correctly?

ocean horizon Sep 18, 2019, 2:55 PM

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Understand. We're all learning something sir.

#

Okay so I have a GitHub test project that demonstrates a lot of things in Unity 2D physics: https://github.com/MelvMay-Unity/UnityPhysics2D

GitHub

MelvMay-Unity/UnityPhysics2D

Examples of various Unity 2D Physics components and features. - MelvMay-Unity/UnityPhysics2D

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Load-up this scene: https://github.com/MelvMay-Unity/UnityPhysics2D/blob/master/Assets/Scenes/Rigidbody/Rigidbody2D_Simulated.unity

GitHub

MelvMay-Unity/UnityPhysics2D

Examples of various Unity 2D Physics components and features. - MelvMay-Unity/UnityPhysics2D

coral mango Sep 18, 2019, 2:56 PM

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cool, I'll check that out.

ocean horizon Sep 18, 2019, 2:56 PM

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But it's just setting that property above to true/false. Nothing else is required.

#

You don't get any movement from the body, the colliders don't contact anything and joints stop working.

coral mango Sep 18, 2019, 2:57 PM

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So when you say turn off simulation, you mean Rigidbody2D.simulated?

ocean horizon Sep 18, 2019, 2:57 PM

#

Yes

coral mango Sep 18, 2019, 2:57 PM

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I'll try that.

ocean horizon Sep 18, 2019, 2:57 PM

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You can do it via script and it's also in the inspector on the Rigidbody2D

coral mango Sep 18, 2019, 2:58 PM

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Most importantly, I can presumably do it from the animator?

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(It is always slightly distressing when I find a property that can't be animated, like the scale of a orthographic camera)

ocean horizon Sep 18, 2019, 3:01 PM

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You can animated it AFAIK but like anything physics, don't animate it too frequently. When you turn it on it has practically no performance impact. When you turn it off, it has a little overhead but that's only destroying any contacts on any attached colliders. It is a very small impact so not something to worry about but just be aware off.

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I'd need to check if it's excluded in the source. 1 sec

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Yep, it's animatable.

coral mango Sep 18, 2019, 3:04 PM

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I'm more of an animator than a programmer, so I've been increasingly using the animator to drive behavior. Which USUALLY works, until it suddenly doesn't 😄

ocean horizon Sep 18, 2019, 3:04 PM

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btw: regarding your IK question above; can you post that on the 2D forums and I'll direct the 2D devs to it.

coral mango Sep 18, 2019, 3:08 PM

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Sure

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Ah, so one problem. It seems that setting the physics to not be simulated also causes the colliders attached to the arrow to not function

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I'm strongly considering just making the arrows not stick to dynamic rigidbodies

ocean horizon Sep 18, 2019, 3:29 PM

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Yes, as I said that's what it's for.

coral mango Sep 18, 2019, 3:33 PM

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Is there a way to stop simulating the rigidbody but still have its colliders act as colliders(like any non-rigidbody with a collider)?

ocean horizon Sep 18, 2019, 3:34 PM

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That doesn't really make sense. What should the colliders actually do if the body stops simulating?

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If the block is rhe parent and the arrows are the children then when you make them children you can always just remove the rigidbody on the arrow. Then the arrow collider(s) attach to the parent "block" rigidbody

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colliders always attached to a rigidbody on the same GO but if one's not there then they connect to the nearest one in the parent hierarchy

coral mango Sep 18, 2019, 3:41 PM

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Though I think that biggest thing I've learned from all this: next time use bullets. 😄

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All hitscan all the time

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Thanks for all the help!

ocean horizon Sep 18, 2019, 3:51 PM

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You're welcome. Post me that link on 2D IK when you get a chance and I'll ask a 2D dev to reply.

torpid prism Sep 18, 2019, 3:56 PM

#

Hi i have created a physics based character controller in VR, now i want to add a rope that will behave something similar to how spider man swings between buildings. Is it necessary to attach rigid bodies to the hands controllers or is there a way around it ?

flint tendon Sep 19, 2019, 6:27 AM

#

Hi, does Gimbal Lock exist in 2D or it's just for 3D ?

hollow echo Sep 19, 2019, 6:55 AM

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If your rotations are in 2D then it's represented by one number and you cannot get gimbal lock

hollow echo Sep 19, 2019, 7:52 AM

#

Documentation
Physics Manual: https://docs.unity3d.com/Manual/PhysicsSection.html
Unity Physics (ECS): https://docs.unity3d.com/Packages/com.unity.physics@latest/index.html
Havok Physics (ECS): https://docs.unity3d.com/Packages/com.havok.physics@latest

Github
Physics 2D Examples: https://github.com/MelvMay-Unity/UnityPhysics2D

Youtube
Overview Of Havok Physics: https://www.youtube.com/watch?v=Uv7DWq6KFbk

Debugging Physics Messages
https://help.vertx.xyz/?page=programming/physics-messages
Collision Action Matrix
https://help.vertx.xyz/?page=info/collision-matrix

#

flint tendon Sep 19, 2019, 10:44 AM

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@hollow echo thanks a lot 🙂

karmic parrot Sep 19, 2019, 1:01 PM

#

Hi, guys, not sure if im writing into a correct channel, but hopefully someone will be able to help me out. Is there any way to get mesh colliders to work with ontriggerenter function? problem is that it hits multiple times on trigger enter and on trigger exit, even though im moving the mesh collider object inside of a trigger area. If i change the collider to box collider, there is no issue.

#

the hack of setting bool to true when entered and false when left didn't work

flint tendon Sep 19, 2019, 1:30 PM

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@karmic parrot Hi, perhaps add rigidbody and change "collision detection" option

karmic parrot Sep 19, 2019, 1:31 PM

#

the mesh collider object already has a rigidbody

#

and as i was saying, if I change the collider from mesh to box, it works just fine

drifting wind Sep 19, 2019, 1:36 PM

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@karmic parrot You should simply be able to add the MeshCollider, toggle the isTrigger option to true, and add a Rigidbody. Then attach your script to the MeshCollider and you should be able to use those OnTriggerEnter / OnTriggerExit methods.

#

If you're still having some trouble, take a screenshot showing the inspector of your object with the MeshCollider.

karmic parrot Sep 19, 2019, 1:38 PM

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I don't want that object to be a trigger. I want it to do something when I enter into a box collider, which is a trigger, area

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https://answers.unity.com/questions/1189025/ontriggerenterontriggerexit-called-multiple-times.html?fbclid=IwAR0Hnb46Wg7W9NZ-NJqYUhEjHH2eIJJb9cYEFuariKRrA3U0m6gvoLjj4IQ

OnTriggerEnter/OnTriggerExit called multiple times with MeshCollid...

Unity is the ultimate game development platform. Use Unity to build high-quality 3D and 2D games, deploy them across mobile, desktop, VR/AR, consoles or the Web, and connect with loyal and enthusiastic players and customers.

#

here, this question sums up my problem perfectly

#

and that hacky way of a response did not fix it for me

#

and as this question is from 2016, i thought that maybe there is a better solution in 2019?

sly violet Sep 19, 2019, 4:18 PM

#

@karmic parrot : That's weird. Can you describe what you're doing and the behavior you're experiencing in more detail? Things I want to know:
Is the trigger moving? If so, by what API calls?
What API calls are moving the mesh's rigidbody?
What exactly is the sequence of Event method calls you're receiving, by frame?

