⚛️┃physics

[chilly maple]

ok

i got this problem

u see, i am setting the velocity of a 2d rigidbody to a value such as 2 or 3.

but for some reason, it is not moving

wait

lemme try something

[chilly maple]

ok

i think the problem lied with the tilemap2d collider

i changed it to a temporary Polygon collideer

and it is working

[spiral escarp]

is there any real downside of changing springjoint's spring value to 0 instead of destroying it every time?

[timid dove]

it continues to use resources I guess

[wispy patrol]

Hi there, I have a car that stutters and I tried adding SmoothDamp and it still stutters but the game's environment looks smoother

[last veldt]

I'm not really knowledgeable on unity yet but a guess i'd have is a weird collider interaction

[wispy patrol]

That was it. I need to bring down spring suspension and spring dampness 🙂

[last veldt]

lets gooooo

[wispy patrol]

Yeaaaaaa

Thank you Pickle

[last veldt]

yeah np

Does anyone know how to link up physics so they aren't reliant on the framerate my projectiles keep passing through my enemies because they are too fast?

[wispy patrol]

I have this problem when my car goes too fast and hits the ground. Seems to be a mass issue.

[last veldt]

I've changed the mass it didnt make a difference what I'm betting on is there is a line of code that I just don't know that syncs physics to the world at this point I might just add a raycast instead though

[tall monolith]

how can i detect when 2 object collide with each other with a strong force

[nocturne lagoon]

Hello again! im not sure where exactly to put it but: (posted it also in the general code just in case it belongs there)
Im trying to find this green vector and Ive got three points A, B, C. How can i find that vector in unity?

[viral ginkgo]

var projection = Vector3.Project(C - A, B - A);
var green = C - (projection + A);

@nocturne lagoon

Plug in 0,0,0 for A to see it better if you want.
The above one is orientation/position independent.

if A is origin:

var projection = Vector3.Project(C, B);
var green = C - projection;

[nocturne lagoon]

thank you!

[vital goblet]

Hi there! I'm fairly new to unity overall, I was trying to make car suspensions through rigidbody and raycasting

Rigidbody.AddForceAtPosition(ray.direction * -SuspensionForce, hit.point);

this is what I'm using to add the force to the rigidbody, but even by adding Drag this keeps happening, any idea on how to fix it?

[timid dove]

Real spring forces don't apply constant force, there's a proportional force to how far they are stretched away from the resting position

[vital goblet]

then I should just be able to apply the inverted force that is being casted on the individual raycast to get a stable suspension, right?

sorry if my english isn't great, I'm not that good at explaining my ideas

[viral ginkgo]

@vital goblet your force should be proportional to distance offset the suspension is stretching

if its stretching 10cm, lets say the force is 10 units

if it stretches 20 cm, the force should be 20 units

and you should also do dampening on the axis where movement happens

To prevent oscillation

if the strech is happening at 1cm per frame, you apply 1 unit of force in the opposing direction
if the strech is happening at 2cm per frame, you apply 2 unit of force in the opposing direction

thats basic pd control

[vital goblet]

yup that was exactly what I was thinking of doing, not too familiar with C# or raycasts in general, I'll see what I can do

thank you

[viral ginkgo]

np

[quartz wyvern]

is it possible to move a rigidbody but keep it bound to a navmesh some how

was a bit weird using it with navmesh agent so that wasn't an option

[wide nebula]

I think Tunic uses that technique. You can sample a mavmesh without actually moving on it. So you would have to check if a future position of the RB would be on the mavmesh or not.

[quartz wyvern]

right so i dont need a navmeshagent i just need to query the navmesh surface

i'll give it a try

[quartz wyvern]

oh nice that worked better than i expected thanks!

[last veldt]

if anyone wants to know what I did it's even simpler than I thought under collision detections i just had to set it to continuous

[last veldt]

if you have rigibodies and colliders the force should be applied your question is kinda vague though so you might not be asking the right thing

[tall monolith]

I want to play a sound when the ragdoll hit the ground, but only if it hits with a strong force

[quartz wyvern]

if you set detectCollisions = false whilst inside of a trigger collider, will this trigger a OnTriggerExit

trying to debug right now and can't figure out why its not triggering

[last veldt]

this is me completely bs ing but maybe it'll help. Try set an if statement that tracks the speed of the character under a trigger method (not sure if method is the right word) if it hits a certain speed threshold in the ground collide then you play the audio. Hope this helps

[last veldt]

I'm new so this might not help but to me it seems it's because you set detecting collisions off so it wouldn't detect anything including an OnTriggerExit

[quartz wyvern]

maybe

ill do some tests later

[last veldt]

yeah hope it helps

[split dew]

would this be the right channel for a question regarding particle systems?

If so, I am basically trying to stop particles from clipping through walls. Played with collisions already but there are still these weird lines

[uncut cliff]

hi. so im using navmesh agent and area is baked too. and upon start, agent just moves slightly up. i want it to stay on ground. any ideas?

[winter jetty]

@uncut cliff it could be the parent objects origin being down below the visible 3D objects. unparent all the children components, click <- persp on the top right of scene and click one of the side axis to ensure the origin of the parent object is on the ground maybe.

