#⚛️┃physics

1 messages · Page 70 of 1

mighty sluice
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hopefully this stuff makes it to demo soon... I'm investigating some of the final features that i'm interested in (like the sticky fingers for hands and centipede feets), but other than that the core stuff is good enough to ship

arctic marsh
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Dang you are making some fancy stuff there, hope to meet you at some meetup or online unity thing one day, see your stuff featured 🙂

mighty sluice
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hopefully some day 🙂

halcyon prairie
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Hi. When you do a circlecast, and you do it from the playerposition, it detects the Player collider. How do you tell it to ignore that, or access the another trigger?

arctic marsh
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You are making some unique stuff there, I am sure something great will result

arctic marsh
mighty sluice
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my ultimate goal is in machine learning; dynamic and complex environments like this, and real-esque animal bodies and senses, seem necessary for making any kind of animal-like AI. Current researchers mostly focus on making human-like AI, but nobody can even make a centipede or spider AI... that's where I come in 😄 @arctic marsh

arctic marsh
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HAha sounds good! Looking forward to your stuff you are making

halcyon prairie
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Any suggestions on which to check/uncheck?

Screenshot_2021-06-27_132431.jpg
arctic marsh
halcyon prairie
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make a layer for the player...ok

mighty sluice
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i think a layer-mask is what you need

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make the player layer, and then use a layer mask to specify it in the raycast

halcyon prairie
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ok. I guess I need to learn raycasting stuff

mighty sluice
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layer masks seem strange at first but they're really simple. definitely learn a bit about the best way to use layers and layer masks

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they're used for a crap ton of stuff

halcyon prairie
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im going to bings watch something about it then

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thats my week planned

mighty sluice
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it's not that complex lol xD

halcyon prairie
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It effin always is

mighty sluice
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as long as you're not a total c# novice, you'll do fine

arctic marsh
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put your things you want to check on collision on a layer, put your palyer on another layer, do the circlecast with an example code showing you how to layerMask it

halcyon prairie
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the more info the better

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but what is actually happening

mighty sluice
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a layer mask is like a bit value that contains booleans about which layers to detect or ignore

halcyon prairie
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ok

mighty sluice
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so the raycast can ignore what you define via layers and layer masks

halcyon prairie
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how do make a layer mask?

mighty sluice
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this is basically an exact walkthrough of what you need

halcyon prairie
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ok.

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Thanks for your help.

mighty sluice
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np

subtle current
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PhysicsScene.OverlapSphere seems not to work when one of the coordinates are negative

supple sparrow
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It should. Your problem might be elsewhere

timid dove
subtle current
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No

timid dove
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works fine. If you're not sure, share your code we can figure it out

subtle current
# 
 public void PerformMeleeCast(ServerChampion attacker)
        {
            Debug.Log("Attack");
            int layerMask = 1 << 3;
            float attackRadius = 20f;
            int collisions = physicsScene.OverlapSphere(attacker.transform.localPosition, attackRadius, hitColliders, layerMask, QueryTriggerInteraction.Ignore);
            Debug.Log(collisions);
            Debug.Log(attacker.transform.localPosition);
            for (int i = 0; i < collisions; i++)
            {
                if (hitColliders[i].transform.CompareTag("Player"))
                {
                    Debug.Log("Hit");
                    hitColliders[i].transform.GetComponent<ServerPlayer>().TakeDamage(20);
                }
            }
        }```
timid dove
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OverlapSphere expects a world space position

subtle current
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@timid dove Changed it to attacker.transform.position

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and it didn't solve it

lapis plaza
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@mighty sluice I dunno if this is still relevant but if it nearly works and you are fine with having larger contact offset, you could just widen the range where it finds the collision pair by setting bigger global contact offset from your unity project settings->physics

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so, that's even better

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basically you can use that to trigger the collision even when the objects are bit further away, in other words, you can keep you contact modification logic live at higher separation

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@mighty sluice you can also play with setting pair.SetBounciness to 0 (to reduce the jitter if you still have inner collider), and using pair.SetTargetVelocity to always follow the finger's direction (you shouldn't even need the inner collider with this approach)

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although that's not fully sticky, more like attractor kinda thing. could also do pair.SetDynamicFriction to 1 to enforce the max friction to keep the thing in place

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could also play with separation and point value I suppose

mighty sluice
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@lapis plaza the offset trick sounds like it's definitely going to help (even if it only saves me the hassle of an interior collider). But what do you mean by "follow the finger's direction"? Do you mean the direction from the collision point to the finger rigidbody position?

lapis plaza
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yes

lusty hamlet
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when using Rigidbody Interpolation in unity, what goes on behind the scenes? does anything happen in the Physics engine or is this setting only for extra computations during rendering

mighty sluice
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I was trying to think of how to use separation and point to help with the effect (i did try centering the contact point between the two colliders, which was interesting and working-ish, but i dont know enough to really visualize what is happening for separation stuff

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i dont comprehend the contact manifold stuff yet

lapis plaza
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@lusty hamletit's a visual thing, it doesn't change the physics simulation

lusty hamlet
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ah so physics will remain the same after using something like interpolation?

lapis plaza
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main purpose is to keep the physics appearing smooth without jitter since physics sim and rendering are async with fixed timestepped physics

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yes

lusty hamlet
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ty, its a setting that was under fire in a games competitive community that i play since they thought it mustve changed something

feral mango
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Do physics events (like OnCollisionEnter) work with a kinematic rigidbody?

lapis plaza
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@lusty hamlet also interpolation basically shows a value from past, it has small lag because it interpolates between two physics steps.. with extrapolation setting it tries to predict where the object will move (so it's in real-time) but extrapolation can push the object further into colliders etc cause more visual artifacts

timid dove
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for OnCollisionEnter

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for OnTriggerEnter the rules are different

mighty sluice
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I'm gonna implement your separation soltion. Thanks very much for the insight!

lusty hamlet
visual wagon
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greetings everyone!
I'm trying to write a modification to the game called Cities: Skylines and I really-really want to use raycasts to determine whether object is visible on screen or not.
But there's no Collider attached to any game objects, therefore Raycast hits are always false.
Is there any workaround? Can I somehow attach collider to the objects close to camera?

supple sparrow
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what* happens instead

subtle current
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@supple sparrow there is 0 collisions found if you move to any place where the x or/and z is a negative number

summer shell
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Hi im new in game dev and looking to learn about softbody physics (i want to make a movable jiggly 3d ball). Is it an advance topic? because i dont want to be overwhelmed.

wide nebula
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It is, and it's not something Unity handles natively.

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You will have to create your own system, or purchase a ready made one off the asset store.

summer shell
mighty sluice
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@lapis plaza managed to improve it, but it requires an internal collider still, because it seems like the normals simply must be modified in order to negave the depenetration portion of the collision resolver https://i.imgur.com/hBx1N9q.mp4

Imgur
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still no rotational friction on it though

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(though it does stay in place well)

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    {
        for (int i = 0; i < pair.contactCount; i++)
        {
            ContactModType colliderModType = ContactModType.None;
            modifiableColliders.TryGetValue(pair.colliderInstanceID, out colliderModType);
            if (colliderModType == ContactModType.Sticky) {
                pair.SetTargetVelocity(i, (pair.position - pair.otherPosition).normalized * maxStickSpeed);
                pair.SetNormal(i, (pair.position - pair.otherPosition).normalized);
                pair.SetPoint(i, pair.otherPosition);
            }
            else
            {
                pair.SetTargetVelocity(i, (pair.otherPosition - pair.position).normalized * maxStickSpeed);
                pair.SetNormal(i, (pair.otherPosition - pair.position).normalized);
                pair.SetPoint(i, pair.position);
            }
            pair.SetDynamicFriction(i, 1f);
            pair.SetStaticFriction(i, 1f);
            pair.SetMaxImpulse(i, maxImpulse / pair.contactCount);
        }

    }``` not quite sure if and how i can make the forces equal and opposite to ensure stability ...
summer shell
outer trellis
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I got a some what solution to my problem for looking for an enemy. Now running a Raycast to check if there is a wall in front so it won't trigger the stuff if there is

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Other issue is now, I need to filter it properly so you can still get the enemy in front of the wall notlikethis

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But hey Progress

lucid gazelle
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I want to move my character around in a top-down 2d game, so right now I have a kinematic rigidbody and I'm using MovePosition

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but how can I make him collide with walls normally? If I tick off kinematic he collides with them but is affected by gravity

timid dove
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just set gravity scale to 0

lucid gazelle
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thats a

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smart idea

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tyty

lucid gazelle
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I'm a noob when it comes to physics but: I have an object with a kinematic rigidbody and a collider set to isTrigger. But I'm not able to have OnTriggerEnter invoked when it passes through any other objects in the scene. Any ideas?

timid dove
lucid gazelle
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Yeah, ones the player and another has a tilemap collider

timid dove
timid dove
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  • Make sure you're not trying to mix 2d and 3d colliders
  • Make sure you're using the correct callback - e.g. OnTriggerEnter2D for 2D
lucid gazelle
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Ohhh I didn’t know there was a separate method

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That would do it ty

mighty sluice
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and the tractor beam gave me ideas for more sticky-finger math

lapis plaza
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@mighty sluice rotation is probably tricky since you have sphere contact. Do you get more than one contact pair? If you do, you could try not resetting the points to same place. In ideal case you would have like 3 pairs which had like flat triangle shape if you drew lines between their points

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If you only got one point, there isnt anywhere as much effect on friction values

mighty sluice
# lapis plaza <@491366660297588737> rotation is probably tricky since you have sphere contact....

not moving the points does make sense. I'll definitely try out some stuff in that direction. I'm using capsule colliders for the finger bones so at most I'm getting 2 points per finger joint ( I should make simple convex mesh colliders with ideal triangles for this...). Now that I understand how i can manipulate normals a bit more robustly, there are a few other I can try to prevent penetration....