#

...
Checking over the "hacks" you linked to, they're not very robust. You might try having an "inTrigger/triggerDetected" flag set if we can't work out anything else:

void FixedUpdate() {
    inTrigger = triggerDetected;
    triggerDetected = false;
}
void CheckInTrigger() {
    triggerDetected = true;
    if (!inTrigger) {
        inTrigger = true;
        DoSomething();
    }
}
void OnTriggerEnter() { CheckInTrigger(); }
void OnTriggerStay() { CheckInTrigger(); }```
This works by not assuming anything beyond the notion that at least one Enter or Stay will happen every frame that you're in the trigger.

sly violet Sep 19, 2019, 4:49 PM

#

An entire FixedTimestep would have to pass without any call to OnTriggerEnter or OnTriggerStay before "DoSomething" could be called again.

flint tendon Sep 19, 2019, 6:04 PM

#

Hi, I'm using Quaternion.LookRotation in 2D. I want red form track to my character rotating along Z axis (in an x,y plane) . But I've an unespected rotation as you can see on the second image with a 3D view when I launch game. So what the matter please ? thanks

📎 Capture_decran_2019-09-19_a_19.58.03.png

#

📎 Capture_decran_2019-09-19_a_19.58.24.png

#

📎 Capture_decran_2019-09-19_a_20.04.37.png

sly violet Sep 19, 2019, 6:19 PM

#

I wouldn't bother with LookRotation in 2d. Try

transform.up = direction;```
Or transform.left, or whichever direction the sprite is supposed to be facing.

flint tendon Sep 19, 2019, 6:28 PM

#

@sly violet thanks. I'm try it

#

@sly violet I don't understand very well your answer, so I can't apply it well 😦

sly violet Sep 19, 2019, 6:41 PM

#

@flint tendon : Just replace "transform.rotation={Quaternion}" with "transform.{direction}={vector}"

#

A Sprite's "forward" direction is straight towards the screen, so the various "look" functions don't work well with them (as they point "forward").

#

But you can point their up, down, left, or right in 2d space by simply setting transform.up = MyVector2 (for example).

flint tendon Sep 19, 2019, 6:56 PM

#

@sly violet Ok thanks a lot, that's works very well. Going to study and understand this code now ^^

flint tendon Sep 19, 2019, 9:35 PM

#

@sly violet I can understand an expression like this : m_Rigidbody.velocity = transform.right * m_Speed; (in Unity manual exemple). But in transform.up = direction, my brain sucks .. can you explain me please ?

sly violet Sep 19, 2019, 9:38 PM

#

So, transform.up returns a normalized vector that points "up" from the position of its GameObject. That's how you use it when you're reading it. But you can also set it, in which case it rotates the GameObject such that the direction "up" from that GameObject is in the direction of the vector you provided to it. (Note that the vector you provide doesn't have to be normalized - which BTW means having a length of 1.)

#

So if you have a vector, and you want a GameObject to point a given direction along the length of that vector, setting transform.up (or .down or .left or .right or .forward or .back) is really the shortest way to do it.

flint tendon Sep 19, 2019, 9:44 PM

#

@sly violet perfect, thank you very much 🙂

winter bluff Sep 19, 2019, 9:44 PM

#

Can someone help me with making my character jump?

flint tendon Sep 19, 2019, 9:45 PM

#

@winter bluff more informations please ?

#

3D or 2D ?

winter bluff Sep 19, 2019, 9:46 PM

#

3d I'm new to Unity I'll explain in more detail

#

I want to make some kind of parkore game where in you are a ball. I have it right now so the ball can move around and the camera follows it.

sly violet Sep 19, 2019, 9:49 PM

#

What API calls are you using to move the ball? AddForce, AddTorque, position=, MovePosition, CharacterController, something else?

#

Also, are you playing a hamster? Sounds cool. 😎

winter bluff Sep 19, 2019, 9:52 PM

#

Add force to move forward/back add velocety to move left/right. Add torque to rotate the ball left/right. I have a jump function but it just adds a force and you can just hold the space bar and go for ever.

#

Is there a way that I can say after the ball leaves the ground that the jump force is disabled?

#

I'm in C#

#

Also I guess it could be a hamster that would be funny

sly violet Sep 19, 2019, 9:53 PM

#

Yeah, there's a few different approaches that will work.

#

Perhaps the easiest is to just use a raycast down and see if there's a collider directly beneath the player a short distance.

winter bluff Sep 19, 2019, 9:55 PM

#

I will try

#

Is a Ray cast something that detects distances?

sly violet Sep 19, 2019, 9:55 PM

#

Something like

if (Physics.Raycast(MyBall.position, Vector3.down, BallRadius + 0.1f) Jump();```

#

In this case you probably just need a short raycast that merely determines if there's anything there at all. There's a pile of tools if you need them, though; you can specify exactly what Layers are detected, whether triggers count, you can collect one or more hits to find out what's there, and so on.

#

https://docs.unity3d.com/ScriptReference/Physics.Raycast.html

winter bluff Sep 19, 2019, 9:57 PM

#

Thank you. I will try it out

flint tendon Sep 19, 2019, 10:00 PM

#

@sly violet BTW == by the way ?

#

no no, it's in your answer. I'm not anglophone. What BTW does it mean ?

#

== was a syntaxic joke

sly violet Sep 19, 2019, 10:03 PM

#

Ohhhh sorry. Yeah BTW is short for "by the way".

flint tendon Sep 19, 2019, 10:03 PM

#

ahahah 🙂 thx

sly violet Sep 19, 2019, 10:04 PM

#

...I deleted my dumb response, lol.

flint tendon Sep 19, 2019, 10:07 PM

#

too late, I've screeshoted it !!

winter bluff Sep 19, 2019, 10:31 PM

#

Pyrian thank you so much that was a lot easier than I thought and it works really well.

stuck bay Sep 20, 2019, 10:32 AM

#

everyone, hi!
I have some strange problem with hingejoint`s2d:
https://media.giphy.com/media/UUtpSZjYy61YZsddNb/giphy.gif
How you can see object rotate outside of the preferred area... and i dunno what i did wrong. Can somebody help me pls?

Giphy

hollow echo Sep 20, 2019, 10:35 AM

#

@stuck bay as I said in #💻┃unity-talk

Never mess with physics via the transform inspector

#

Is this actually a problem when you rotate via physics forces?

stuck bay Sep 20, 2019, 10:44 AM

#

@hollow echo I have the same problem, when i leave body of my character as ragdoll... so there is problem

#

My character fall on the ground and behave wrong

#

but in this moment only colliders, rigidbody`s and hingejoints work on it

ocean horizon Sep 20, 2019, 10:53 AM

#

Modifying the Transform in the inspector is just instantly changing the pose, it cannot be constrained by physics. Outside of doing this, if you're seeing it go out of constraint limits and you're sure you're not directly setting positions/rotations on transform then it might be the gizmo issue on HingeJoint2D. This was fixed here: https://issuetracker.unity3d.com/issues/hingejoint2d-angle-limits-are-not-respected-when-connected-objects-rotation-is-not-0

Unity IssueTracker - HingeJoint2D Angle Limits are not respected w...

How to reproduce: 1. Open the attached project ("HingeJointBug") 2. Enter the Play Mode Expected result: both Hinge Joints move in t...

stuck bay Sep 20, 2019, 10:57 AM

#

@ocean horizon I using unity 2018.4.9f1 do this means i have no chance to work with it?

ocean horizon Sep 20, 2019, 10:57 AM

#

The gizmo is being drawn wrong in that version, There's only so many backports we do and are allowed depending on severity.

#

Might want to try using the later version to verify this is indeed the issue

stuck bay Sep 20, 2019, 11:00 AM

#

Okay... i`ll try! Thanks. In my gif its looks really like wrong gizmo drawning

ocean horizon Sep 20, 2019, 11:00 AM

#

I can investigate the possibility of backporting to LTS but the rules are much stricter there.

#

Although this fix is trivial.

stuck bay Sep 20, 2019, 11:01 AM

#

This looks too critical from my point like for LTS...

ocean horizon Sep 20, 2019, 12:17 PM

#

@stuck bay Good news, I can backport this to 2018.4. I've got a PR up and running on the build farm and QA will test it on Monday. No idea which 2018.4 as it depends when it lands.

stuck bay Sep 20, 2019, 12:24 PM

#

@ocean horizon Looks like it really fixed my problem, after i migrated to unity 2019.2.5f1!
You are life saver! However we always need all fixes in LTS version, cause we waiting rock stability from it, when we using it besides last versions. Thanks again!

ocean horizon Sep 20, 2019, 12:28 PM

#

This isn't a stability issue though, it doesn't affect the joint. If all bug-fixes were always pushed back to LTS then it wouldn't be stable. Many factors determine whether it's allowed or not.

#

This fix however is so trivial and is completely isolated from everything else so it was deemed safe enough but needs a QA pass to check

#

LTS is taken very seriously so it must pass the measure. 🙂

stuck bay Sep 20, 2019, 12:29 PM

#

Also i think configuring limits on joint`s will be much easier, if we will see how actually object will be rotated or looked on edge of position... hm-m

full heron Sep 20, 2019, 4:33 PM

#

Does anybody know how I could go about simulating cloth physics? It doesn't need to be too realistic, but I need it to respond to colliders other than sphere and capsule colliders, unlike the built-in cloth component

last fulcrum Sep 20, 2019, 8:28 PM

#

I am having... the most difficulty. With the simplest physics equations.