[uncut cliff]

no i tried moving it really up and it tps down to exact height which is slightly above ground

[uncut cliff]

as shown here

[winter jetty]

hmm not sure but there are a good few threads on it. try this pasted thing

You should change inside the Nav Mesh Agent Compomenet the agent size. You should use it to build a collider around the player. Adjust the radius so that your player fits inside and adjust the height in such a way that it contains your whole player. If the collider is not centered, use the offset to centre it.

[uncut cliff]

i edited the base offset again and again till it is now on the ground

not sure if its the best practice

[quartz wyvern]

im having annoying issues with my RB movement, im moving it with move position and its really jittery some times - other times its buttery smooth... not sure why or how to solve it... this is how i move it:

        void MoveTowards(in Vector3 dir)
        {
            float speed = 2f; //test value
            var pos = _rb.position + dir * Time.fixedDeltaTime * speed;
            if (NavMesh.SamplePosition(pos, out var hit, _navmeshThreshold, NavMesh.AllAreas)) //dont walk outside navmesh area
            {
                var point = hit.position;
                _rb.MovePosition(point);
            }
        }
        void RotateTowards(in Vector3 dir)
        {
            var look = Quaternion.LookRotation(dir, Vector3.up);
            var rot = Quaternion.Slerp(_rb.rotation, look, Time.fixedDeltaTime * _rotSpeed);
            _rb.MoveRotation(rot);
        }

im not using kinematic as i still want collisions - what could the jittery movement be caused by ?

i call these functions in fixed update

you can see it here after i hit the box my movement is jittery

although the gif fps makes it a little tricky to see

my rb is not kinematic

[viral ginkgo]

@quartz wyvern Hmm, try locking y rotation maybe?

[quartz wyvern]

oh that seemed to have fixed it

[viral ginkgo]

Also set the rb.velocity to zero in fixedupdate

[quartz wyvern]

thought i needed that unlocked due to using move rotation

[viral ginkgo]

nope

[quartz wyvern]

so the locked rotations only apply specifically to applied forces not move functions

[viral ginkgo]

Your issue probably accumulating rotational velocity

While you are using the rotation sets

[quartz wyvern]

yeh the jittery stopped if i stopped moving for a second or two

[viral ginkgo]

Maybe it was messing with interpolation

But I was suspecting linear velocity really

[quartz wyvern]

i'll zero them out every frame just to be sure

[green needle]

when some can help, i have a simple player and a simple room, when ever i go to a corner the and try to essentaly push my self out, my charicter starts rotating slightly to a side on the y axis and it dosent stop the slight rotation, how could i fix this

nvm i fixed it

[rare relic]

How would I go about attaching a cloth between two points? I.e. like below, where the one end of the rope is statically attached to the hull, whilst the other would move along with the rotation of the center boom?

[untold tundra]

Hi idk if this problem goes here but i model a character in blender rigged and animated with mixamo and when i upload it in unity collider is too small or in a different place like this.

I checked the origin point rotation and scale in blender they all seem okay any idea why this is happening ?

[timid dove]

#🔀┃art-asset-workflow

[sudden hinge]

Hello, I'm trying to do a stack of coins but they don't stop jittering.
There is no special code attached, and we tried to use rb.interpolate but nothing change, any ideas please ?

[timid dove]

interpolation doesn't do anything to the physics simulation

try playing with things like Sleep Threshold, Default Contact Offset, etc... in the physics settings

[leaden sigil]

Okay so i made this rope.

But as you see it bends a bit.

If you know what i mean by that, The different rope pieces keep overlapping each other, they have an collider tho.

Anyone know how to solve this?

Like this:

[stuck bay]

Now I got the Kart to stop rotating on its OWN axis but now its rotating with the axis of the Sphere collider like a Ferris Wheel

[unique cave]

You could use numerous rigidbodies and joints to make the rope but Id just simulate the rope myself with simple C# script assuming you dont necessarily want the rope to be able to interact with other colliders and physics bodies (so it would just swing freely without taking its envirnonment into account)

[warm pilot]

does an ArticulationBody contain JointDrive s?

it seems likely but it's not explicit in the documentation.

[wraith junco]

So in my raycast wheels I'm trying to implement a good simple working sideways friction. I've tried using the dot product to simply counter the gravity and I've even tried simply countering the true velocity of the wheels (F = MA) but the car still inches slowly downward when sideways on a slope

What am I missing?

Both of the above methods work if there's no suspension on the car, it's like there's some force being applied by the suspension that I'm missing

[wraith junco]

SidewaysDrag = transform.InverseTransformDirection(SidewaysDrag);
SidewaysDrag.y = 0;
SidewaysDrag.z = 0;
SidewaysDrag = transform.TransformDirection(SidewaysDrag);

// Acceleration = velocity / time
// Force = mass * acceleration
_Rigidbody.AddForceAtPosition((-SidewaysDrag / Time.fixedDeltaTime) * (_Rigidbody.mass / 4), _RaycastHit.point);```

This is the sideways friction code running on all of the wheels. The car ever so slightly is gliding down the slope. If I apply this to the ACTUAL car rigidbody's velocity (without the .mass / 4, just * .mass) it works fine and cancels out all sideways velocity

I'm just curious as to why it's not doing what I want

[plucky coyote]

Hey guys is there a job system version of physics.checksphere? i know there is raycastcommand for the raycast but i'd like to know if there is a checksphere version (not spherecast but checksphere)

[somber kestrel]

can I have multiple colliders (triggers on) on a GameObject and depending on what collider has been distracted process a certain method?