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I was also thinking of using zero radius sphere colliders to create a single gripping point (as a sub collider) for each finger bone. I should make simple convex mesh colliders with ideal triangles for this...

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the idea would be that it can enter colliders, and then have a molasses like effect... somehow

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the real tricky part is normals during penetration events

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I need a use case that can act on all types of colliders, but i can specify the finger collider shapes to something specific

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on the other hands, I think that I can make a good enough gripping mechanic without resorting to the contact mod system, simply by using advanced control systems for the hand joints (some of the same principles I apply to my agents to make them work good). The current hand actually works somewhat because of the way it dynamically reduces applied forces when encountering resistance

crystal charm
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Hello everyone! I have a question about rigidbodies and local space translation, and how to resolve velocity when transitioning to a new moving local space.

I have a rigidbody which is a child of a moving transform.

I am about to change that rigidbody's parent to a different moving transform.

I would like to convert the rigidbody's velocity so that the inertia changes believably as it swaps parents.

Imagine if you will that it's a mug on a conveyor belt, and the belt changes from moving in X to moving in Z - it's that kind of change in inertia I want to maintain.

Does anyone have any insight into methods on the Rigidbody component that will allow me to resolve this?

Thanks!

frigid pier
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@crystal charm Dynamic physics objects are independent, doesn't matter who their parent is. You can use friction for them to influence each other or parent and set to kinematic to fix in place.

crystal charm
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@frigid pier That's not quite what I'm seeing - in this clip, when the mug falls into a trigger volume for the 'conveyor belts' it is reparented to a moving transform. As you can see, the mug is moving along with the transforms.

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As one conveyor feeds into the next conveyor, the mug changes direction sharply (because it is idle inside a moving local space)

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So during that handover I wanted to take the mug's velocity (in world space, which will basically match the translation of its parent transform) and convert that to the translation of the new parent's transform.

crystal charm
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For the benefit of others, the solution to this was to use transform.TransformDirection(localSpeed) to take the speed of the old local space into world space, then add this to the rigidbody's velocity, then subtract the speed of the new local space in the same way, and reapply the velocity to the rigidbody. Hope this is useful to someone - if not, feel free to delete my messages 🙂

fathom verge
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Hi everyone, I'm not sure if this belongs here, but I'm looking for a way to make 2D water that reacts with physics. I'm making a game where the environment is a 2D pond. I want the surface of the water to react to the character, such as if the character goes through, you can see the surface tension. I'm fairly new to Unity or game dev in general, so help would be appreciated. I looked everywhere for guides and such, but none of them really go into how it would work.

mighty sluice
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it made the tractor beam be quite good right out of the gate (scaled the normal i generated by 10 to weaken the depen )

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pretty sure i can use negated depenetration for sticky fingers somehow

halcyon prairie
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anyways....2D physics

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seems like I have to order the colliders on my players and objects very carefully

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Do layers effect child game objects?

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and Unity crashes

mighty sluice
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@halcyon prairie it's actually just an oculus quest controller, mainly using the triggers but also the button sensors for the thumb

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the hand is made from physics based joints; it's sort of like a prosthetic...

halcyon prairie
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i see.

mighty sluice
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it looks like my actual fingers cause that's my specialty lol

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animal like locomotion

halcyon prairie
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cool. how do you make it?

mighty sluice
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networks of central pattern generators

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it's sort of complex

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not complicated, but complex

halcyon prairie
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yeah, i can tell .

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what kind of tools do you use, or do you script it yourself?

mighty sluice
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i really enjoy low level coding so everything is done bottom up, except for some absolutely necessary API's (the good stuff like ml-agents!)

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making physics work is mostly about dealing with low level logic/processes though, so it's fitting for me

halcyon prairie
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how low level?

mighty sluice
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understanding the physics solver, or at least some parts of it, is important for advanced physics use

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using the physics engine for things like ragdolls or aesthetic bouncing/friction is one thing, but making it reliable enough to base core game mechanics on is a horse of a different color

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even basic rigidbodies and collisions need to be handled with care, else edge cases will lead to chaos

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layers don't effect child game objects

halcyon prairie
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yeah. I bet this is very nuanced area.

mighty sluice
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sorta nuanced, yea

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it's all low level simple stuff, like linear algebra

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but when you throw 20 different equations into an iterative loop, you get chaos

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figuring it out takes some hands on experience

halcyon prairie
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yeah...i can imagine.

mighty sluice
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leveraging that chaos to get desirably emergent outcomes is the whole game

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leveraging complexity

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it's the best subject, and the worst subject

halcyon prairie
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yeah...because it;s so complex

mighty sluice
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lol yep

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complexity can be defined as that which is difficult to understand

halcyon prairie
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one error...suddenly cascades of errors....re jig!

mighty sluice
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which is an ironic "fuck you" from the universe

halcyon prairie
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Yeah. but when it works...

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Its like the sistne chapel

mighty sluice
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it can indeed be awesome

halcyon prairie
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Ml agents is very intreseting

mighty sluice
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it's why i use Unity

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my agents are really quite something else

halcyon prairie
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what can they do?

mighty sluice
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they can... locomote

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one sec

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creating this and others like it is why i could bust out a physics based VR hand so easily

halcyon prairie
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what is he trying to do...walk?

mighty sluice
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yea he is just learning to walk and navigate

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he has a target out there he can get

halcyon prairie
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are his legs walking?

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with physics

mighty sluice
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yea it uses about 150 rigidbodies, and as many configurable joints

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there is no animation or procedural anything here

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pure physics

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bio-inspired nervous system

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machine learning

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i also do swimming stuff

halcyon prairie
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its very interesting to watch.....but they do things that actual centipedes dont.....like , theyre kinda able to do too much checking of poition

mighty sluice
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what do you mean?

halcyon prairie
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thats amazing...not ngl

halcyon prairie
# mighty sluice what do you mean?

like....they dont consider things like a real animal...or sense the air....its uncanny valleyish yet, but almost there....the snakes look real though

mighty sluice
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yea that centipede is a work in progress; but in so far as the way they sense the world, I actually went to great lengths to create pseudo sensors; they do sense the environment in many different ways, including their own internal state. I even made a smell system for them, but it's not in use at the moment

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centipedes are awesome but not every smart; their brain is distributed throughout their body, and their main activity is hiding, or hunting by following smell gradients

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right now im focused on the locomotion aspect of animal intellgience, but naturally evolving toward more cortical thinking learning architectures is the plan

halcyon prairie
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well, sounds good.

mighty sluice
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a lot of people want to see things like dog or human AI, but it's easy to forget we need to solve the primitive motor control problems before we can actually give them a body

halcyon prairie
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i can imagine this to be the next "quixel"

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i can see people just dumping a box of centipedes into thier game

mighty sluice
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lol

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once we have the compute for it, hell yes

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the future forecast conststs of increasing numbers of virtual centipedes!

halcyon prairie
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and then theyll be coming to you hopefully

mighty sluice
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but realistically, i do think it's the future of not only video game enemies for physics based games, but also one of the main future paths for AI in general

halcyon prairie
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yeah, i think so too.

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just the thing needs to be installed in Unity....

mighty sluice
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lol

halcyon prairie
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thats probably the hardest part

mighty sluice
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haha, unironically, perhaps

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all the VR capability i showed is essentially a latent capability of making high dimensional phsics bodies for my agents

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debugging the physics of a centipede makes a hand look like child's play

halcyon prairie
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Yeah, i can imagine.

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I wonder how this will manifest itself in the market

mighty sluice
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well im hoping to make a pretty big splash in different communities (gaming, neuroscience, robotics, and machine learning)

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and in VR to boot...

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it's my goal to make animal-like embodied popular

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hopefully by offering an entry point and solutions for low level stuff

halcyon prairie
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Yeah...its a good thing to concentrate on. seems like its got a lot of uses in almost everything. I think the bakery shop in japan...you know...?

mighty sluice
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it wont be immediately useful for automation in most cases, but once we use it as a basis for higher level animal-like AI, it has infinite potential

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having the robot chef carry out a procedure is one thing, but having a robot chef (or supervisor) that can do common sense reasoning is another entirely

halcyon prairie
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They got some ML to identify which pastry is being picked .....and now the same company has licensed the tech to find cancer....so things we you learn in ML in Unity can go anywhere.

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as far as i can tell it is all just finding noise patterns

mighty sluice
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only for narrow tasks

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if you know the solution before hand, or enough examples of it, you can stochastically define what to look for

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and then it's just a matter of compute and time

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but broad tasks... like figuring out a solution without ever having seen similar examples, that's the rub of ML

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we want AI that "generalizes" like humans do

halcyon prairie
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yeah...