#

It is genuinely stunning what I have managed to fail into.

#

Here's the sitch: I'm playing ping pong. I want my enemy to intercept the ball.

#

Along the X axis, sliding along their side of the table.

#

So you think, okay, this'll take me five seconds.

#

Calculate the distance along the z axis (forward to the table) from the paddle to the ball.
Divide that by the ball's z velocity (distance/speed = time) to get the length of time the ball will take to travel to the paddle.
Multiply the time value by the ball's (unchanging) x velocity, add the ball's current x position(x0 + vt + at = x1, no acceleration along this axis)), and you have where, on the x axis, the ball will be by the time it hits the paddle

#

Awesome. So you have your game plan, and you feel a little confident. Nay, cocky even. And you get your enemy position, ball position, and ball velocity relative to the table, and you verify that all the values are correct, and you're going this is gonna be easy peasy.

#

Little do you know, you're in for the most nightmarishly boring two hours of your life.

#

This is literally all the code you write, and it doesn't work:

#


Vector3 targetPos = Vector3.zero;
...
// NOTE: This gameObject has no rotation, its x and y local positions are zeroed out, and its parent is the table.
void UpdatePaddlePosition(Vector3 globalBallPos, Vector3 ballVel)
{
    Vector3 localizedBallPos = table.InverseTransformPoint(globalBallPos);
    Vector3 localizedBallVel = table.InverseTransformDirection(ballVel);
          
    if (localizedBallVel.z > 0 && localizedBallPos.z < transform.localPosition.z) // The ball's coming towards us and hasn't passed us
    {
        float zDist = transform.localPosition.z - localizedBallPos.z;
        float t = zDist / localizedBallVel.z;
        targetPos.x = localizedBallPos.x + (localizedBallVel.x * t);
        targetPos.y = 1.1f;
        paddle.localPosition = targetPos;
    }
}

#

...

#

Okay, and this is where it gets real good

#

You write an entire discord post in the OFFICIAL unity server, in the second person, no less, only to realize while typing it, that in your code, you left a stray "minus" sign which flipped the ball's velocity to be negative, ruining the entire computation!

#

It was just a typo, the entire time.

#

warning: this is now a cautionary tale about hubris, and you don't have to read all of the above

sly violet Sep 20, 2019, 8:44 PM

#

Heh. I took one look at how you set the zDist and got the heebie jeebies.

last fulcrum Sep 20, 2019, 8:44 PM

#

Yep. That's where it was.

#

I'll only be computing this while the ball is traveling a certain direction, so I figured "I can hack it!"

#

I could not.

gilded sparrow Sep 21, 2019, 3:49 AM

#

Hi guys. I'm not really sure what's the deal with Unity PhysX, UnityPhysics, and HavokPhysics.
They're 3 different things, right?

#

Is UnityPhysics reliable enough?

#

I'm making a 2D sidescroller networked, thinking how best to organize the net data, which Physics to use or even just use custom

hollow echo Sep 21, 2019, 3:56 AM

#

If you're not using ECS you only have PhysX (edit: 2D has Box2D)

#

if you're using ECS you only have Unity Physics right now

#

Havok will be out at some point "later this summer"

#

Whatever that means. I'm gonna start saying that and people will just have to figure out which hemisphere I'm talking about

gilded sparrow Sep 21, 2019, 4:07 AM

#

Hmm ok. For 2D sidescroller, neither of the 3 applies?

#

Im considering making custom physics for this 2D, just utilize Raycast2D and they're all kinematics kinda thing

hollow echo Sep 21, 2019, 4:23 AM

#

Unity has 2D physics

#

which is Box2D

torpid prism Sep 21, 2019, 5:19 AM

#

Hi, have anyone else seen abnormal disconnects for configurable joints ? All the spring values are disabled (0) , but it will sometimes appear as if its disconnecting. Also the centre of mass of the rigid body was manually changed.

sly violet Sep 21, 2019, 6:19 AM

#

What do spring values have to do with disconnects?
Anyway, "hard" joints aren't that hard, especially strong forces in general and kinematics/animations in particular can force them apart, in much the same way that a kinematic or animated collider can potentially push a rigidbody right through another collider.

lapis plaza Sep 21, 2019, 7:14 AM

#

https://bintray.com/unity/unity/com.havok.physics/0.1.1-preview

#

Limited License. Subject to the terms and conditions of this Agreement, and payment of the appropriate license fees (if any), Microsoft hereby grants to Licensee a nonexclusive, non-transferable, internal, limited license to evaluate the Product at Licensee's premises only. The Product is provided for internal evaluation, demonstration, prototyping, testing, and/or proof of concept purposes only; no commercial product development work is authorized under this Agreement, whether such developed software is used internally or distributed to end users.

hollow echo Sep 21, 2019, 7:18 AM

#

Do you have time to have a play?

lapis plaza Sep 21, 2019, 7:18 AM

#

📎 unknown.png

#

yes

#

so, it's going to remain free for Unity Personal and Unity Plus apparently

#

wonder what kind of price point they have for Unity Pro on asset store sub

#

also, they are putting asset subs on asset store??

#

I guess it's a thing now then

hollow echo Sep 21, 2019, 7:19 AM

#

apparently so

lapis plaza Sep 21, 2019, 7:21 AM

#

it's curious tho that if it's going to stay free for Personal/Plus, why don't they let us use it commercially yet

#

could be just a limitation on early versions I guess

hollow echo Sep 21, 2019, 7:23 AM

#

Speculating at this point probably doesn't have much of a point 😛

lapis plaza Sep 21, 2019, 7:23 AM

#

# Havok Physics for Unity

Havok Physics offers the fastest, most robust collision detection and physical simulation technology available, which is why it has become the gold standard within the games industry and has been used by more than half of the top selling titles this console generation.

This package brings the power of Havok Physics to Unity's DOTS framework. It builds on top of the [Unity.Physics](https://docs.unity3d.com/Packages/com.unity.physics@latest) package, the C# physics engine written for DOTS by Unity and Havok.```

#

## Features

This package provides a closed source physics simulation backend, using the same Havok Physics engine that powers many industry leading AAA games. This implemention shares the same input and output data formats as Unity.Physics, which means that you can simply swap the simulation backend at any time, without needing to change any of your existing physics assets or code.

Compared to the standard Unity.Physics simulation, Havok.Physics offers:

* Higher **simulation performance** : Havok Physics is a stateful engine, which makes it more performant than Unity.Physics for scenes with significant numbers of rigid bodies, due to automatic sleeping of inactive rigid bodies and other advanced caching techniques (typically 2x or more faster).

* Higher **simulation quality** : Havok Physics is a mature engine which is robust to many use cases. In particular, it offers stable stacking and a solution for smoothing out contact points when rigid bodies slide quickly over each other (known as "welding").

* Deep **profiling and debugging** of physics simulations using the Havok "Visual Debugger" standalone application (available on Windows only).

Note that the simulation behavior will be similiar but not be identical to that of Unity.Physics, so if you have finely tuned your simulation you may need to re-tune it.
You can also opt into or out of additional features specific to this implementation to fine tune it further.```

#

@hollow echo well, will definitely know more after Unite, trying to meet the Havok people there while I'm at there but they also got few physics sessions there

#

and they'll definitely promote this at keynote

#


## Roadmap

This first release is focused on ensuring the core simulation and interoperability with Unity.Physics works well.

What to expect in future versions:

* Optimizations to the per-frame synchronization of Havok Physics with the Unity.Physics world. This is currently a single threaded job which could become a bottleneck in some use cases. We expect to multithread and optimize it further.
 
* More options for trading rigid body quality vs performance. In particular we expect to add a super fast, low quality, type of rigid body designed for secondary effects with large numbers of dynamic objects - such as particle or debris systems that need to interact with the physics world.

* More options for trading joint quality vs performance. For example, an option to solve long chains of joints using a dedicated solver.