I know I could have children with their own Rigidbodies and Colliders but how would I catch their collisions in the parent script then?

my case is

I have a location and many interactive spots where you get different possibilities so I have to know from 1 script what collider the player stepped in

death/ warning message/ teleport back .. colliders

[timid dove]

give the children their own scripts and colliders (they don't need a Rigidbody, just one on the parent will do). Have the child script detect the collision and report it up to a "master" script on the parent by calling a function on the parent script

[somber kestrel]

damn that's bad

I wanted to avoid scripts piling up

[timid dove]

it's one extra script

[somber kestrel]

but you tell me the opposite

[timid dove]

¯_(ツ)_/¯

[somber kestrel]

one? hm yeah maybe

[timid dove]

Most mature projects have hundreds/thousands of scripts.

As long as the game is not trivial

[somber kestrel]

hm unluckily I have never seen a large game made in unity from the editor perspective

anyway still I'd like to

[lofty coyote]

Hi (I'm sorry in advance if I didn't understand your explanation properly, and if I'm telling you stuff you already know::), I think the friction needs to vary per-tyre depending on how much pressure the wheel is exerting on the road? I think the pressure each wheel exerts on the road will depend on the suspension compression? @ me if you reply, I may not notice otherwise:) (you can DM if I don't reply to your reply:)

If you can afford it (semi regular 50% off sales), https://assetstore.unity.com/packages/tools/physics/edy-s-vehicle-physics-403 is a superb "simple" vehicle physics implementation with full source code. If you're making a game (I guess as far as "simcade", like GTA-like driving; for proper simulation the same developer makes "vehicle physics pro" https://assetstore.unity.com/packages/tools/physics/vehicle-physics-pro-community-edition-153556 ; https://vehiclephysics.com/about/features/), I'd strongly recommend it. Even if you're trying to learn about how to do this yourself, Edy's already solved a bunch of awkward problems, working through the EVP source is how I've learned a load of stuff about vehicle physics (tl;dr: it's hard😅 ).

[leaden sigil]

Why is my rope folding like this? I am making use of bones.

https://cdn.discordapp.com/attachments/888153614596595762/1001900559206457344/Collab_-_Zipline_testing_-_Windows_Mac_Linux_-_Unity_2021.3.4f1_Personal___DX11__2022-07-27_19-13-36.mp4

[covert comet]

Hello!! :) I'm wondering how I would set a particular collision up.

Here's a a player object facing a simple enemy. The enemy shoots a projectile at the player every few seconds. The things I need to happen are:
-The projectile should not collide physically with either the enemy or the player, but be affected by the projectile collider and the enemy/player collider overlapping.
-The projectile should be able to have their velocity and trajectory manipulated (rotated, mainly).

I was trying to use Rigidbody components for this but it's soooo clumsy. All I want to do is rotate the projectiles to move towards the player gradually (not simple a LookAt() call.) And I want trigger events to happen when the projectile hits the player.

What should I do here?

[timid dove]

You definitely want/need a Rigidbody here.
You will also want a trigger collider on the projectile, and use OnTriggerEnter to handle the collision in code.

As for the movement, you could make the rigidbody kinematic, which will let you completely control it in code. You can then use rb.MoveRotation to control its rotation, and rb.MovePosition to control its position. You should do these things in FixedUpdate

[covert comet]

That's what I'm doing. I'll update and see if there's a particular problem with this.

[covert comet]

The code for instantiating the enemy's projectile.

The enemy's projectile's fixedupdate.

The enemy should be shooting at me from ITS origin, but instead, all these projectiles are spawning at the origin. Very strange.

[viral ginkgo]

I suspect the parent object named "Zipline rope" might be scaled

If you scale a parent gameobject, and then rotate its children you get these kinds of issues

If that's the case, just make sure the parent scale is 1,1,1

[leaden sigil]

That's not the problem i am trying to showcase, thanks tho.

Its the folding.

[leaden sigil]

The weird folding.

[viral ginkgo]

Ah, yes

@leaden sigil I think you have weight paint on this

I'd just use seperate quads

With no vertex sharing between segments

Does it behave differently in your mesh editing tool?
I think it would look the same there as well

[timid dove]

your FixedUpdate is responsible for this

MovePosition requires an absolute world space position to move to

you're giving it a direction vector

[leaden sigil]

Nope.

[timid dove]

you'll want something like:

void FixedUpdate() {
    rb.MovePosition(rb.position + rb.rotation * Vector3.forward * Time.deltaTime);
}

[covert comet]

Aha

Thank youuu

[viral ginkgo]

@leaden sigil Hmm, I dunno

What's wrong with seperate quads anyway

I think thats gotta be very common in games with 2d ropes

You should just model a simple quad

And instantiate a chain of it with a nice for loop

Have different lengths of rope as well

[leaden sigil]

Or just use many hinge joints.