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thats a very complex AI

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maybe it is an amalgamation AIs

mighty sluice
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it's a hierarchy of systems; the brain can be thought of as partially discrete units, but it's highly complicated

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what we need is to leverage complexity to get the same emergent outcomes while avoiding the messy complication that comes with wetware

halcyon prairie
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wetware is what? flesh and bones?

mighty sluice
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the nervous system/neurons mostly, but the body is also a necessary component of how human intelligence works

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for example, we learn how to do spatial reasoning because we have a body that moves through a spatial world

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(at least in part)

halcyon prairie
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yeah...otherwise we would be dead

mighty sluice
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the things we can smell, the reflexes we're born with, hormones, etc...

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yep

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we have uncountable support structures like that

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enzymes even....

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but i willing to bet that most of this is evolutionary baggage that can be eliminated thanks to idealized code

halcyon prairie
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Yeah...which the ai strictly doesnt need. but because we want it to imitate the physical world...

mighty sluice
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we want AI that can feel fear, but we dont want AI that reflexively pisses itself

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😄

halcyon prairie
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yeah...idealised

mighty sluice
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the important shit is sensory data

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so that includes the environment and body

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which necessitates simulation....

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enter: Unity3d

halcyon prairie
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idealy it wouldnt pis it self...but then...i guess that would make it more realistic. Ithink you need to make your centipedes do it occasionally

mighty sluice
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defacation and urination is already planned because i need it for the smell

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primitive animals rely heavily on smell

halcyon prairie
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wow

mighty sluice
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so i have a whole aerodynamics/thermodynamics/diffusion system for it

halcyon prairie
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wow.

mighty sluice
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it's way way cheaper than eyeballs

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hard-coding a self-soiling mechanic might be on the docket too, but it will require testing (loosely hard coded; i need to train a network to make emotion lie evaluations, and then interpret negative reward anticipation as anxiety)

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i can essentially make the AI inherently like or dislike certain smells

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so it could be a way to dis-incentivize predators

halcyon prairie
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Are you going to make one animal to focus, or makeing general code for all?

mighty sluice
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more like a continuous spectrum of animal types

halcyon prairie
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because I can see that maybe if you have the agent copy the actual animal...

mighty sluice
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a given body type requires a given nervous system, but they're all very very similar

halcyon prairie
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how can you integrate an actual centipedes movement in?

mighty sluice
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even centipedes are similar to vertebrates; they're like a spine with legs

mighty sluice
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check this video out; it's an overview of the approach from one of the few people deep into the topic

halcyon prairie
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Maybe put some dots on the actual centipede....just bear with me...get some centipedes, colour them white with non lethal paint...draw dots..use top down view to record ...then somehow put it in Unity and...magic

mighty sluice
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xD

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that would be a tad too difficult

halcyon prairie
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Yeah. probably too much work

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coding is easier

mighty sluice
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the beauty of the bottom up emergence approach is that i can generate realistic looking stuff without complicated work

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this is the start of training, learning to swim

halcyon prairie
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that looks very good

mighty sluice
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there is no uncanny valley

halcyon prairie
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that looks very natural.

mighty sluice
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once i fine tune an agent, they all do 🙂

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this is one of my favorites

halcyon prairie
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how much do they cost on GPU CPU?

mighty sluice
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it's basically limited by the rigidbody and joint count

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but i could get away with 10 centipedes for decent gaming rigs

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100 fish or more

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depends on what strategies i use to reduce the compute

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low compute is a main advantage of CPG's

halcyon prairie
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whats the rigidbody count limit for a budget pc?

mighty sluice
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the ml-agents brains can also become a bottle neck

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i would keep it under 100, or maybe try to, for something like a mobile game, but it really depends on many factores

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there are ways to sneak in lots more rigidbodies while sacrificing accuracy and other things

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my plan is to try and have no more than 20 agents active at a time for player experiences

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but i can train them in environments with over 100, or multiple parallel environments with over 1000, depending on the agent type

halcyon prairie
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sounds doable..especially with Moores law..

mighty sluice
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but we need to balance this with murphy's law

halcyon prairie
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lol

mighty sluice
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heh

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inb4 anhilliation

halcyon prairie
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K I think I have a handle on layers.

mighty sluice
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xD

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when you set a parent layer, a popup asks if you want to set it for all children too

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be careful about that if you have nuanced layer hierarchy

halcyon prairie
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Yeah..i saw those. I kinda had to do a lot of changing around in my Bolt scripts yesterday...and now...I'm sorta understanding it.

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Thanks for your help . I'm gonna go do some actual work. 👍 👍

mighty sluice
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same lol

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good luck!

halcyon prairie
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How do I detect 2D triggers?

wide nebula
halcyon prairie
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thanks

stuck bay
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got a quick question about cloth sim
I'm trying to mimic a basketball net - using a cylinder shape with a cloth component on it.
It looks and reacts really well when model is at scale(1,1,1) but once I scale downwards the vertices seem to bunch together?
The left image is at scale(0.1, 0.1, 0.1) and the right at scale(1,1,1)

unknown.png
rugged lotus
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Where was a documentation on simulating physics in editor to "settle" rigidbodies; can someone link it?

tough path
rugged lotus
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@tough path think its the second one; thanks

rugged lotus
rough isle
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I have a 2d scenario here where I have a character that needs to wander aimlessly/randomly in a platformer environment. In the near future, the character will need to climb up walls that the player puts in the environment. (If you're familiar with shimeji desktop buddies, that's what I'm trying to accomplish). I wanted to drive this by creating an empty game object that randomly moves to a different location at random intervals, and the character will target that location to wander to.

It works just fine until I turn on gravity. Then the character won't stop bouncing or jittering on the ground, even though it does match the x-coordinate of its target. How can I get it to stay still?

dreamy pollen
#

If I want to rotate a wheel to match the meters/second speed of a vehicle, what would the equation for that look like?

timid dove
#

so the number of rotations = distanceTravelled / wheelCircumference

dreamy pollen
#

Ahh, * wheel diameter. That's the part I was missing. I knew pi was involved somehow

timid dove
#

then obviously rotation angle = numberOfRotations *360

vale dew
#

Im pretty new to this whole unity game designing thing because me and friends just sayed "lets make a game" but ive been stuck all day because i cant seem to get colliders on my platforms and/or players to work and ive been trying my best to search what to do about it and i cant find any solutions maybe due to me not knowing any terms or something around that and came here to see if i could ask for help from people directly

timid dove
#
  • Make sure the moving object has a Rigidbody (make sure it's 2D/3D as necessary)
#
  • Make sure you're moving the object in a physics-friendly way (via its Rigidbody, not via the transform)
vale dew
#

i had the first 2 covered but does it count by using the transform to move it up then playing the game so it can drop?

timid dove
vale dew
#

oh

#

well

#

i wouldnt know because the player would fall through the floor instantly

timid dove
vale dew
#

alright

#

give me a second

timid dove
#

You're using the wrong kind of collider for the floor

#

BoxCollider is a 3D collider

#

You need BoxCollider2D

vale dew
#

and also i when you look at it just know i didnt figure out how to use the tile pallete because i had a hard time using the dropdowns it didnt work like how i was told

vale dew
#

gimme a sec

#

oh my god

#

you're right

#

well

#

now that this prblem do you know how to use tile pallete??

timid dove
#

no idea

vale dew
#

alright appreciate the help man

vast meadow
#

im sorta having a lag issue or something with raycasts

#

someone threw a pissy fit when i screenshotted code so ill copy and paste it

    void FixedUpdate()
    {
        laserLine.SetPosition(0, transform.position);
        RaycastHit hit;
        if (Physics.Raycast(transform.position, transform.forward, out hit, Mathf.Infinity, layerMask))
        {
            laserLine.SetPosition(1, hit.point);
            if (hit.collider.tag == "mirror")
            {
                RaycastHit hit2;
                if (Physics.Raycast(hit.point, Vector3.Reflect(hit.point - transform.position, hit.normal), out hit2, Mathf.Infinity, layerMask))
                {
                    laserLine.SetPosition(2, hit2.point);
                }
            }
            else
            {
                laserLine.SetPosition(2, hit.point);
            }
        }
    }```
#

u can see how the laser is lagging behind despite my high fps

timid dove
#

it only runs as frequently as your fixed timestep is set to

#

You should really just do this in Update()

crystal charm
#

Quick question about particle systems and triggers - setting ParticleSystem.TriggerModule.colliderQueryMode to One should mean that I can access the trigger collider that the particles in this system have interacted with - how do I access that information? All of the public methods in the TriggerModule refer to collision shapes associated with the particle system trigger - https://docs.unity3d.com/ScriptReference/ParticleSystem.TriggerModule.html - which seems to suggest that it has to have been previously set?

mighty sluice
#

@vast meadow use update for this. and use interpolate on rigidbodies that are involved

sand oxide
#

I've got an object with rigidbody component applied to it that keeps shooting off wherever when I press play or move the object

#

could anyone help?