* Tools for creating physics assets. For example, a convex decomposition tool designed for producing optimized colliders from arbitrary meshes.```

#

that low resolution brute force thing is interesting

#

I've thought about running these on sepearate scene at lesser solver frequency

placid jewel Sep 21, 2019, 9:48 AM

#

hey guys, I'm rather new to unity and I am having a bit of a problem with rigidbodies. I want to throw X objects into another one and have them sit there once they got their final position. I done the coding for that but the issue is that the bodies never stop moving and jittering

#

I tried iterating over the rigidbodies at hand and set their velocity and angularvelocity to zero when velocity magnitude is under 0.01

#

tried destroying the rigidbodies, tried sleeping them but the jitter doesn't stop

#

any suggestions?

#

put the check in a fixedupdate method but am not sure why the bodies keep moving

placid jewel Sep 21, 2019, 10:18 AM

#

my solution for now is just to wait a bit and then destroy the rigidbody of the lower layers, helps a tad.

stuck bay Sep 21, 2019, 10:41 AM

#

So you throw two objects into each other and once they collide they stop moving and nothing can change their position
or
you throw two objects into each other, they collide and after some time you set it so that they position remains stationary and nothing can change their position?

#

Or something else?

placid jewel Sep 21, 2019, 10:52 AM

#

I kinda have one static object and I throw 500 objects into it and expect them to stop moving at some point

#

not keep jittering

#

I guess it's some sort of precision issue somewhere

#

think of coins falling into a box

stuck bay Sep 21, 2019, 10:56 AM

#

You can give these objects a higher drag and they will stop moving faster

placid jewel Sep 21, 2019, 10:58 AM

#

even with an angular and normal drag of 10 they keep jittering

#

hmm

#

this seemed to have worked somewhat

flint tendon Sep 21, 2019, 11:07 AM

#

Hi, I'm using transform.right = direction to target the cube with the tank. But it rotate in one frame. How can I smooth it ? with quaternion.slerp ? Is there an other way ? thanks (2D)

📎 Capture_decran_2019-09-21_a_13.04.06.png

stuck bay Sep 21, 2019, 1:26 PM

#

@ocean horizon Hi again! Lets continue to speak about joints problem:
After i migrated my project from unity 2018.4.9f1 to 2019.2.5f1 i detected that now joints really trying to be in limited angle BUT: angle can be outside of this limited range and THEN slowly trying to return to limited range... so its looks like:
https://media.giphy.com/media/WQ0Fd6GLxNUcKc0Lon/giphy.gif

Giphy

#

and problem is what ragdoll character falling on ground starting with normal angles... but in process some of body parts can take wrong angle and then slowly return, which looks really wrong. Is it our configuration fault or what?

#

Looks like joints have some rotation power...

uneven shore Sep 21, 2019, 1:55 PM

#

I have a 2d circle character with rigidbody2d component. When I move and jump, sometimes the character(circle) can rotate, and that's fine.
I created a script so that when the character is on the ground and idle, it will rotate back over time.
However, it seems I'm sometimes "stuck" in a rotation; stuck as in I can't seem to rotate the character back.
When that stuck state is happening, I can't rotate the character back no matter what. I even tried disabling the script, pausing the game, rotating the character (which works), and then resuming play, which then makes the character rotate back.
I think it has something to do with the rigidbody2d. Anyone has any idea?

fallow gorge Sep 21, 2019, 3:14 PM

#

@lapis plaza is that on regular staging now?

ocean horizon Sep 21, 2019, 3:58 PM

#

@stuck bay It's impossible to tell you what's wrong from any image. In the end, if you think it's a bug, submit a bug case and send it to me or just send me a test repro and I can look at it. In the end, all Box2D joints are soft and can break constraints depending on the forces involved. You are free to increase the number of solver iterations and not just use the defaults to give more time to the solver to produce a solution. This is much more important as the complexity of the simulation goes up.

lapis plaza Sep 21, 2019, 4:49 PM

#

@fallow gorge regular

#

havent seen new packages on staging registry in a long time

#

I guess they got too popular and now they do private testing instead

#

@fallow gorge just to be clear, it doesnt automatically show on PM, you have to add the package name and version manually to your manifest

sly violet Sep 21, 2019, 4:57 PM

#

@placid jewel "I kinda have one static object and I throw 500 objects into it and expect them to stop moving at some point"
Once you get more than a few objects stacked on one another, the physics system has issues resolving them.

placid jewel Sep 21, 2019, 5:32 PM

#

yeah I figured that. have a few workarounds by removing the collider from the bottom objects since I don't expect them to move anymore

flint tendon Sep 21, 2019, 7:17 PM

#

Hi, does someone know how to find alpha angle red in Quaternion format please ?

📎 71100685_683219732172533_8753745993289170944_n.jpg

frigid pier Sep 21, 2019, 7:31 PM

#

@flint tendon Always look at the helper functions first in type classes in docs https://docs.unity3d.com/ScriptReference/Quaternion.FromToRotation.html

flint tendon Sep 21, 2019, 7:33 PM

#

@frigid pier thanks a lot, I've searched all my afternoon ^^

fallow gorge Sep 22, 2019, 12:43 AM

#

oh i was a fool and using com.unity.havok.physics instead of com.havok.physics

#

Unity Pro : Havok Physics subscription required, available from the Unity Asset Store for $20 per seat per month @lapis plaza seems very reasonable to me, from the havok package docs

fallow gorge Sep 22, 2019, 1:17 AM

#

hohum my main camera stops rendering when i install the havok package

lapis plaza Sep 22, 2019, 4:01 AM

#

@fallow gorge yes, that was on the package description as well

#

edit: oh wait there's a price there

#

also, you mean you don't get rendering in editor or in the build?

#

I noticed that you get just white screen on the actual build if you have havok-package installed

#

I dunno if it's some protection for current trial or something else

#

what is interesting is that they said the sub will be on asset store itself

#

there hasn't been subscription services on the asset store before

#

and I'm afraid if they make it public service for all, more asset devs will go for it, which I'd totally hate to see myself

#

it only makes sense if we talk about really high cost things, but soon we might see regular $50 assets selling $5/mo subs instead

#

also wonder what kind of terms will they put there for min sub period :p

coral mango Sep 22, 2019, 4:12 AM

#

Not many people have the bargaining position that microsoft has

lapis plaza Sep 22, 2019, 4:12 AM

#

because I could imagine that if you ship a game using Unity Plus terms initially and then need to update it while on Pro, you wouldn't really need it for more than one month at a time

#

surely they can't expect you to keep the sub running as long as the game is on sale etc

#

usually these tools pricing only applies while you dev

coral mango Sep 22, 2019, 4:13 AM

#

can't? eh?

lapis plaza Sep 22, 2019, 4:13 AM

#

if it's a sub

#

well, I guess they can but it would be silly

#

even Unity doesn't do that

#

if your revenues are over 200k and you don't need to use editor anymore, you don't have to go for Unity Pro

coral mango Sep 22, 2019, 4:14 AM

#

I mean, look at what just happened with Adobe's licensing for some technonolgies running out and suddenly they're freaking out and sending letters at people still using software with it in.

lapis plaza Sep 22, 2019, 4:14 AM

#

that's quite different

#

and Adobe's stuff was totally bonkers

#

threatening users who actaully paid for the tool access

#

they totally screwed that one up

#

they should have just patched the offending audio license out from the old version and everyone would have been happy

#

nobody even used that part

#

@fallow gorge in addition to white screen in build, if you read my earlier comments, they also don't allow use in commercial applications yet

fallow gorge Sep 22, 2019, 4:18 AM

#

seems more like a bug, just editor usage now but the sky is the only thing that renders either game or scene view

lapis plaza Sep 22, 2019, 4:18 AM

#

could be totally intentional as I could imagine they don't want bad press for Havok in published game when the integration is in early preview

fallow gorge Sep 22, 2019, 4:19 AM

#

well the ui renders over it

lapis plaza Sep 22, 2019, 4:19 AM

#

oh, so you don't get issues on the build itself but also on editor?