[viral ginkgo]

@leaden sigil I was suggesting generating joints in the for loop

so you can have variable length ropes

[leaden sigil]

No idea how todo that lol.

[viral ginkgo]

Well then that's probably going to be a nice practice

unless you are in a hurry

[leaden sigil]

Nah lol.

[polar leaf]

I'm making a space dogfighting game (like Elite Dangerous and Star Citizen). As any of these games, ships and projectiles are super fast. This works extremely bad for collision detection. I've already made the projectiles bigger, changed Collision detection modes but it's still janky as hell (hits have a very hard time registering). Any tips for this?

I'm using trigger colliders. In my test I'm testing against a small stationary target

[quasi shuttle]

hello, i have an enemy with 20 colliders in bone objects. It causes huge physics times when there is about 15 enemies on quest 2 build. What would be the best approach to fix performance from colliders? 1 big collider works bad on vr :/

[wraith junco]

Yeah I talked to a few smart guys and apparently the way to solve this (for arcade type cars, nothing fancy) is to have the suspension addforce in the global up direction, instead of relative to the wheel well

That + the frictional sideways damper seems to cancel out the sideways sliding pretty well

One thing I noticed is that the physx wheel colliders seem to suffer from the same sideways sliding on a slope (unless I'm just not setting them up correct).

[twin nebula]

So I've got a config joint and I'm setting the target position to a transform and the drives for X Y and Z are 6000 power 50 damp. I've tried others but it literally does nothing. Also most of the time it'll droop below the target

[empty cipher]

most likely because it will depend on your frame rate. if projectile is able to move 2 frames you might miss it. If it is extremly fast you can do it hit scan instead using raycast. and then just animate your lasers without coliders.it will require some tricky math to do, but htat would solve the problem

[steel mortar]

so for some reason the gameobject just glides up

when adding a character controller

without the controller it doesnt

[timid dove]

You shouldn't have both Rigidbody and CharacterController

Pick one

[wraith junco]

Physx collision detection is an awful way of doing bullet collision detection. Every physics tick, save the position from the last tick and the current tick of the projectile(s) you're working with. Shoot a line between them. If the line hits something, then you can determine that your bullet hit something

[tribal bobcat]

Why my character controller component don't show gizmos for the capsule that's creating ? i'm using 2021.3.2f1 version

[bleak umbra]

select the object, make sure its not folded, make sure you are in scene view, make sure gizmos are turned on, make sure its actually in view and not too small/large

[tribal bobcat]

Nope

Not working

Is it a bug?

[bleak umbra]

no, you are doing something wrong

[tribal bobcat]

U sure?

First image using capsule collider

2nd using character controller

Yet no gizmos

[bleak umbra]

is it disabled in the gizmo menu?

[tribal bobcat]

Oh

It was not

My bad

[tribal bobcat]

I meant it wasn't enabled

Thanks

[ripe sky]

Okay can someone help me with this

it's a video of my problem

it's not a virus or anything, it's just an flv file I recorded in obs

[timid dove]

put it on youtube or streamable or something

or directly embed in a format discord supports like mp4

[mild swan]

hi, i have trouble adding collision so that my character arm does not pass through the walls the way i made it make it hard so if you think you can help me... Please pm me or create a thread so that i can explain further and add image as well as screen-share. i would be grateful if you could help 👍

[ripe sky]

didn't know discorded supported mp4😅

[viral ginkgo]

@ripe sky I am thinking your cars initial position might be outside the area where collisions work

check this out in physics settings

here

your initial coordinates were outside the 250 extents from origin

second coordinates were inside

You should probably think about having the mesh colliders in chunks.
And have a system to shift the world origin
So your coordinates don't ever get extreme

If you want to make a game with big maps

If you just want a quick fix, just increase the world extents

I'd also increase the world subdivisions
You can set extents 1000 and subdivisions 10 for example

[ripe sky]

Thanks for the tip! However, this didn't really change anything in my case. I did even try to move the tunnel to a place where I already had a working (but smaller) one. My car fell down on the exact same spot, when I drove inside the tunnel

[uncut sable]

I have a little flag attached to the top of my tank, the flag has joints that go up it so that it will bend around as the player moves. However, my movements dont seem to be affecting the physics joints. How do I achieve this?

[wraith junco]

I could be wrong, but a joint might need two rigidbodies to work

so you might need to add a collider and rigidbody to your flag

then you probably need to reference both rigidbodies in the joint

[uncut sable]

ill give it a try!

it bends perfectly fine when the head of the tank rotates on the X and Z axis but when it spins on the Y axis which is the only axis that it's supposed to in my game, there is no effect lol

[wraith junco]

I mean you could manually apply force to it, based on the angular velocity of your tank

you might be doing something wrong with the joint though, I don't really use these things

How are you rotating the tank?