#

I really just want rigid body for the sake of gravity

supple sparrow
#

You might have colliders intersecting. In these cases what often happens is that the physics engine computes that this state is impossible (for example your player can't be inside a wall) and tries to come back to a normal state by pushing away the object, which can lead to satelliting your objects

vast meadow
shut swallow
#

How can i make a cube not rotate around when force is applied, i just want it to move straight without rotating

arctic marsh
#

does it have a rigidbody? @shut swallow

timid dove
#

You can also set constraints on the rotation of the cube, in the Rigidbody inspector.

hollow cloud
#

i'm trying to make a softbody sim using rigidbody circle colliders. the problem is that when i have two of these bodies collide, often times one will go through the other as the colliders are too small? i can increase the collider's size and it works, but that means having less of them, and decreasing the detail of the sim, which i don't want. is there a way to prevent the colliders from passing through each other.

timid dove
#

e.g. default contact offset

#

not sure

hollow cloud
#

alright thanks, i'll look through the settings, though dcf seems correct

hollow cloud
#

changing the dcf didn't do it, but i got rid of the issue by adding in an edge collider. thanks for the help anyway

shut swallow
#

is there a different way?

crimson fern
#

Just wondering at a high level, is procedural animation expensive performance wise, or could you conceivably do an MMO with physics based procedural animation for the player characters?

arctic marsh
#

you could write down what might have to be transfered over the web in a MMO so every players has the right state of every other, that might kill latency to not playable

crimson fern
#

Would be action combat, so i think youre right that it would probably kill the latency to have even a dozen people sending their positioning and stuff like that every frame lol

arctic marsh
#

And also have the collision checks being send, and and and 😄 in a few years, who knows 😄

#

Maybe you come up with something smart to lower the data usage 🙂

timid dove
#

Typically this kind of thing is done with:

  • server runs the main physics sim
  • clients run their own physics sims to look smooth but they will accept the server's state of the world as gospel and readjust themselves
crimson fern
timid dove
#

but having a huge number of animated bones etc. that the client needs to sync from the server can be a lot for

shut swallow
timid dove
timid dove
crimson fern
#

Maybe 200ish logged in at any time, maybe a quarter of that in any concentrated area

timid dove
#

I mean look at TABS for example - that game starts to slog when there's around 50 characters or so

#

active ragdolls are pretty expensive

crimson fern
#

Oh, tabs is a good example actually

#

Yeah

shut swallow
#

i don't want that to happen

#

i want it to just move foward

crimson fern
#

Hmm yeah, probably better to just have the player ragdoll if they get sent flying but otherwise not procedurally animate anything

timid dove
shut swallow
crimson fern
#

Thanks Praetor

timid dove
# shut swallow i think so

i mean I'd definitely say constraints are the way to go. Not sure what your issue with "stopping for half a second" is

shut swallow
timid dove
#

possibly. bug in your code, or something else going on.

shut swallow
#

like it hits a invisible barrier for a half second

shut swallow
#

@timid dove could it be stopping because when it tries to move the constraints blocks it and the motion is lost?

timid dove
#

constraints generally work as an "energy losing" mechanism

#

any energy that would've gone into motion or rotation along that constraint is just lost

#

Maybe try adding a custom physic material to your box's collider

#

with low or no friction

#

(make sure to use "minimum" friction combine method)

shut swallow
#

@timid dove now the when i try to move the object it loses all momentum in the foward direction and just starts going to the side

timid dove
#

and what does your code look like

shut swallow
#

i forgot to remove the constrains

shut swallow
timid dove
shut swallow
# 
using UnityEngine;

public class PlayerMovement : MonoBehaviour
{
    public Rigidbody rb;
    public float forwardForce = 400f;
    public float sideWays = 400f;
    
    void Start()
    {
        
    }

    
    void FixedUpdate()
    {
        rb.AddForce(0, 0, forwardForce*Time.deltaTime);
        if ( Input.GetKey("d") )
        {
            rb.AddForce(sideWays * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
        }
        if (Input.GetKey("a"))
        {
            rb.AddForce(-sideWays * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
        }
        if (rb.position.y < 0){
            enabled = false;
            FindObjectOfType<GameManagerS>().Menu();
        }
    }   
}
timid dove
#

no need for Time.deltaTime with AddForce and FixedUpdate

#

that's why you have to have such a large force value.

shut swallow
#

oh

timid dove
#

I think your main problem is just the interaction of the torques you're going to get from moving diagonally combined with the constraints

shut swallow
#

now it's running at the speed of light

timid dove
#

yeah reduce the forces to something reasonable

#

and/or use the default ForceMode

shut swallow
timid dove
#

ForceMode.VelocityChange is equivalent to just saying:

rb.velocity += myForceVector;
#

ForceMode.Force (the default) is equivalent to:

rb.velocity += (myForceVector / rb.mass) * Time.fixedDeltaTime;```
shut swallow
#

now it looks to be working fine without the random stopping

#

after remove the delta tiem

timid dove
#

ah interesting

shut swallow
#

now it suddenly froze

timid dove
#

🤔

shut swallow
#

unity is working

#

but the game has froze

#

whenever i run it i just stops

timid dove
#

honestly I have no idea what that's about. Maybe you just lost focus ont he game window?

#

what other objects are in the scene?

shut swallow
#

even if i lost focus

#

it should run

#

i have a auto generating ground and auto genratin obstacles

timid dove
#

maybe you're running into some invisible obstacles?

#

any way you can turn off the obstacles compeltely for the moment just for testing?>

shut swallow
#

wait a minute

#

i disabled it

#

@timid dove now there are no problems

#

i was wrong

#

on the third fourth run it hung again

#

@timid dove everything just stops, it looks like the fixed update loop is not happening

timid dove
#

or disabling your objecgt

shut swallow
timid dove
#

I mean you do have this:
cs if (rb.position.y < 0){ enabled = false; FindObjectOfType<GameManagerS>().Menu(); }

#

enabled = false

#

maybe that's triggering?

shut swallow
#

but when this happens a menu also pops up, that doesn't pop up

timid dove
#

maybe the menu part is broken

#

try commenting out the enabled = false

shut swallow
#

if i go of the track intentionally the menu pops up

timid dove
shut swallow
timid dove
#

that or disabling the object/script is the only way FixedUpdate would stop running

shut swallow
#

now i am running it and their is no stopping

#

but how could the function trigger if my object is always on the track

#

also why isn't the menu popping up

timid dove
#

¯_(ツ)_/¯

#

do you have any errors in console?

shut swallow
#

nope

#

it stopped again

#

that is not the problem

#

@timid dove

#

hello

#

@timid dove u there?

summer fog
# shut swallow nope

pinging someone 8 times in a 10 minute conversation is a pretty easy way to scare them off

hollow cloud
#

i have a simple script to stick one rigidbody to another, having this in the OnCollisionEnter2D

if (collision.transform.parent != transform.parent) // check that it's from a different one to not stick to itself
        {
            SpringJoint2D joint = gameObject.AddComponent<SpringJoint2D>();
            joint.frequency = 0;
            joint.dampingRatio = 1;
            joint.connectedBody = collision.rigidbody;
            joint.autoConfigureDistance = false;
        }
#

and it works - the objects stick - however, for whatever reason, other colliders are now ignored

#

and the weirdest part is that the collisions are ignored by totally different colliders

#

i have a bunch of circle colliders joined together with spring joints, put under the same object and give the script to each one of them

timid dove
hollow cloud
#

but the thing is it works fine when the stick script is disabled

timid dove
#

hmmm not sure really.. joints shouldn't really affect collisions afaik

#

they basically just apply forces to your bodies based on the join settings

hollow cloud
#

though just with one it's still the same thing

D2D4617D-13FC-4150-BBBB-783E8C9F6DCB_4_5005_c.jpeg
#

increasing default contact offset doesn't help

runic talon
#

I'm having an issue where OnTriggerStay is not being called in a situation where I expect it to be. My setup is:

 - Sphere A* (child of Cube A, has SphereCollider with isTrigger=true)
Cube B (same as Cube A, sitting underneath cube A and colliding with it)
 - Sphere B (child of Cube B, same as Sphere A*)

Or, if you prefer paint drawings, I've diagrammed my situation below. The script on A is receiving OnTriggerStay events for B*, and other colliders in the scene without Rigidbodies, but is not triggering for B. My understanding of the documentation https://docs.unity3d.com/Manual/CollidersOverview.html is that I have a Rigidbody Trigger Collider A*, and a Rigidbody Collider B, and according to the table at the bottom of that page, these should trigger the OnTriggerStay method.

I must be misunderstanding something and would love someone to point out what I'm missing, thanks!

unknown.png
timid dove
#

Given your setup I'd actually kind of expect... more than one OnTriggerStay to be called each physics update.

#

Somewhere between 2 and 4 of them

runic talon
# 
        Debug.LogError(other.name); // Cube B not showing up unless you change its collider to trigger...
        
        // Do some logic to determine if we should ignore collision with 'other' or not
        ...
    }

This logs multiple times per physics update yes, once for each object with a collider (no rigidbody) nearby in the environment, and once for the other box's trigger sphere, but never for the other cube itself

#

What I would like is for A to detect the overlap of A* and B, and then disable the collision between A & B if certain other conditions are met. Instead, right now A just rests on top of B and I never see OnTriggerStay in the script on A getting called for B

timid dove
#

What if you put a script on A*?

runic talon
#

Hmm since the script on A gets called for the collision between A* and B*, and with knowledge that those two colliders should be the same, I inferred that they were both considered "Rigidbody Trigger Collider", since if they were just considered "Static Trigger Collider", I wouldn't see OnTriggerStay for A*/B* collision.

I can rework the logic to place the script on A* and see what happens

runic talon
#

Same exact behavior when the script is placed on A*...

signal basin
#

Feeling a little stuck trying to debug some crashes I've got going on. I managed to reproduce one on my machine, found the crash.dmp file and opened it in VisualStudio (and loaded symbols). This is what it's showing:

unknown.png
#

(sorry for small text). Essentially looks like the crash is happening inside of physx somewhere. This is the most recent LTS 2020.3 build BTW (2020.3.13f1)

#

Does anyone have advice on where to go from here?