#

yeah, I didn't get issues on editor but I also didn't actually use the package either, only imported it and build was outputting white screen 😄

fallow gorge Sep 22, 2019, 4:20 AM

#

i havent tested build yet, working from a feeble surface pro, i also get other dots errors on doing a build so i havent tried that in a while

lapis plaza Sep 22, 2019, 4:20 AM

#

I've actually been able to build somewhat recent Unity Physics with Entities just fine on IL2CPP even

#

I noticed that some people are having issues with that combo

#

so I guess it depends a lot on what you do with it, my usage is pretty plain and simple

fallow gorge Sep 22, 2019, 4:21 AM

#

not physics per se but with rendering on a build rendermeshes get placed at 0,0,0 - reproduced by the bug report team so im thankful its not just me

lapis plaza Sep 22, 2019, 4:22 AM

#

hmmmm, not sure if I saw that either

#

I recently removed all hybrid rendering but pretty sure it worked on build before it

#

hybrid just breaks with DXR and is pain to maintain with HDRP so just took it out for the time being

#

I somehow doubt they'll even sort the dxr support any time soon for it as it's developed in parallel and is totally experimental thing atm

#

will try to see if I find DOTS people at Unite to give some answers if that's on the table for 2019 LTS

fallow gorge Sep 22, 2019, 4:27 AM

#

i believe it was 19.3b2 or b3 that had the position bug, wasnt present in 19.2

#

weird i get a missing namespace or type when using havok via package manager, prior i downloaded the package from bintray and plopped into the packages folder

#

Library\PackageCache\com.havok.physics@0.1.1-preview\Havok.Physics\HavokCollisionEventsJob.cs(48,43): error CS0246: The type or namespace name 'Velocity' could not be found (are you missing a using directive or an assembly reference?)

lapis plaza Sep 22, 2019, 4:45 AM

#

@fallow gorge make sure you have matching Unity Physics package

#

it requires the very latest one

fallow gorge Sep 22, 2019, 4:45 AM

#

ah thanks, had rolled it back

lapis plaza Sep 22, 2019, 4:46 AM

#

you tried the one they just released?

#

what issues did you have with it?

fallow gorge Sep 22, 2019, 4:46 AM

#

updating right now again

#

did you mean unityphysics or havok?

lapis plaza Sep 22, 2019, 4:47 AM

#

unityphysics

#

there's only one package for havok, no?

#

as a side note, can only imagine the pain Havok has while trying to maintain these two package APIs together

#

you'd think there would be some feats that straight up suffer for being tied to same mold

fallow gorge Sep 22, 2019, 4:51 AM

#

my only issue was i tried it earlier and the camera was messed up but this was via pasting the archive directly into the packages folder from bintray. i guess it shouldnt make a difference but i was getting an hdrp warning about something but maybe it was significant as the camera wasnt properly rendering any gameobjects, only unity ui objects, even when making a new empty scene

#

yeah camera still not working but ui shows. did you have it working in editor run mode?

#

with the gameview?

lapis plaza Sep 22, 2019, 5:04 AM

#

ah, I didn't really enable it from the physics manager even when I tried, so can't tell anymore

#

I just had it listed on packages and it was enough to ruin the build itself

#

or it built fine but didn't render in build anymore

#

didn't have time to investigate it further

fallow gorge Sep 22, 2019, 5:07 AM

#

it doesnt even render from the mini scene view gizmo you get if you have the camera component expanded

fallow gorge Sep 22, 2019, 5:22 AM

#

i hope that if this isnt a bug, that its just some precursor package thing for unite, that the real thing isnt locked down in this way

unborn narwhal Sep 22, 2019, 1:52 PM

#

hello, has anyone used the new Unity.Physics libraries? I'm trying to just make a cube fall, yet can't even do that. 😭 I've put just about every new physics componant there is on the thing.

lapis plaza Sep 22, 2019, 2:24 PM

#

@unborn narwhal you need to use the conversion scripts for it

#

just grab https://github.com/Unity-Technologies/EntityComponentSystemSamples and run the UnityPhysicsSamples -project from it

#

it has plenty of examples

unborn narwhal Sep 22, 2019, 2:25 PM

#

thanks

lapis plaza Sep 22, 2019, 2:26 PM

#

but in the nutshell, you need to use ConvertToEntity for physics objects and also if you want to control the physics parameters, you need to have Physics Step component on the scene

#

@fallow gorge btw, I just tried Havok with those physics samples (just swapped it to use havok instead), it does render for me on the build so no idea what was going on with HDRP (I tested physics sample with 2019.3 and URP now)

unborn narwhal Sep 22, 2019, 6:33 PM

#

Finaly ended up working with Hybrid Renderer installed. How come it isn't part of the Unity.Physics package dependancy? Or am i missing another way of rendering the entities objects?

brave hamlet Sep 22, 2019, 8:23 PM

#

Is there any way I can make stuff collide with the inside of a collider? I'm trying to recreate electrons running through electrical wires. I'm using the particle system and a polygon collider for the wire.

tiny wedge Sep 22, 2019, 9:42 PM

#

wouldn't it be easier to use a collider around the wire instead ?

sly violet Sep 22, 2019, 11:12 PM

#

The simple answer is "no, you can't do that", not directly, anyway. Polygon collider? So it's 2D? I think you'll need to make Edge colliders along the outsides of the wire.

brave hamlet Sep 22, 2019, 11:24 PM

#

alright thanks

ocean horizon Sep 23, 2019, 7:41 AM

#

@brave hamlet Creating your wires using EdgeCollider2D would seem best as indicated above. You could potentially do that procedurally by having verts for the wire then at runtime generating the edge collider edges at a certain radius away from that. Alternately you could continue using PolygonCollider2D but add a CompositeCollider2D set to Outline mode. Composites are generally use to "merge" multiple colliders together but you can use it here as Outline mode will uses edges identical to what's produced using the EdgeCollider2D. Edges don't have any inside and provide double-sided collisions.

coral mango Sep 23, 2019, 8:12 AM

#

I noticed that sprite shape's automatic colliders are kinda terrible when used with open shapes; I've pretty much needed to draw them manually any time I didn't use a closed shape. Is there any way to make it not assume that it is supposed to be a closed shape?

unborn narwhal Sep 23, 2019, 5:03 PM

#

is there any way to freeze rotation of an object with the new physics? I've tried to just SetComponentData() on update with a constant rotation, but that doesn't work.

lapis plaza Sep 24, 2019, 4:36 AM

#

@unborn narwhal you can use Unity Physics without rendering, hence hybrid not needed

#

This is actually what I do myself atm

#

Do note that conversion workflow exists also beyond hybrid renderer

granite vapor Sep 24, 2019, 1:51 PM

#

Yo guys very new to unity and I think this is the best place to ask this, basically im using a raycast2d to register the max Y and min Y, right now the ray hits a static object but in the future these colliders will be moved based on the difficulty. This way i can change the limits on the fly by a simple func call. Anyway the problem is that it's used on a tilemap collider and the hit.point.y returns the y at the center of the tile. This can be worked around by adding or subtracting the scale of the tile but i was wondering if there was a better way to get edge coordinate of a tile

torpid prism Sep 24, 2019, 2:19 PM

#

can i ask here questions about the new ECS physics or is better suited for #archived-dots ?

torpid prism Sep 24, 2019, 3:05 PM

#

is Havok physics a sperate thing ?

#

so there is the classic unity physics that is based on mono behaviours
then there is the new DOTS / ECS (?) physics
does it mean Havok is something else ?

fallow gorge Sep 24, 2019, 3:07 PM

#

Unity physics for dots and havok physics are a collaboration between unity and havok

#

its a replacement for unity physics which is highernperf and has a stateful simulation

#

it also has a subscription price depending on if your unity license/revenue as an organization, if you are on free its free(this is just info ive gleaned from the docs so far)

torpid prism Sep 24, 2019, 3:10 PM

#

so as long as i keep the unity splash screen i have to pay them 0 dollars ?

#

( im ok with that )

fallow gorge Sep 24, 2019, 3:11 PM

#

you can find a little more info in the docs but ithink its tied to the same restriction unity personal is, ie the revenue being under a certain number rather than the splash screen specifically

#

im sure there will be an official anouncement very soon

torpid prism Sep 24, 2019, 3:12 PM

#

i understand, thanks for the info

lapis plaza Sep 24, 2019, 9:26 PM

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@fallow gorge @torpid prism unity petsonal and plus get free havok physics

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Pro users pay 20/seat per month

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It was also verified on todays havok session at unite

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Here is a really unsharp shot

📎 20190924_143550.jpg

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Also one from unity physics session

📎 20190924_133407.jpg

torpid prism Sep 24, 2019, 9:42 PM

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@lapis plaza is that all already available on github ?

lapis plaza Sep 24, 2019, 9:48 PM

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No unless you mean the sample project

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But both havok and dots physics packages are available as package manager packages

torpid prism Sep 24, 2019, 9:50 PM

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so havok is not dots physics after all ?