To rotate any physics body without breaking it from the physics engine, you should be using addtorque

I think its called that

you definitely shouldn't be applying manual rotations if you want it to maintain it's physics capabilities

https://docs.unity3d.com/ScriptReference/Rigidbody.AddTorque.html

[uncut sable]

rip haha i definitely am applying manual rotations

[viral ginkgo]

It would drop through the surface with default settings i mean

At x = 320 like in your video

[charred pelican]

I'm trying to make a system where a player picks up an object and can hold it.
Currently, it

1. Sends a raycast,
2. turns off gravity and activates kinematic on the object hit by the raycast,
3. Parents and moves hit object to "holding" point
   This system works, but because the object is kinematic it phases through solid objects.
   When it hits other rigidbodies, mass does not seem to take effect either, meaning if I make the picked up object (with a mass of 1) contact a rigid body (with a mass of 1000), it will act like there is no mass at all and hit it away.
   I've tried making it so that the object is not kinematic when it is being picked up, which results in it bouncing off surfaces when they contact anything. Fixes the phasing through solids issue though. If anyone can help that would be great.

Here is footage of that. You can see the pickup working perfectly, but it phases through solid objects. When a light object is picked up (mass of 1) and is hit against an object of mass 1000, mass does not seem to take any effect.

Here's when I set it to not kinematic.

[mild swan]

hi, i have trouble adding collision so that my character arm does not pass through the walls the way i made it make it hard so if you think you can help me... Please pm me or create a thread so that i can explain further and add image as well as screen-share. i would be grateful if you could help 👍
: useful info :
-the character can only turn and can't move.
-when i put rigidbody and collider the arm/racket just disassemble when touching the walls as shown in the image down here.

[haughty smelt]

ok, i just added tires and car physics layer
i dont want them to collide
i want everything else to collide with them
the road (on default layer) isnt colliding with the wheels (they are on on tires layer)

[stiff topaz]

I guess this is technically in physics? I have a 2d Tilemap collider but they have rounded corners

How do I not have this

I want the sharp edges, the rounded edges are nowhere else

not in sprite editor or anything

[timid dove]

you can make a custom physics shape for the sprite in the sprite editor

[stiff topaz]

but they aren't rounded in the sprite editor they're already square

[timid dove]

show it

[stiff topaz]

I did automatic grid by cell size, then did custom shape, hit generate, and removed the rounding, and it's still tha tway

...and did not recreate the tilemap collider.

now it's working thank you

[stuck bay]

hello I am using unity cloth physics to animate a cape. I put colliders on the character dynamically on runtime through a physics prefab. they are set to the ragdoll layer which only interacts with itself. when I collide with other objects my character starts to spin wildly. I can't find an answer at this time.

[winged herald]

So I've found that OnTriggerExit2D doesn't seem to be guaranteed to be called. No, my layers are not set up incorrectly, and I have even enabled the "Send Callbacks on Disable" option in the Physics2D settings.
But when Trigger Colliders are disabled, sometimes, OnTriggerExit2D just does not get called.

Is this a bug or intention? I've found a not so perfomant workaround, but ideally, I'd like to just use the OnTriggerExit2D.

[sullen panther]

Is there a way to stop objects of high mass passing through objects of lower mass.

For example if you have a cube of low mass (1) and then "squash" it between 2 cubes of larger mass (10), the 2 high mass cubes just pass intersect instead of colliding. (if the mass of the 2 cubes was 1 (same as low mass cube) then it collides as expected).

Note, I am moving the objects by settings their RB.velocity component, not by moving their transforms

[tardy compass]

Is there a way to nullify a rb2d's contacts.relative velocity?
i tried to make a character controller by setting the rb.velocity.x, and once it hits the wall, it is told to have 0 velocity both from my script, and in the main rigidbody component, but when you jump, it launches the direction of the wall.
i found that what's happening when i jump is that this relative velocity goes from a wall contact to the normal rigidbody velocity, is there a way to stop this?
Picture: Rigidbody velocity 0, wantedvelocity, which is what im setting the rb.x to, and the weird "Relative velocity" with x=10

[shell gulch]

Im new to this area in game design so I got a question. i have a character that im working on and his robes im thinking of adding cloth physics, and im asking to the people that have experience whats the procedure for it and would it be better if i rig the loose robes and animate them seperately (away from unity ) or have unity to do the simulation and hope it turns out good?

https://gyazo.com/a54c360f642baa9571f87f2bd9c7531c

[timid dove]

I know this is about cloth physics but you probably will have a much better time with this question in #🔀┃art-asset-workflow

[shell gulch]

aight thank you

[fluid lagoon]

hi, is it possible to make a projectile collide with an object without losing momentum ?

i want the projectile to keep going; like a bullet that goes throw a carton box, it should not effect its momentum yet I want the carton to have some sort of impact debri

[polar leaf]

If I increase the time scale, will the physics be the same? (use case: I want to create some training scenarios for my AI and want to increase scale so the training is faster)

[viral ginkgo]

I think what you might want here is just making the projectile raycast based

If you insist on having a collider on the projectile, you could keep track of the velocity from last fixedupdate and restore it in OnCollisionEnter

[carmine basin]

No. As BARGOS says, you would need to raycast in order to do this. Alternatively, put a collider marked as a trigger on the box if it does not need to collide with anything else or does not have a rigidbody

I'm trying to align a rigidbody's up with the normal of the ground below it using torques, as well as turning it around the y-axis to face the camera. Does anyone have any idea how I'd do this?