#

actually sorry, these are from builds on 2020.3.10f1

shut swallow
#

Hey, so in my game the player is a square and they have to move through obstacles , to not have the cube rolling like crazy i inserted rotation constraint after doing that for some reason when i am playing the game sometime the cube stops for half a second and sometimes it just stops completely i noticed that if i remove the constrains it starts again

#

how could i do to fix it?

rugged lotus
#

Can someone assist me with my drag force? I implemented the formula (numerous variants of it), but it keeps making the projectile go in reverse. https://cdn.discordapp.com/attachments/763495187787677697/860045618046435358/2021-07-01_09-33-40.webm

public static float AerodynamicDrag(float dragCoefficient, float velocity, float objectRadius, float airDensity = 1.0f)
    {
        float A = Mathf.Pow(objectRadius, 2) * Mathf.PI;//reference area (radius^2 * PI)

        float Fd = dragCoefficient * (airDensity * (velocity * velocity)) / 2 * A;//drag force


        return Fd;
    }

And i use it like this

Vector3 dragForce = GameManager.AerodynamicDrag(projectileStats.dragCoefficient, velocityVector.magnitude, projectileStats.projectileDiameter) * velocityVector.normalized;
Vector3 dragAcceleration = dragForce / projectileStats.projectileMass;
            velocityVector -= dragAcceleration * Time.fixedDeltaTime;
▶ Play video
#

Oh and the input values are:
0.2 , current velocity , 0.0762 with mass 0.0163

timid dove
#

oh nvm I see

#

just the direction

rugged lotus
#

mhm

#

since the formula doesnt implement the vector, just the speed

timid dove
rugged lotus
#

fixed

#

@timid dove oh before you end up doing something; might i add that i'd like to get rid of the A value n the calculations and have mass be correctly factored into the resistance; since the area calculation seems to be quite fiddly and could even bsod the computer if its too large

#

@timid dove oh i should probably give you the current formula:
float Fd = 0.5f * (airDensity * Mathf.Pow(velocity, 2)) * dragCoefficient * A;

#

this one is supposed to be the right one

#

which by the looks of it doesnt really end up with a different value 😄

timid dove
#

didn't you say this was fixed?

rugged lotus
#

what was fixed

timid dove
rugged lotus
#

FixedUpdate eyesShake

timid dove
#

meaning you switched to fixedUpdate or from it?

rugged lotus
#

im using FixedUpdate

timid dove
#

ok good

rugged lotus
#

i never stopped using it or changed from it

timid dove
#

ok you can see how I was confused when you said "fixed" then?

#

Ohhhhh

#

wait

#

wow

#

I'm stupid

#

😅

timid dove
#

but you were just answering my question. 🤦

rugged lotus
#

yeah thonk

#

i should really specify haha

daring furnace
#

I was testing Raycasts and want to confirm some things.
When firing from an object starting from its position, a Physics2D.Raycast would hit the object it started from, but a Physics.Raycast does not?
Just for context, these are the code lines I used

//3d
Physics.Raycast(transform.position, Vector3.right * distance, out RaycastHit hitInfo)
//2d
Physics2D.Raycast(transform.position, Vector2.right, distance)

I see in Physics.Raycast it says "Notes: Raycasts will not detect Colliders for which the Raycast origin is inside the Collider."
https://docs.unity3d.com/ScriptReference/Physics.Raycast.html
and in Physics2D.Raycast it says "this will also detect Collider(s) at the start of the ray"
https://docs.unity3d.com/ScriptReference/Physics2D.Raycast.html

Assuming this is intended behaviour as the docs say(would like confirmation on this, in case I'm using raycasts wrongly), how do people usually avoid the Physics2D.Raycast from returning the object it's fired from, especially if it's starting from transform.position? Is a layermask the usual way of handling this? (Sorry for the roundabout question)

timid dove
#

layermasks probably, yes

#

in rare circumstances where that's not possible, you might do a raycastAll and manually filter out your own object

daring furnace
#

I don't understand this description from Physics2D.Raycast though
"Additionally, this will also detect Collider(s) at the start of the ray. In this case, the ray starts inside the Collider and doesn't intersect the Collider surface. This means that the collision normal cannot be calculated, in which case the returned collision normal is set to the inverse of the ray vector being tested. This can easily be detected because such results are always at a RaycastHit2D fraction of zero."

timid dove
#

But layer mask should always work

daring furnace
#

I thought this meant i'd get a different result if I fired a really short ray that did not exceed my sprite bounds. I don't.

timid dove
#

no it means that it will detect the collision before reaching the bounds

#

it collides at the start point of the ray

daring furnace
#

oh, I see now that the first 2 sentences come hand in hand

#

I guess I dont really understand the collision normal bit though

#

but thank you. I was really stumped on this until I noticed the difference in behaviour between 2d and 3d. kinda odd that it's inconsistent that way

timid dove
#

Anyway there's a bit of a trick that I discovered a little while ago that makes it quite easy to avoid the object you're starting in, even without using an explicit layer mask:

int oldLayer = myCollider.gameObject.layer;
myCollider.gameObject.layer = Physics2D.IgnoreRaycastLayer;
// perform the raycast here
myCollider.gameObject.layer = oldLayer;
daring furnace
#

my goodness. how hacky, haha. thank you! that saves me the trouble of understanding the bitshifting part of layer masks(for now)

#

thank you

timid dove
#

yeah it works so much more nicely than I expected

rugged lotus
#

@timid dove Have you managed to find something?

timid dove
rugged lotus
#

heck

timid dove
#

I think it's 2

daring furnace
#

aw man. that means I need to understand the layers and stuff haha

#

i'll try things out some time. thanks for checking!

timid dove
#

not really - just replace Physics2D.IgnoreRaycastLayer with 2

#

should work 😉

rugged lotus
#

what is ln supposed to be? thonk

unknown.png
timid dove
#

it's the natural logarithm function

rugged lotus
#

how would that go into unity

timid dove
#

in unity you'd do it like...

float e = (float)System.Math.E;
Mathf.Log(someNumber, e);
rugged lotus
#

this formula written seems to be a bit...scuffed

#

man , i see why games dont implement realistic air drag now

timid dove
#

or just use ```cs
System.Math.Log(someNumber);

#

Yeah unless you're writing like a realistic flight simulator or something I'd just use an approximation

rugged lotus
#

no no even in sims they dont seem to do this 😄

#

but yeah i would like an approximation; cant find a good implementation though

#

the terminal velocity also seems to be...wrong

unknown.png
#

unless a projectile indeed only falls at 9.7m/s

#

@timid dove would this be a good "approximation" ? cs Vector3 dragForce = -(Mathf.Pow(velocityVector.magnitude, 2) * velocityVector.normalized) * projectileStats.dragCoefficient; Vector3 dragAcceleration = dragForce / projectileStats.projectileMass;

hollow cloud
#

not sure where to put this, but i'm looking for a way to deform 2d sprites

signal basin
signal basin
rugged lotus
#

im logging Vt

#

@signal basin float Vt = Mathf.Sqrt((2 * projectileStats.projectileMass * projectileStats.gravity.magnitude) / (projectileStats.dragCoefficient * A * 1.225f));

jovial wraith
timid dove
#

or NaNs in settings.maxStoppingAcceleration or settings.maxAcceleration

jovial wraith
timid dove
vast meadow
#

what do i do when collision detection is too slow

#

the 3 logs yousee pop up arefrom lateupdate, ontriggerenter, and ontriggerexit

#

for the diagonal box

#

literally all i can do is change the physics timestep but that makes the game move in slow motion on laggy pcs

#

a physics timestep of .01 isnt even fast enough

rugged lotus
#

How do I make the second check work like the first one? Or is it not possible ```cs
if (!Physics.CapsuleCast(transform.position, transform.position, controller.radius, transform.up, 1.8f, crouchLayerMask))

if (!Physics.CheckCapsule(transform.position, transform.up * 1.8f, controller.radius, crouchLayerMask))

rugged lotus
#

Think i figured it out cs if (!Physics.CheckCapsule(transform.position + transform.up * controller.radius, transform.up * (1.8f - controller.radius), controller.radius, crouchLayerMask))

#

the starting point was touching the ground so it was always true

vast meadow
#

is there any way at all i can use this as a trigger

unknown.png
#

it has to be that shape

#

i cant make it convex

vast meadow
#

nvm i divided it into more basic shapes

mighty sluice
#

the cause is collisions between fingers the the board a a place that has extremely big inertia compared to the fingers

#

the board is being linked to the palm RB (which all of the fingers are anchored to also via configurable joints)

#

I want the fingers to rest and put pressure on the object being held, but during fast movement and with big inertia, the collisions between the fingers and the board get wacky, which causes the solver to spiral into chaos as the board and fingers all mutually depentrate

#

I've tried a lot of things to fix the issue; the one thing I want to avoid is giving the fingers extreme inertia of their own, and it's not exactly desirable to dynamically or bakedly bork the inertia of the wooden boards either.

#

The approach seems to work perfectly for reasonable inertias, but I need to make it robust for as many edge cases as I can.

#

Anyone have suggestions?