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( still going thought ecs, gonna just into dots physics after )

lapis plaza Sep 24, 2019, 10:08 PM

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It uses same api

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I mean the integration is using dots, but havok solvers use closed source proprietary tech

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I'd expect that to be manual simd c++ stuff under the hood

fiery lion Sep 25, 2019, 4:29 AM

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Does a lightning bolt require a nearly 1:1 ratio between the amount of protons in the object it hits and the amount of electrons in the bolt itself?
Or is there a certain relative amount of protons to electrons that is required before an object could be considered a target for a bolt?

coral mango Sep 25, 2019, 4:38 AM

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Technically, it is the ground it is hitting. Whatever other objects it contacts along the way are just a shortcut for it.

fiery lion Sep 25, 2019, 3:14 PM

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After doing a bit more research and thought I’ve realized I’ll probably change that part up. Lightning isn’t attracted directly to any one object, i believe it’s just searching around until it’s lucky enough to come into contact with a positively charged object or something along those lines

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Citation needed lol

sly violet Sep 25, 2019, 3:17 PM

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I don't even know where to start with this.
A negative charge is basically just a bunch of electrons hanging out, but a positive charge isn't just a bunch of protons hanging out. Most of the protons will be in larger nuclei, and there's plenty of electrons still there (if you actually manage to strip all the electrons, then there's no molecular bonds, and the substance would explode as plasma), just fewer than the total number of protons.

fiery lion Sep 25, 2019, 6:44 PM

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Ooh, I didn’t know that

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I also just read that most of the electrons in a lightning bolt are expended in the process of ionizing the air to begin with, and that by the time the bolt makes contact with a cluster of protons there’s not much left

coral mango Sep 25, 2019, 7:03 PM

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@fiery lion Basically, think of lightning like it casting out raycasts to try and find the best path. The first step is to send out lots of little ionized paths through the air, trying to find the ground or a path to the ground. Then, when one of those paths finds a quick path to the ground(that is, something sticking out of the ground) all of the remaining feelers go away and everything is pumped down that path.

fiery lion Sep 25, 2019, 10:38 PM

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Yeah I knew that

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What governs the direction the leaders move when they are emitted from the clouds to begin with?

sly violet Sep 25, 2019, 11:51 PM

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Some combination of relative charge and turbulence/chaos. Last I checked, we didn't yet have a really good model for how they work.

fiery lion Sep 26, 2019, 12:18 AM

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Oh, that changes everything. What’s relative charge?

serene jolt Sep 26, 2019, 2:58 AM

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Just re-posting this here, so basically my issue is when making the player jump by hitting space he only jumps sometimes. It's probably an issue with resetting the y vector too 0 when touching the ground but I'd like some help to see if anyone knows a possible fix
https://pastebin.com/261ueuqG
As a note, it only affects the player when they're not moving, if they move the jumping is fine

Pastebin

[C#] using System.Collections; using System.Collections.Generic; ...

stuck bay Sep 26, 2019, 8:47 AM

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Hello, does anyone know what I can do to calculate the needed angle I need to fire at in order to hit a specific vector3 location? I am making a spear throwing type thing for context (Preferably the method would be hilly terrain compatible)

fiery lion Sep 26, 2019, 1:14 PM

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I’m not sure how to actually calculate this, but if you wanted it to be compatible with hilly terrain you could probably make it essentially say “abstract a 2D circle at the center point between me and my target, where one edge is touching me and the opposite edge is touching the target”

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Then have it start with an extremely short circle (not width, height) and check to see if it intersects with terrain, constantly increasing the height until it no longer intersects, then finally throw the spear along the upper half of that circle

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I’m pretty new to a lot of this physics programming stuff, so I’m not exactly sure if that’s the correct way to go about that. Sound good to me though

random basin Sep 26, 2019, 1:21 PM

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@fiery lion If I understood correctly what you are saying, this means that you deform the circle (keep witdth so it always go through player and target) by increasing height. But wouldn't doing so always have the same angle to throw the spear (Vector up I guess) ?

stuck bay Sep 26, 2019, 2:12 PM

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@stuck bay
I'm guessing that the spear has Rigidbody, and gravity affects it?

fiery lion Sep 26, 2019, 3:14 PM

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@random basin no? The spear would follow the circle, so if the circle gets taller then the spear would go higher, therefore different angle

coral mango Sep 26, 2019, 6:08 PM

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@stuck bay https://www.forrestthewoods.com/blog/solving_ballistic_trajectories/

Solving Ballistic Trajectories - ForrestTheWoods

Detailed explanation of 3d math needed to solve video game ballistic trajectories.

stuck bay Sep 26, 2019, 6:25 PM

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Yes @stuck bay

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Then you can quite happily use equations for diagonal throw(trajectory formulas)

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You know the starting position, end positon, mass, gravity

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That way you can change the velocity so that the angle would change with it too

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Higher velocity would mean lower angle

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If that's what you want

blissful shore Sep 26, 2019, 6:31 PM

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@serene jolt - It looks like you're constantly moving the player down, even when grounded, the old CharacterController is notorious for getting stuck at weird velocities.

I suggest you try not applying gravity when grounded. That's how I and a lot of others have solved this sort of issue with platformers in the past

coral mango Sep 26, 2019, 6:43 PM

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Is there a good/correct/not insane way to apply physics2d joints to an animated object, to have wobbly bits and the like?

serene jolt Sep 26, 2019, 8:21 PM

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Any suggestions on how to do that? Sorry I’m still learning allot of unity’s coding featuresp

stuck bay Sep 26, 2019, 8:39 PM

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I may be misunderstanding, @stuck bay but my velocity when I throw is always going to be the same

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And that's fine, I was just saying that if you want to change it then you could do it

mint dock Sep 26, 2019, 10:34 PM

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So I've combed through the Unity docs and still need more info.

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I'm making a hockey game and am trying to sort how to set up the player.

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Using a capsul w/ rigidbody 3d and moving with addforce and torque.

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How would I add a stick to the player? one that I want to be able to move for shots?

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It seems to throw the whole physics of the player off if I make is a child object.

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Also, I'm trying to sort puck physics. I'd like it to simulate a real puck, flying, spinning, sliding, and flipping.

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I've tried a custom mesh, multiple boxes etc. But it still glitches through any stick I try to make.

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Anybody have a great source on 'best practices' when it comes to a more complex physics character etc?

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📎 unknown.png

blissful shore Sep 26, 2019, 10:51 PM

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@serene jolt - What I recommend trying is this:

Make the gravity/y-motion calculation only on the else branch of your ground check, because this line: moveDirection.y = moveDirection.y + (gravityScale * Physics.gravity.y * Time.deltaTime); is still applying gravity every update, even if moveDirection.y is zeroed from being grounded.

serene jolt Sep 26, 2019, 11:17 PM

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Thank you

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It worked, thank you for the tips

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I really appreciate it

chrome sandal Sep 27, 2019, 12:01 AM

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Hello, how can i detect collision at dots physics package?

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I found ray cast on google , ok i can do it with ray cast but is there any other way?

coral mango Sep 27, 2019, 1:39 AM

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So I had a kinda weird idea. I've seen people use colors as motion vectors for various stuff, would I be able to, say, sample a color image and apply whatever vector color at a given point to whatever 2d rigidbody is there as a force?

gilded sparrow Sep 27, 2019, 2:27 AM

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Yes can

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It can be used like, a "atmosphere grid" determining their particle air flow. Then each pixel coordinate will affect world coords rb2d with that value

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But i would try 2d of that first bcoz 3d means u gotta have a 3d texture and thats kinda heavy(like to update realtime) and harder to see

coral mango Sep 27, 2019, 2:31 AM

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It would be a 2d texture, yes.

gilded sparrow Sep 27, 2019, 2:33 AM

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Its an effort i had long time ago and i did use rb2ds as each air/water vapor particle but looking back, i would use cpu particles with callbacks.

stuck bay Sep 27, 2019, 6:37 AM

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@stuck bay Do you have any other resources? This is a bit above my mathematical skill level

random basin Sep 27, 2019, 7:07 AM

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@stuck bay I'm affraid that you still need some ground mathematical skill if you want a balistic behavior. But i'm sure that if you read it carefully and do some googling for other tutorial about balistic, you would successfully implement it in your game

chrome sandal Sep 27, 2019, 7:08 AM

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Guys, do you have any idea about collision?

coral mango Sep 27, 2019, 7:12 AM

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Lots of ideas, but unless you have a specific question...?

chrome sandal Sep 27, 2019, 7:14 AM

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@coral mango me?

coral mango Sep 27, 2019, 7:15 AM

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Mhm.