[timid dove]

physics will not change as long as your physics code was written properly 😛

Also if you want to do AI training, you should just use Physics.Simulate, rather than waiting for real time to elapse

[fluid lagoon]

@carmine basin @viral ginkgo thank you!

[viral ginkgo]

yeah but it will be hard to get a nice collision normal from this
and the projectile might skip thin objects if its made with trigger colliders
@fluid lagoon

[fluid lagoon]

I'll actually use raycast for projecils like this , like u said, it aint the best for what I'm looking for.

[viral ginkgo]

void ControlRotation(Rigidbody controlled, Transform target, float p = 1, float d = 1)
    {
        var deltaRot = target.transform.rotation * Quaternion.Inverse(controlled.rotation);
        deltaRot.ToAngleAxis(out float angle, out Vector3 axis);
        var moveToTargetTorque = (angle * axis) * p;
        var dampeningTorque = controlled.angularVelocity * -d;
        controlled.AddTorque(moveToTargetTorque + dampeningTorque, ForceMode.VelocityChange);
    }

from my super secret stash

[carmine basin]

lmao, i'm currently using a series of addForceAtPosition things

it works well, kinda, but I need to tweak to get rid of the wobble

[viral ginkgo]

thats poor mans addtorque

i was once like that

[carmine basin]

It works better for what I want than AddTorque does

[viral ginkgo]

then i obtained this piece of code

the transform that goes in the parameter here

its for getting a target rotation

this is pretty much a rotation set but torque makes it happen in the background

I should've put a Quaternion target in paramater instead of Transform target

Well you can do that

Would make more sense that way

[carmine basin]

I have managed to get it working quite well using my method

and using force at position cuts out the extra faff

easier to read and easier on my autism brain

praetor judging me heavily rn

[timid dove]

yes

[viral ginkgo]

I have spoken

[timid dove]

Add force at position is going to leave you with a net linear velocity

unless you perfectly cancel that out elsewhere

you also have to do a bunch of torque math to figure out how much torque you'll actually add

easier to just add the torque directly

[carmine basin]

I have cut all the extra math out. I'm making a hovering vehicle.

the extent of my math is literally just

        foreach (var item in hoverRayOrigins)
        {
            RaycastHit hitinfo;
            Physics.Raycast(item.position, -item.up, out hitinfo, raycastDistance, layerMask);
            rigid.AddForceAtPosition(hoverNormal * ( 1 - (hitinfo.distance / desiredHeight)) * hoverForce, item.
        }

Its like buoyancy but on land

i promise i know what im doing

[jovial wraith]

Its unclear to me whether you're satisfied with the answer that you got, so I'm going to weigh in. Sorry if it is redundant.

Trying to use AddForce/AddTorque to arrive at a specific target position is simulating the real-world engineering problem that the field of Controls deals with. There is no simple equation of "just add this force/torque and it will work perfectly." You're going to have to set up some kind of control system. BARGOS's code with the dampeningTorque is an example of what this would look like, but how well it works depends on the values of p and d. You have to tune the system to find the correct values of p and d to get the result you want. Higher p values will get it to arrive at the target faster, but also cause it to potentially overshoot and wobble. Higher d values will make it take longer to arrive at the target, but makes wobbles fade faster and potentially prevents them completely.

It's a simplified versions of a PID controller: https://en.wikipedia.org/wiki/PID_controller. Technically it is a PD controller, which is a PID controller with I = 0.

In your math, (1 - (distance / desiredHeight)) * hoverForce is equivalent to the p term (which stands for proportional, as it it is proportional to the distance from your target value). To avoid a wobble you need an additional term that dampens the motion -- a d term (which stands for derivative). It should work in the opposite direction of the p term, and it should be proportional to either the angular velocity of the rigidbody (simpler but less accurate) or the linear velocity of the point you're adding your force at minus the linear velocity of the center of mass (a bit more complex).

The manual tuning section of the PID controller article may be particularly helpful for getting a handle on the concept: https://en.wikipedia.org/wiki/PID_controller#Manual_tuning

[carmine basin]

I did attempt to use a PID controller. However, I seemed to struggle quite a bit with that. I think I was satisfied with the help that was given, even though it wasn't put into practice. I do appreciate your help though, too.

[stone crag]

im new to everything unity and are trying to put a box collider and rigid body on an asset but unity does not allow me to use both at the same time how can i fix this? using 2020.3

[timid dove]

what happens when you try?

THere's nothing wrong with putting a box collider and Rigidbody at the same time, unless you're trying to mix 2D and 3D

[timid dove]

Yeha you';re trying to mix 2d and 3d

RIgidbody can go with BoxCollider
Rigidbody2D can go with BoxCollider2D

but you can't mix and match

[polar leaf]

Hi I'm making a spaceship 3d game (very high speeds) and I am running into all sorts of problems with colliders on projectiles, namely, projectiles hitting other projectiles, projectiles hitting the shooter and projectiles not detecting collisions. What is the best practice here? Seems with normal colliders I can't avoid them hitting the shooter, trigger colliders seem to have worst collision detection and I have read somewhere that you should avoid using colliders at all and have scripts doing raycasts to detect collisions.