#

The reason why I dont want to fuck the fingers too much is because they're actually functional on their own. I can use them without the dynamic grasping joint in order to pick up appropriately sized objects, and they will grip it effectively enough. I can also use them to climb by hooking ledges with finger tips (the forces are just right so you need to go slowly or you will slip/ the fingers will give). They also can move around a bit in response to external forces, which is a good thing for immersion....

#

Right now the only solution I can think of that will work for sure is to completely separate the firm grasping mechanic from the finger clasping mechanic (which is just flexing finger joint motors). I will remove the stiff joint between the hand and grabbed objects, and just create some gravity glove -distance grab mechanic like every other game...

#

if the fingers aren't in contact with the heavy fast moving objects, then no collision related chaos; And if i am using finger clasping only to try and manipulate a heavy object, the fingers and palm alone should not be able to accelerate it to the point that collisions break (it's only the solid joint between the palm and the object being picked up which allows for the unrealistically strong grip

weak peak
#

While using multiple collider to same game object, the mass also get distributed to all colliders ??

mighty sluice
#

they are combined into a compound collier and considered all belonging to the same parental mass

oak thorn
#

Hey, how can I stick together 2 different object when they touch for the first time ? They both have ragdoll. I tried parent-child but it didn't work at all. Should I use OnTriggerEnter method or any different suggestion for this? (I'm new sorry if it's so basic question :'))

shell adder
unkempt vale
#

Hi, does anyone here have a PI controller implementation for velocity control here?

#

Programmer love being the reward ❤️

#

Maybe I just didn't sleep well enough, but I'm absolutely unable to find one...

empty rock
#

Hello !
I don't know if this is the right channel but here is my problem :
I am working with Bolt, and have successfully created a weapon projectile system by setting up a visual script that will create prefab (projectile) instances at precise coordinates And I used the "set velocity" option to move the projectile when I left click, but the problem is that it only works on the first projectile and not on instances, I think I deduced the problem, I could see that when the script creates Instances, these last do not have the "collider" and "rigid body" components of the original projectile, and I think that is why my "set velocity" does not work.
I hope I can get some help to solve this problem which is starting to demotivate me a bit.
thank you in advance !

timid dove
#

If the prefab has Rigidbody and Collider components, the instances should have them too.

empty rock
#

But they don't
when I run the game I see instances created in my hierarchy, and when I select them I do not see these components, is that normal?

timid dove
shell adder
#

if u instantiate a prefab and it has components then it should have those components in the instantiated as well

timid dove
#

Make sure you're instantiating the correct prefab

empty rock
#

I can show you screenshots of the script to verify ?

timid dove
#

sure

#

I've never used Bolt but hopefully I can help

empty rock
timid dove
#

where's the instantiate part

empty rock
#

And this is the gun script that instantiate

unknown.png
timid dove
#

"Original" is pointing to a child object of "GameObject"

#

I'd guess "GameObject" has the rigidbody/collider on it

#

"sphereref" looks like it's just an imported model from blender or whatever

empty rock
timid dove
#

really what you should be dragging into that "Original" slot is the prefab from your project window

#

See that little ">" arrow on "GameObject"?

#

that lets you edit the prefab itself

empty rock
timid dove
#

Ok but when you click on the "sphereref" thing that's in that "original" slot

#

where does that take you

empty rock
#

i don't see what u mean by original slot 😅 srry

timid dove
#

in your bolt graph

empty rock
#

Oh ok

timid dove
#

click on that

#

see where it takes you

#

click on the name "spheref" there

#

whatever that takes you to - that's the thing that will be copied

empty rock
#

it alludes to the prefab "spheref"

timid dove
#

yes and

#

what components are on that

#

when you click it and select it from the "Original" slot

empty rock
#

i can't select that from here but ig it alludes to the prefab which is in my content browser and not that of my hierarchy

#

bc i selected it from the folder where i imported it

timid dove
#

and in your "content browser" (also known as the project window), there is no Collider and no Rigidbody on it, right?

#

because it's just the thing you imported from an external program.

#

That is the thing you are copying

#

and that is why the copies don't have those components

empty rock
#

Ty
i replaced it by a Default unity sphere

timid dove
#

What you need to do is drag the one from your scene into the project folder to create a new prefab that does have those components on it. Then drag that new prefab into your "Original" slot for Instantiate

empty rock
#

and when i open it in the project window it do have these compenents

empty rock
empty rock
timid dove
#

then drag

empty rock
empty rock
#

since the sphere I am using here is exactly the one I am creating instances for I do not understand what is wrong

#

It spawns but the "set velocity" doesn't seem to work on it even though the instances have the RigigBody component now

heavy torrent
#

has anybody an idea what can cause a raycast to completely break by doing from my perspective... nothing?

#

my first thought was that occlusion culling may cull out the ground he is standing on but OC is turned off and it still occures

#

i have another project where the character works just fine (it is an HDRP project but from my knowledge that doesn't affect raycasts 😦 )

#

what bothers me most is that he literally hits nothing

#

and it's not like i use highly complicated scripts. i just made a new one and the problem is still the same

shell adder
# heavy torrent

maybe try to do a Debug.DrawRay to see where it goes and if it hits anything

heavy torrent
#

oh i do that via another script. you can see the little red line in the video

shell adder
#

oh sorry didn't see that yeah

heavy torrent
#

it's red when it hits nothing and magenta when it hits something

#

no problem^^

shell adder
#

what layers do u have?

heavy torrent
#

what bothers me most is that i even disabled the layermask entirely and it literally casts from inside a capsule collider. shouldn't it at least always hit that?

shell adder
#

i don't think it does

#

1st answer

heavy torrent
#

the capsule (from the character) is on layer 19 ("Player") and the terrain is on layer 14 ("Environment")

shell adder
#

if u cast within a collider it will return false

heavy torrent
#

is it "always" false or can that be bypassed by using a layermask?

shell adder
#

it'll detect other colliders just not the one it's cast inside of

#

also i think for raycasts u use fixedupdate?

#

at least in the documentation it does

heavy torrent
#

i think (not sure tho) you can use both. but i can try again

#

nope fixedupdate didn't solve it

shell adder
#

in that case the ray might be cast inside the terrain collider and so it wouldn't detect

heavy torrent
#

what bothers me most is that it is not like "the raycast stops work for the terrain it stand on" No. It breaks entirely, i can walk on other objects with other colliders and other layers and it hits none of them

#

intersection shouldn't be the case, i can jump and fly so they don't intersect and he still doesn't hit anything

shell adder
#

oh

heavy torrent
#

the ray has a 30 unit range which should be far enough to not intersect^^

#

hmm can this be a new bug in 2020.3?

shell adder
#

i don't know it could be a bug

heavy torrent
#

the other hdrp project where i copied the character from is still on 2020.1 and it works just fine

shell adder
#

do u have any rigidbodies attached?

heavy torrent
#

i use the original character controller from unity

#

so no :/

shell adder
#

i don't know sorry

#

i'd say restart unity to see if it still persists

heavy torrent
#

oh good idea

#

maybe its just unity hiccups

#

nope didn't fix it 😦

shell adder
#

damn

#

sorry i couldn't help

heavy torrent
#

thanks nonetheless you tried^^

#

i wish i would at least barely understand why it keep breaking

#

like how can camera orbiting stop a raycast from working thats soooo weird

empty rock
#

Thanks anyway

heavy torrent
#

ok now i am completely confused

#

i found a spot where it works and where it doesn't work

#

there is literally 0 difference in the two spots

#

ok there IS a difference

#

so: everything is fine. i then rotate the camera around till "something" happens which breaks the raycast so it hits nothing anymore. now it doesn't work UNTIL i reach a point on the map where ALL Transform position values are Positive. when X or Z reaches a negative value. it immediatly breaks again even when standing on the same terrain

shell adder
#

oh i think maybe try to use transform.down not vector3.down

#

because transform.down is relative to the player character

heavy torrent
#

Transform.down doesn't exist

shell adder
#

i meant -transform.up sorry

heavy torrent
#

i never ever used that. always used vector3.down but i can try it

#

that wasn't iit

shell adder
#

damn

heavy torrent
#

ok the raycast only breaks when in negative position

#

i can rotate the cam around nothing bad happens but as soon as i afterwards enter negative space it immediatle hits nothing

#

that doesn't seem like I am just a dumb programmer anymore

#

i mean, i now know how to fix it. i just have to move my entire scene into positive space but i mean, that well that does sounds like an issue

#

unity shouldn't do that

#

here is a video that shows it (the white "ground" is just there to visualise the positive space, it has no collider or relevant layer)

timid dove
#

And what is assigned to "col1" in the inspector?

heavy torrent
#

right now coll uses exactly this capsule collider

timid dove
#

So theoretically col1.transform and transform should be the same, yes?

heavy torrent
#

yes

serene orbit
#

Hi guys, is there any way to detect overlap of colliders in editor mode ?
I am writing an editor script to generate a city. But to check overlap between buildings the OverlapBox does not work in the editor.

heavy torrent
#

@serene orbit does OnCollisionEnter not do the work?

serene orbit
#

Nope, I have been trying with OnOverlapSphere and OnOverlapBox. Does the OnCollisionEnter work in editor mode if the play mode is not active ?