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Nobody can really help if you don't ask what you need?

chrome sandal Sep 27, 2019, 7:16 AM

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how can i detect collision at dots physics package?

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Or trigger enter

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Nice i think this typing notification is my answer

coral mango Sep 27, 2019, 7:18 AM

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Ah, ok. Dots is something I haven't even looked at, but good luck!

stuck bay Sep 27, 2019, 7:19 AM

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@stuck bay
The distance that the projectile is going to travel equals [ (initial speed * initial speed) / gravity ] * sin(2 α)
Where α is the angle between velocity vector and the ground
What you want to do is convert the distance between vectors into a float, calculate the angle from that equation, rotate the projectile by that angle and change the local velocity of the projectile

random basin Sep 27, 2019, 7:20 AM

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@chrome sandal Try to ask in the entity-component-system topic

stuck bay Sep 27, 2019, 7:37 AM

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How would I be able to know the distance it will travel if I don't know the angle I am going to fire at?

random basin Sep 27, 2019, 8:08 AM

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@stuck bay From you question, you wanted to know how to compute the angle for a given point in space. So you can easily compute the distance between this point in space and your player

stuck bay Sep 27, 2019, 8:15 AM

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Yes but how? I am pretty sure the equation he posted would only help once I actually have the angle I need to fire

coral mango Sep 27, 2019, 8:23 AM

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@stuck bay did you look at the thing I linked earlier? it had the full sourcecode and stuff

stuck bay Sep 27, 2019, 8:26 AM

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Yeah I tried but I couldn't get it to work with what I am using it for

coral mango Sep 27, 2019, 8:42 AM

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ah well

stuck bay Sep 27, 2019, 9:04 AM

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@stuck bay
But you have to calculate the angle from that equation
That's the only thing in it that you don't know

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I may be misunderstanding but the equation you posted calculates the distance the spear will travel right?

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Yes
And from it you can get the angle

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But the equation needs the angle to calculate the distance in the first place right?

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What? No, you know the start point and end point which are Vectors 3
From them you calculate the distance

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But you said [ (initial speed * initial speed) / gravity ] * sin(2 α) Where α is the angle between velocity vector and the ground

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Yes, and?

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You have the start point and end point, from them you calculate the distance
Then you put that value into that equation

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You also know the speed

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And the gravity

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Therefore the only thing you don't know is the angle

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But the equation I need to calculate the angle needs the angle?

stuck bay Sep 27, 2019, 9:41 AM

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No? Why would it
It's basically like 5 = 2 *x but more complex

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I think we may be confusing eachother, what is the equation you are saying calculates the angle I need?

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I didn't give you the equation that calculates the angle
I gave you the equation from which you can calculate the angle

fiery lion Sep 27, 2019, 3:12 PM

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I’m back with a lightning question because I feel like I’m reading/understanding two opposite things from different articles that can’t both be happening lol

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When an electric field is charged with enough electricity (I.e. clouds for a lightning strike) do they generate stepped leaders that travel in every direction

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Or does the electric field somehow know the general direction of an oppositely-charged field and all of its leaders attempt to go in that direction?

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I understand how air ionization and stuff works and what role it plays in the seemingly-random shape of a bolt/leader. I just don’t understand if the leaders are all traveling in all directions out from the field, or if they’re already automatically drawn toward a possible target the moment they are formed

sly violet Sep 27, 2019, 4:42 PM

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My understanding is that it's a mix. They trend towards the opposite charge, but it's messy and chaotic.

coral mango Sep 27, 2019, 6:33 PM

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watch a high speed video of lightning- you can see the leaders in all directions

fiery lion Sep 27, 2019, 8:25 PM

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What makes the leaders inherently know to “trend” toward the opposite charge 🤔

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@coral mango I’ve seen a few high speed videos and as far as I’ve seen they appear to all go relatively down to some extent

lyric storm Sep 27, 2019, 8:26 PM

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I'm looking at my options for how to best do realistic physics for a wheeled vehicle along a predefined path, like a spline. I have a spline solution but I'm having trouble figuring out how to best do the realistic physics for the wheeled vehicles themselves. Any suggestions to try?
I'm not sure whether I should try writing my own physics for how it behaves when you accelerate and decelerate and when it collides or pulls things along the spline or if there's a good way to work WheelCollider or even DOTS physics into it. I'm also super new to any kind of physics so my mind kind of fries when I try to think of trying to roll my own.

pliant niche Sep 27, 2019, 8:27 PM

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@fiery lion imagine a vector field... each successive point biasing the charge in that direction

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if the air is your vector field then each point in the air is a particle with a charge.. the change in value of the charge from any one point to any other point becomes a direction vector with magnitude. Don't mistaken the real world with simulations.. leaders don't know to "trend" anywhere.. they just move where they need to... the trend is us as humans viewing and analyzing the result in someway that helps us simplify it for our minds.

Imagine a glass jar. Inside it is a vacuum. If you open it up, the gasses outside of the jar will fill it, that "trend" is just each particle reacting to every other particle (we can simplify that to each particle reacting to every other NEARBY particle). They move into the jar because the particles/gas outside of the jar is compressed moreso than that of what's inside of the jar (which is nothing)... the ones near the opening basically get pushed inside by the ones behind it.. and the ones behind those push on them and so on.. until it fills with the gas and the entire space is now UBER slightly lowered in pressure since a tiny part of it has filled the void that was once the jar.

Same goes for your lightning... but now imagine it with charge... aka electron affinity/flow. Rather than a jar being opened.. its more like the jar's lid getting thinner and thinner... until its so thin the gas wanting to get inside the jar just breaks through the lid because its pressure/force on said lid is stronger than the lid itself... Your force is the difference in charge... and the lid breaking is that electron jump (aka spark) add each spark to another and you get a "trend" of a leader... which naturally goes downward.. toward ground.

lyric storm Sep 27, 2019, 8:33 PM

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The self-rolled physics would probably be a sort of abstraction of calculating "real" physics, i.e. some formula to figure out with how much torque does it start to add speed to its movement along the spline given the mass that has to be moved or pulled.

coral mango Sep 27, 2019, 8:59 PM

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@fiery lion It is worth noting that the tip of the stepped leader does not sense the actual charges on the ground as it emerges from the cloud. Rather, as it moves out of the cloud, the stepped leader only senses charges within about 50 meters of the leader tip. As a result, the stepped leader and surges ahead in 50 meter segments based solely on the charges in the air immediate surrounding the tip. Each surge of the leader produces a small flash of light which can be detected by high speed cameras.