[tropic forge]

hello, i made player controller using rigidbody, blocking x and z rotation, if i go to a corner, i can noclip....

[polar leaf]

I just had a similar experience and in my case the problem was the tuning. Tuning them is not easy but my advice is to spend some time around with it. Start tuning each parameter individually and play around not just with amounts but also signs. Now mine is working well

[stuck bay]

How could I make a stick that acts like a ragdoll

[timid dove]

look up a ragdoll tutorial

it's the same thing

[stuck bay]

did , sadly didnt find anything for my peanut brain

[stuck bay]

Just to better ilustrate

( idk if its better )

[inner thistle]

Compare the Y coordinate of a segment to the next one. If it's different, move towards it.

[wise eagle]

is the movement fixed?

[stuck bay]

wdym fixed?

[wise eagle]

fixed isn't a good adjective, I would like to say if is like a animation

normally, to do a animation is a better way.

[stuck bay]

sure but if I move the base randomly , can't really animate that

[wise eagle]

ah ok, I understand

in this case, you need a script that control all plataforms

[stuck bay]

they arent platforms , i want a lighsaber that acts that way

and I thought its better if its segments

[wise eagle]

is it a lightsaber like a nunchucks?

https://www.google.com/search?q=nunchaku

[timid dove]

You could also do this:
give each of the "tail" objects a PositionConstraint component: https://docs.unity3d.com/Manual/class-PositionConstraint.html

Have each constraint follow the object ahead of it in the chain (after baking in the offset with the Activate button), and set the weight of the constraint to like .8

[stuck bay]

I would like it to look like the chains of a nunchaku

[stuck bay]

I will look into it thx

[wise eagle]

Maybe, you can use joints too.

[stuck bay]

looked at them for a good while , never got how they worked

[fluid lagoon]

hey,

what to do when a projectile with sphere collider goes through an object without triggering OnCollisionEnter(Collision collision) ?

[stuck bay]

btw with this would the rotation work like this

[stuck bay]

make it slower, predict impact or use is trigger

3 options

if u dont have bouncy bullets I suggest the 3 option

( use is trigger )

if u need the thing u are shooting to be pushed ,, naturally " by the bullet , use the 2 option

[timid dove]

it would not but if you wanted it to you can do that with RotationConstraints, or combine the two into one with ParentConstraints

[stuck bay]

gotcha , love ya and thx

When I move the "parent cube" , the "move cube" moves half the distance travelled by the "parent cube" and it doesnt move back into place

[fluid lagoon]

i'm not familiar with "predict impact" option , but option 3 is not possible because I need it to collide with other things and I'm not surfe of making the bullet slower option either.. how slow are we talking ?

[stuck bay]

dk

depends on the bullet

[stuck bay]

and with what do u need the bullet to collide?

[fluid lagoon]

props , top table objects like books, bottles , plates, forks .. etc

[stuck bay]

and u want them to just be pushed by the bullet?

[fluid lagoon]

I'll try to slow it down and make collider a bit bigger than the bullet just to see if that would fix the problem

[fluid lagoon]

yes

[stuck bay]

it wont

slow down maybe

but whats happening is the collision is skipped because the bullet move so fast trough frames , it just passes trough the object

I think

[fluid lagoon]

the bullet velocity is just 50 😄

[stuck bay]

weird

[fluid lagoon]

let me try to slow it down ... maybe something else is causing it

[stuck bay]

maybe the layers arent colliding?

[fluid lagoon]

yeah :D, i've just checked,i had 2 layers with almost the same name, i unchecked the wrong one apparently.
I'll try it now

[stuck bay]

lmao

[fluid lagoon]

yup it worked right after 😄 , thanks a lot ^^

[stuck bay]

np

[stuck bay]

I dont understand them

The part that I dont understand is weight

and sources

[timid dove]

I may have been overzealous with the constraint compontns, they might not be able to solve your issue 😛

[stuck bay]

bruh, my love is fading away

[timid dove]

True love is unconditional

[stuck bay]

sadly this one has a "working solution" condition

😉

[stuck bay]

well thx to this I found the lookat/aim constrain, that will help with the rotation part of my problem

so my love condition has been semi-filled

[normal cargo]

i tried to make sloped terrain, with a squeezed sphere and mesh collider, but somehow it seems to suck in the enemies that accidentally touch the small hill. why is this happening? it would make sense that the upward hill would push away objects, and not suck them in?