#

Some forums people say Unity does not run physics by default in editor mode, so thought if anybody had this usecase before ?

heavy torrent
#

i can't tell for sure if it works or not but it would be worth a try

serene orbit
#

Yeah sure, I have to try it now then. Thanks!

heavy torrent
#

but i am not a real programmer so i can't tell if this is helpful

serene orbit
#

Bounds class should work in editor I think. I will try with it.

serene orbit
#

@heavy torrent Finally it worked. I had to use a Editor Coroutine and run the OverlapBox in it. It worked like charm.

#

Thanks for helping.

signal basin
#

If I instantiate an object with a Rigidbody (say inside a FixedUpdate call), will that new rigidbody be used for physics simulation on that same FixedUpdate tick? Or will it wait until the next tick?

timid dove
#

it's either right before or right after, I forget which

#

It's right before - so the new Rigidbody will be simulated in the upcoming physics sim.

signal basin
dreamy pollen
#

Anyone experimented with making their physics-based player an invisible "pawn" and having the rendered representation be updated in the Update loop and then managing your own interpolation?

#

Are there any guides on this or success stories I could look to? I've been fighting unacceptable stuttering/jittering on my player for as long as I've ever used rigidbodies, regardless of interpolation settings, and mostly regardless of fixed timestep settings (maybe something like 1000hz would look great but there's no way the performance hit would be worth it)

bronze lake
#

Idk if this this the right place to put this but I have a third person camera and a controllable character, the person walks fine, but wasnt affect by gravity, so I gave the camera and the player object a rigbody so both would go down the hills and not just float. But they both fell trough the terrain, so I gave them colliders so they wouldn't fall through the ground, but the colliders just fall over and roll down the hill dragging the player and the camera, i want the player and camera to walk down the hill not roll down .

timid dove
#

You can't just bolt it onto another movement scheme

#

Just add gravity to your existing control scheme yourself

forest salmon
#

Hello there, I have an issue trying using velocity.magnitude to set bool for an Input, But it doesnt seem to work...need help

Here is the Code : https://codeshare.io/VZZ4Qz

shell adder
forest salmon
shell adder
# forest salmon

can u do a debug.log(isCueStopped) after the if else statement

forest salmon
#

Yup in a min

#

Its for a multiplayer 8 ball pool game

shell adder
#

so the bool is set correctly

#

what's the issue

forest salmon
#

the magnitude isnt changing when the ball moves

#

Its still 0

#

I'm trying to access magnitude to stop input while the ball is moving

shell adder
#

that's because u set mag only in the start function

#

if u want mag to change u gotta set what it is every update (or preferably every fixedupdate since ur interacting with physics)

#

so in the start u should get the rigidbody by doing
Rigidbody rb = GetComponent...
then in the fixed update do
mag = (int)rb.velocity.magnitude

forest salmon
#

Thank you i was able to fix the magnitude issue but I'm trying to stop the input while the ball is in motion...but i couldnt....

shell adder
#

because (int) will just drop the decimals while roundtoint will round it

shell adder
forest salmon
#

As a 8 ball pool game, i need to access the player movement only when the ball is stationary

shell adder
#

ah ok

shell adder
# forest salmon

so ur doing addforce in mouseup but u don't check if cue is stopped

#

also an optimisation thing, u should do getcomponent only once in Start() because it'll slow things down to call it every time in OnMouseUp

#

oh wait sorry i didn't see the coroutine

forest salmon
#

:'>

shell adder
#

because currently i think all it does is wait for 5 seconds

frigid pier
shell adder
#

if u want it to wait until isCueStopped = true then u can do a while loop

forest salmon
#

also i needed it for a 5 sec cooldown between each moves

shell adder
#

ah ok

forest salmon
#

Thanks Btw :>

prisma terrace
#

Hey fellas, what do you do when you have a rigidbody with multiple children that each have a trigger collider, and you want to know which one got triggered?

#

(since I have to put the script with OnTriggerEntered on the rigidbody object)

bronze lake
stuck bay
#

Hellow one question, do one sided effector colliders work as one sided triggers?

#

im making a basketball so i want the ball to only score if it goes in tru the top of the rim oc

#

i was using like 3 checks on a past version of the project but im wondering what would be the best way to do it

shell adder
stuck bay
#

there is no edge collider 3d i just use a "flat" sphere but ill try checking where is going before scoring

shell adder
#

oh ok

stuck bay
#

oh the effectors are only 2d XD

mighty sluice
#

contact mods are neat

thin oar
#

6

mighty sluice
rugged lotus
#

Why is the second one broken? It doesnt detect correctly and says theres nothing above when there is and vice versa ```cs
if (!Physics.CapsuleCast(transform.position, transform.position, controller.radius, transform.up, 1.8f, crouchLayerMask))

if (!Physics.CheckCapsule(transform.position + transform.up * controller.radius, transform.up * (1.8f - controller.radius), controller.radius, crouchLayerMask))```

static plover
rugged lotus
#

i tried to make them the same

static plover
rugged lotus
#

then it returns as always hitting something; i think it hits the ground then

#

my player pivot starts from the bottom

unknown.png
static plover
#

does the first one work?

rugged lotus
#

yep

#

perfectly

#

theres also a weird bug that makes the second one look like its offset; theres a flat door-sized patform that i can crouch under- and it doesnt detect half of it where it is, but detects further down the path where theres no platform

#

this one thinks im still under it

#

the first half of it says theres nothing there thonk

rugged lotus
#

@static plover any way to accurately visualise the colliders/casts in unity?

static plover
#

don't think there's a internal unity function that draws capsules but there is code out there if you google

#

otherwise you can just draw the spheres

rugged lotus
#

yeahh i dont think its gonna be accurate if i do it 😄

static plover
#

if its the same parameters as your capsule casts it should be the same

rugged lotus
#

well just from the looks of it it should be working just fine

#

but it isnt eyesShake

#

there always seem to be trouble with these non-alloc casts

proud nova
#

Are you clearing your reused lists?

#

The most common issues seem to be not sorting the results and not clearing the results from previous casts.

empty rock
#

Hello
I use bolt, I finally managed to make a projectile system with
my only problem now is that the projectile instances spawn at the correct coordinates, but are not childs of my gun so they continue to float in space when I move my player during the game

wide nebula
#

You should only be spawning a bullet when you need it.

empty rock
#

that's what i did

#

but when i left click, it spawns the bullet, but i have to left click again to make it moving

#

and Since the bullet instance isn't parented to the gun, i get that problem.;

shell adder
wide nebula
#

Just to be clear, you want the player to click twice to fire a bullet?

empty rock
empty rock
wide nebula
#

So the issue has nothing to do with it not being a child of the gun then, it's the fact it's not firing when you click?

empty rock
#

i think i have 2 issues now

#

this is the instances script

unknown.png
#

and the bullet script

unknown.png
wide nebula
empty rock
#

Oh
ok

#

ty

wide nebula
#

But from the sounds of it, if you solve your 'click once to fire' issue, then the parenting issue is irrelevant.

empty rock
#

Yea

pure spire
#

Hello!
I know I'll be off-topic, but I really need some help. I'm trying to make my own 3D "game engine", and I got stuck in a really tough thing to do, collisions. I'm working in C++ and I kinda have a script, but it won't work.
https://pastebin.com/6mGvUNZG

timid dove
#

if it's not about Unity, it's off topic.

pure spire
mighty sluice
#

contact modifications are like the shaders of physics

#

also; mace

twilit axle
sweet snow
twilit axle
#

@sweet snow Thank you

lost lagoon
#

Any suggestions for how I should go about implementing collision for my game?
I want to make it so that entities are stopped when they collide with other objects/entities without applying any forces to the object/entity it collides with.
I'm not using physics in any other way in my game so, for my current implementation, I'm detecting collision with OnTriggerEnter and applying the last valid position. Currently I'm experiencing a bug where I'm able to walk through the object if I spam the movement button enough times

shadow seal
#

very odd

#

I want to know why you want collisions to exert no force

#

because I can't think of why that would warrant a custom physics implementation

#

can't you just set some object's mass to near 0?

gilded sparrow
#

Anyone know the full list of scenarios where OnTriggerExit might not get called?