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From NOAA.

fiery lion Sep 27, 2019, 9:12 PM

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That is beautiful

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And exactly what I needed

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Thank you so much

fiery lion Sep 28, 2019, 12:05 AM

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I wonder if those 50 meters also match the size of the EMP (I think it’s an emp?) that ionizes the air 🤔

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My god this website quantifies so much. You’ve just made my weekend @coral mango!

mighty sluice Sep 28, 2019, 12:11 AM

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is there a way to get the linear and rotational force vectors that are acting on a rigid body at a given moment?

sly violet Sep 28, 2019, 2:44 AM

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I don't think so. You can derive the net from the change in velocities. That's not exactly the same thing, though - for instance, a rigidbody being squashed could be the same as one with no forces acting on it.

mighty sluice Sep 28, 2019, 3:06 AM

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aye

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that's precisely the thing lol

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i did find something very lucrative though: configurable joints measure some of these forces to determine when and if they break

coral mango Sep 28, 2019, 9:46 AM

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@mighty sluice oh? So can you read that?

mighty sluice Sep 28, 2019, 9:46 AM

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yep. it's currentForce and currentTorque

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it even gives you the vector3 format so you can get axonal magnitude and direction

coral mango Sep 28, 2019, 9:47 AM

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neat

mighty sluice Sep 28, 2019, 9:47 AM

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#DeamComeTrue

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im making complicated "senses" for a machine learning agent

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and this works a treat

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next up is equilibrioception

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balance and g force type stuff....

mighty sluice Sep 28, 2019, 8:20 PM

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Here's the project im working on. Getting the body to behave with approximate 'spider physics' has been an unending adventure

📎 speedcontrolnew.gif

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mostly the unity physics is decent though

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the major comprises made are over-writing the inertia and rotational tensors of the limbs

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because configurable joints strung together create massive instabilities

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making this spider's stability nothing short of miraculous

analog leaf Sep 28, 2019, 9:34 PM

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looks realistic indeed

mighty sluice Sep 28, 2019, 9:52 PM

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the actual movements are still being "machine learned", and overall it is still very much a W.I.P, but im pretty happy with the actual physics aspect of the ragdoll

coral mango Sep 28, 2019, 9:56 PM

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Coool

flint tendon Sep 29, 2019, 10:03 AM

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Hi, I'm experiment Vector2.dot(). WOrking well, but I don't understand why result is 0.70 when I've got a 45° angle between my two vector2. For me it must be 0.5 no ? Thanks (my two vector are normalized with normalise(); )

hollow echo Sep 29, 2019, 10:10 AM

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@flint tendon Dot is not the normalised percentage between two directions, it's the length of the projection of one onto another.

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📎 unknown.png

flint tendon Sep 29, 2019, 12:46 PM

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@hollow echo thanks 🙂

quick tusk Sep 29, 2019, 3:15 PM

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so i was told i could create a 2d softbody like this

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📎 sof.png

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black are points with small coliders and rigidbodies

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and red are springs

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but id just end up with a flat pile

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and no messing with values fixed it

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📎 sof23.png

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This however, did work.

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Now if i want to get more complex than a cube, i run into a bit of a problem.

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this is a lot of springs

📎 sof4.png

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and it takes a hell of a long time to set up

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now think about how many springs youd need for this

📎 sof5.png

mild hull Sep 29, 2019, 7:14 PM

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how should i approach creating a path for a boomerang where its origin (the players position) is dynamic? I've looked into bezier curves and updating position each frame with a parabolas. Should I consider unity physics? This is in a 2d space.

chrome sandal Sep 29, 2019, 8:18 PM

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hello, how can i simulate explosion force at dots physic, i need formula to calculate velocity of each entity.

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ok i found that

lapis plaza Sep 30, 2019, 4:19 AM

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you can stick to triangle patterns

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@quick tusk

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but 4+ verts will never work for that type of thing

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for the circle shape, you'd just have wedges from the middle to the outer side

quick tusk Sep 30, 2019, 4:21 AM

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I got something actually that works well

lapis plaza Sep 30, 2019, 4:22 AM

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this is how rigs of rods, beamng etc do it on 3D: https://imag.malavida.com/mvimgbig/download-fs/rigs-of-rods-6709-3.jpg

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basically you'd have to first figure out which parts are mean to flex and what not, on the tire example, the center of the wheel is solid, so if you need that, you have to do the springs to the middle (as there the other side doesn't directly affect the opposing side), you can do them across the whole diameter too if you don't need the solid part in the middle

timber prawn Sep 30, 2019, 10:56 AM

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I'm trying to make my spaceship hover at a set distance of 1m. Kind of bobs around when hovering, and flies upwards to begin with unless I disable the code until it touches the ground. Also behaves strangely at edge of the ground (flies off). How can I fix this? https://pastebin.com/jQSqajtX

Pastebin

[C#] using UnityEngine; using System.Collections; using System.C...

lapis plaza Sep 30, 2019, 10:57 AM

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you need damping if you want to stabilize that

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you can use regular spring equation for your force

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this doesn't let you specifically set the hoverheight but you can tune it to be in the ballpark you want, right now you just use HoverHeight to limit the max range, not to set the actual hovering height

timber prawn Sep 30, 2019, 11:01 AM

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@lapis plaza sorry I'm new to Unity, what is the spring equation?

lapis plaza Sep 30, 2019, 11:01 AM

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that's not something unity specific but how physics work

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you can read more about this on this archived page: http://vodacek.zvb.cz/archiv/683.html

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but in the nutshell, just this part is fine: ```spring-damper system can be modeled as follows:

F = - kx - bv

Where x is the vector displacement of the end of the spring from it’s equilibrium position, and k is a constant describing the tightness of the spring. Larger values of k mean that the spring is tighter and will therefore stretch less per unit of force, smaller values mean the spring is looser and will stretch further.

Where b is the coefficient of damping and v is the relative velocity between the two points connected by the spring. Larger values for b increase the amount of damping so the object will come to rest more quickly.```

timber prawn Sep 30, 2019, 11:03 AM

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Is this like some sort of PID controller?

lapis plaza Sep 30, 2019, 11:04 AM

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nah

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just spring and damper

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pid would actually let you try to reach some value

timber prawn Sep 30, 2019, 11:05 AM

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Okay thanks. Do you know of a way to fix the other issues too?

lapis plaza Sep 30, 2019, 11:05 AM

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no idea what issues you are referring to

timber prawn Sep 30, 2019, 11:06 AM

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If I don't disable my hover script at game start, the ship flies upwards for some reason

lapis plaza Sep 30, 2019, 11:07 AM

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is it overlapping some geometry at the beginning?

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or is there other scripts giving forces to it?

timber prawn Sep 30, 2019, 11:08 AM

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only one with forces and no overlaps

lapis plaza Sep 30, 2019, 11:08 AM

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well, then look at the script that does do the forces

timber prawn Sep 30, 2019, 11:14 AM

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I sent it on the pastebin thing but I can't tell why it does it

vital rover Sep 30, 2019, 1:17 PM

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Why is this tiny cube still being triggered both during OnMouseDown() (which is not in the script but was before) and with a manual raycast from screen at mouse position etc, even though its layer is ignoring raycasts and is clearly tinier than the blue cubes, the blues cubes are parented to the tiny cube and have colliders, and the tiny cube has a rigid body, is the rigid body adding a collider to children too?

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https://cdn.discordapp.com/attachments/401076282869415946/628214916817354762/unknown.png

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https://cdn.discordapp.com/attachments/401076282869415946/628215013923880960/unknown.png

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dont mind my ugly color scheme, wip

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Im trying to make these cubes collide (which they do) whilst attached to a parent that has the rigidbody to make it fall etc, I am then trying to find out when I have clicked the children object so I can do something with them, but every way ive tried i cannot get the result i need. I either am able to click them but no physics, or physics but cant click them I end up just clicking the tiny cube

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im stumped beyond belief I have tried everything :/

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Im off to bed ive been at this all night, if you know whats wrong or have a decent way of getting around this, DM me as ill most likely not find the ping in here lol

drifting wind Oct 1, 2019, 12:12 PM

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Hi everyone, can someone just confirm something for me? I'm currently calculating the velocity of an object in my scene. csharp var velocity = (oldPos - transform.position) / Time.deltaTime; Then I get the magnitude of that vector. Would that magnitude be the speed in m/s?

random basin Oct 1, 2019, 12:32 PM

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@drifting wind Unit in Unity is meter for world vector position, and Time.deltaTime is in second, so you have ([m] - [m])/[s] , so yes it is in m/s

drifting wind Oct 1, 2019, 12:33 PM

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@random basin Perfect, thank you very much. :)

light temple Oct 2, 2019, 6:41 PM

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Hi, I have a character (rigidbody) you can move. It has an item attached to it, which you can move independently (rigidbody). Both need to be rigidbodies to correctly interact with physics. Parenting rigidbodies is a no-no, and joints are not the intended behaviour. Are there any other approaches to this?

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I'll happily PayPal $10 to the person that leads me to a solution (if that's allowed)

wheat verge Oct 2, 2019, 7:55 PM

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@light temple Solution for what problem exactly?

light temple Oct 2, 2019, 7:56 PM

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Being able to move the character and rotate the attached gameobject whilst both have rigidbodies (to interact with physics)

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It sounds super simple but I've been breaking my head over this the last two days