Like the collider gets warped is 1? Or not actually? Or destroyed?

shell adder
#

in https://docs.unity3d.com/ScriptReference/Collider.OnTriggerExit.html
it says

Notes: Trigger events are only sent if one of the Colliders also has a Rigidbody attached. Trigger events will be sent to disabled MonoBehaviours, to allow enabling Behaviours in response to collisions. OnTriggerExit occurs on the FixedUpdate after the Colliders have stopped touching. The Colliders involved are not guaranteed to be at the point of initial separation.

gilded sparrow
#

Yeah but it doesn't say some fail cases

#

I keep a list<Collider> inside often and as far as i remember i always need a CleanupList() function to be called once in a while
Just annoying to always have to figure this out all the time

stuck bay
# empty rock i think i have 2 issues now

When the mouse button is clicked the Particle system will be played and the impact idk the code and if you're using RayCast it will be Instantiate(theimpactname, theRayCastHitname.point, Quaternion.LookRotation(theRayCastHitname.normal));

empty rock
#

Thank you

stuck bay
#

if you need any help message me privatly ok?

empty rock
#

Ok!

next stirrup
#

so question...when I go into the Physics 2D settings and turn off some collisions are the triggers also disabled? and if yes what is the best solution?

timid dove
#

yes it disables triggers on those layer interactions as well

next stirrup
timid dove
next stirrup
next stirrup
stuck bay
#

I am trying to debug a 'procedurally generated' mesh collider. I get the error [Physics.PhysX] Gu::ConvexMesh::checkHullPolygons: Hull seems to have opened volume or do (some) faces have reversed winding?
I have no idea what this could mean. It seems like each triangle is well connected. I have also created a script that inverts through all possible combinations of triangle windings and I get the error on each iteration.
This happens when I'm trying to make the mesh convex by setting MeshCollider.convex to true (unity)
any ideas?

stuck bay
stuck bay
gleaming cobalt
#

hey, is it possible and is it worth it(or does unity already do it) to adaptively switch between discrete and continious physics updates

indigo ivy
#

I imagine in some very specific scenarios it might be proven worth it but overal it's best to just stick with one simulation method for your unity physics objects and let physX handle it

#

you may run into some physics objects that need continunous or continuous dynamic when moving really fast and relying on the physics but in those scenarios the more ideal solution is to either slow your stuff down or if you really wanna go hard on it decrease the physics timestep. ... OR i mean if you are dealing with really fast like sonic 2d level of collisions then write your own with some extrapolation

stuck bay
#

@gleaming cobalt Unity does that automatically. Actually you can't even guarantee a full continuous collision detection with unity. If you delve into things deeper, you will notice that sometimes objects intersect in specific frames, even with continuous collision detection turned on. This is because PhysX has this feature of adaptively switching between the two, and unity does not provide a way to turn it off.

gleaming cobalt
#

thank you guys

tawdry dawn
#

Hello, i have a problem with mesh collider and trigger. For some reason, the trigger placed on a gameobject doesn't detect when the mesh collider leaves the trigger (or more specifically, when trigger moves far enough that mesh collider is not inside the trigger). Mesh collider is set to be convex, and the mesh itself is generated by code. Any idea what might be wrong here?

timid dove
tawdry dawn
#

the trigger gameobject has an OnTriggerExit in it's script

timid dove
tawdry dawn
#

yes, there is a rigidbody on the trigger gameobject (the moving one), and both do have 3D colliders (trigger - box, static gameobject - mesh)

timid dove
#

hmm that should work 🤔

tawdry dawn
#

for comparison, the OnTriggerEnter and OnTriggerStay work flawlessly

timid dove
#

show the code? Maybe there's a typo?

tawdry dawn
#

just a thought - is it possible that it's actually caused by the mesh in mesh collider? Since for example, meshes exported from blender work correctly, for trigger enter/stay/exit, but the mesh generated by my code causes problems with exit detection

#

here's the code for trigger exit

void OnTriggerExit(Collider coll)
    {
        if(tags.Contains(coll.gameObject.tag))
        {
            canPlaceBuilding=true;
        }
    }```
#

it seems correct to me and it actually works, just not in this one specific case

shell adder
#

so i'd try with another collider instead of the mesh one to see if that works

tawdry dawn
#

it works if i add a box collider for example, but using any other collider won't help, because my goal is to make a custom collider basing on a mesh generated in real time

shell adder
#

so is the mesh collider set to isTrigger

tawdry dawn
#

no, the mesh is just a collider for the obstacle, the trigger collider is on the building and the script is attached to it

shell adder
#

oh

shell adder
tawdry dawn
# 
public class QuadCollider : MonoBehaviour
{
    public Transform[] vertices;
    Vector3[] _vertices;
    int[] _triangles;

    void Update()
    {
        if (vertices.Length > 0)
        {
            Mesh mesh = GetComponent<MeshFilter>().mesh;

            mesh.Clear();
            _vertices = new Vector3[]
            {
                vertices[0].position,
                vertices[1].position,
                vertices[2].position,
                vertices[3].position
            };
            _triangles = new int[]
            {
                0,2,1,
                3,2,1,
                3,1,0,
                3,0,2
            };

            mesh.name=this.name;
            mesh.vertices = _vertices;
            mesh.triangles = _triangles;
            GetComponent<MeshCollider>().sharedMesh = mesh;
        }
    }
}```
#

technically it should be ok. Normals and UV are not being set, since those things are not needed for collision detection afaik

shell adder
tawdry dawn
#

both in runtime and in editor, the outline looks alright

shell adder
tawdry dawn
#

everything in cooking option is enabled. No matter if enabled or disabled, still doesn't work

shell adder
#

so in the doc it says

Faces in collision meshes are one-sided. This means GameObjects can pass through them from one direction, but collide with them from the other.

#

does the collision not work from both directions?

tawdry dawn
#

it seems like the collision works on the entire area of the mesh collider. That is, it keeps detecting OnTriggerEnter and OnTriggerStay but doesn't detect the OnTriggerExit

#

umm... it turns out that... turning off the mesh generating script fixes the issue

#

oooh i know why. Because the mesh generating script keeps generating new mesh

shell adder
#

oh and ur doing that in update

#

when u should in start

tawdry dawn
#

ye. I mean, i was doing that in update so i can see what happens in the editor, but then in the game it messes up everything

shell adder
#

i see

#

so does moving it to Start fix it

tawdry dawn
#

ye, seems like it does fix that

shell adder
#

nice

tawdry dawn
#

thanks for trying to help!

dark maple
#

can i get help u see imported a 3d cube but when i place my player on top of it he falls through the cube
any ideas??
(Sorry im a bit of a noob)

shell adder
dark maple
#

no it doesnt

unknown.png
dark maple
#

im going to do it rn

#

which colider do you recomend? there is alot

shell adder
#

if it's a cube then box collider works

#

click the edit collider button and see if the collider's shape matches with the model

dark maple
#

yes its a cube and i also ned to do a ramp too lol

dark maple
shell adder
dark maple
#

do i turn on is trigger?

unknown.png
dark maple
shell adder
dark maple
#

oh wow IT works!

#

thats awesome!

shell adder
#

nice

dark maple
#

how would i do a ramp?

shell adder
#

u can do a boxcollider and rotate it to be the angle of the ramp

dark maple
#

OHHH tahts smart thank you once again

obtuse ocean
#

Is it better to use a KinematicBody2D or a RigidBody2D?

dark maple
shell adder
dark maple
#

Yesh

shell adder
# dark maple Yesh

don't use too many meshcolliders as they can be resource intensive and can slow down ur game

dark maple
#

Ohhhh ok I see

shell adder
#

instead u can use boxes, spheres, and capsules and then attach a composite collider

dark maple
shell adder
#

that's most likely a separate issue

dark maple
#

OHHHH ok

eternal fable
#

Hi! I need to create cloth animation for a canopy that would cover a tent in the virtual world. The models are all made in Maya or 3D MAX.

Cloth/ canopy has to be animated at different levels of tension. The user can select tension of the cloth, so that it changes the way that the cloth hangs (to get a different look).

It would also be nice to add animation to the cloth / canopy, so that it moves slightly in the breeze. Obviously, this animation would be different at different levels of tension.

Is this something that can be done in Unity? Or do I need to create everything in the 3d modeling software and then import into Unity?

I have spoken with a couple of artists, and people are giving me different answers.

4.jpg
static plover
eternal fable
gritty dagger
#

I couldn't find any source about Obi Rope. if you have can you share

proud nova
#

@gritty dagger What do you mean?

gritty dagger
#

I mean that I couldn't find any video or documentation on how to use obi Rope components.

proud nova
#

It should come with documentation

#

Additional info can most likely be found on their site and forum

gritty dagger
#

it has a huge library and its docs not clear for me.

static plover
gritty dagger
#

yes but it shows neither all components nor combinations

#

they also have a youtube channel but it's more like a showcase

#

anyway thanks for your help and let me know if you find more

static plover
#

or just experiment with the components

light hound
#

I have a character controller for a horse that walks on two legs (like Bojack Horseman), but when he walks up to other horses, their giant noses intersect each other. i tried adding colliders to bones, mesh, parent with the controller, but none of that worked. ANy tips?

exotic coyote
#

anyone here who has done collison physics for cars in unity?

copper olive
#

The nav mesh agent

#

Of the enemy

#

Keeps sliding under my character and blasts my character off the map

#

What should I do?

wide nebula
#

Not crosspost, is what.

#

But seeing as this is where this question belongs, it depends on your implementation of your agent.

#

Do you have a rigidbody on it, for example?

copper olive
#

Yes

#

And a capsule collider

wide nebula
#

Remove the rigidbody.

copper olive
#

I need the rigidbody

wide nebula
copper olive
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I read that

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Doesn't match with my situation

wide nebula
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Show your agent's inspector.

thorny sonnet
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Hello - I've been completely stuck on something that should be incredibly simple for the past several days: I'm trying to create a child object that is both a trail renderer and some sort of trigger collider (all in 2D). I've tried using a PolygonCollider2D and updating the vertices of the polygon to match the trail each frame, but it doesn't trigger when a player walks through the trail - moreover a ghost object spawns at the origin which for some reason acts as both a trigger and a solid collider. For context, I am trying to attach this child object to a bullet in the game. The trail (visually) works just fine, but for the life of me I cannot get it to detect when a player has intersected it

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Any help or resources I could read through would be massively appreciated - thanks in advance!

frosty ore
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AddForce of -transform.up * 1f is about equivalent to a rigidbody with a mass of 1 ??

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It looks pretty close to me but i wanna be sure before i build onto it

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this controller is practically a kinematic rigidbody..im trying to simulate weight of the player.. this is addforce of 1 downward

summer fog