[cedar trench]

Not really a problem but Does anyone know how to make a titanfall-like movement system in unity

[timid dove]

that's a really complicated system

with lots of parts

break it down and focus on one at a time

[tropic burrow]

anybody here code their own physics? (like kinda) I still use the unity colliders but I made my own acceleration based system. I'm still working on some stuff like particles moving through walls. I was considering using a raycast to stop them before it happens but I dont know if thats good for the algorithm cause its like 20 particles a scene. Anywho would love ideas/comments https://twitter.com/chimp_northern/status/1554620958324965376

NorthernChimp (@chimp_northern)

couple of levels randomized #madewithunity #unity3d #gaming #indie #indiedev #mobile #mobiledev #physics #programming #pixelart

▶ Play video

Twitter · Aug 3, 2022, 12:11 AM

[wise bobcat]

i made a soft body a while back like in this video https://www.youtube.com/watch?v=F82BlnW5z6g and i finished it adn it was perfect but all of a sudden when testing stuff it started making it so when colliding with objects the spings got a new distance instead of springing back like springs

anyone know why springs would get a new distance?

(spring joints)

[wind meadow]

what is a way in unity to move two rigidbody objects simulataneously?

basically i have a parent with a rigid body2D component

and its child which also has a rigidbody2D component

what is a good way to move both of them at the same time once i apply a force?

[timid dove]

Just call Destroy on them both

they will both be destroyed at the end of the current frame

[wind meadow]

how does that move them?

either that or you're trolling me and telling me subtley to not even attempt that

[timid dove]

move them?

Did I misread

I thought you said destroy..

did you edit it 🤔

If you want them to move together you either destroy the child's rigidbody or make the child's rigidbody kinematic

OR attach them with a physics joint

[wind meadow]

ah ok

no i didn't say destroy pre nor post edit

but i guess glad you weren't trolling

[timid dove]

ah sorry idk guess i'm going crazy lol

my bad

[wind meadow]

it's kewl

it works

TYSM

[left plank]

I have an object I'd like to be triggered by entering in contact with a trigger collider, but not the other physics-based colliders

if I send it to another layer, both get disabled, which isn't the effect I want to pursue

is there a way to work around this or should I refactor my script for it to target a child object that would carry the trigger itself?

[timid dove]

Use layer based collisions or just disambiguate by tag or component in the OnTriggerEnter method

[left plank]

it's in fact the case. i have a OnTriggerEnter() method with tag comparisons and identifying the right collider, but that one gets disabled too if the layer of collisions is disabled

the problem being that the physics interact badly with another object, but that same object does need to get the trigger

so I guess that making a child to hold the trigger collider at the same position and tweaking the script to work with that would be a reasonable thing, but i wondered if it was possible to fine tune it for it to ignore one collider but not the other

[timid dove]

I'm not totally sure I'm following you but everything can usually be solved with an additional collider on a child object on a different layer

[left plank]

i think we're saying the same thing. my bad i kinda suck at explaining things clearly

[slow vine]

(Collisions are a part of physics, right?🤔 🤣 ) I am having some problems with sphere colliders...

What are the relationships between the sphere collider's actual "world" size, the value of its radius on inspector panel and it's gameObject's localScale?

So I have about 200 objects, each having its own parent object(and different scale), I need to add one sphere collider with a precise radius of 10 on every single one of them...

[normal cargo]

any tips on how should i make my enemy objects to climb / jump over small obstacles that are in front of them?

should i make trigger box in front of them, and that would cause them to increas velocity upwards?

or am i doing something totally wrong here? i am using sphere collider for the round enemies, and box collider for the cubical enemies

on the image, only 2 of the green balls got over the obstacle, because the other ones were pushing them from behind

[timid dove]

the world size of the collider is basically the radius * transform.lossyScale which is basically all of the scales of the object and all its parents multiplied together

the simple way to approach this is simply not to scale the parent

if you have some renderer or other component on the parent that needs to be scaled, move that renderer to a sibling object instead, and scale the sibling. Leave the parent at 1, 1, 1

[fluid lagoon]

hey i have a reglure 3d plan and a physical projectile with spherical collider

i have a script on the projectile to spawn an explosion once it hit any thing., but I keep receiving this error when it hits the plane Triggers on concave MeshColliders are not supported

[jovial wraith]

presumably your plane has a mesh collider on it and the convex button is not checked. Checking convex should fix the issue and, assuming the plane is actually flat, will not cause any other problems

[fluid lagoon]

Thanks !

[slow vine]

Got it. Thanks!

[uneven spindle]

Hello guys, can you help me solve my problem please?
I want to make my boat turn along the Y axis and only this axis but as you can see on this screen my boat is rotating along the three axis.
I used an AddTorque to make the rotation (I just used a constant value for this example to show that the issue doesn't come from my calculation).
So I don't understand why a force is applied on the other axis.

[timid dove]

AddTorque is in world space

combine that with gimbal lock, and euler angles in general being euler angles, and you get what you get

You could try https://docs.unity3d.com/ScriptReference/Rigidbody.AddRelativeTorque.html to add torque in the Rigidbody's local space

[woeful cave]

Gimbal lock sucks but quaternions... suck.

[unique cave]

Gimbal does but quaternions doesnt, they are very neat

[woeful cave]

Neat if you're a fan of CBT

[fluid lagoon]

hey, I'm debugging a trigger that is not working and I doubt that it has something to do with the collision matrIx

its similar to this image right here.

how do to enable the collision between ( Detector and water ) layers?, there aren't enough check boxes

[left plank]

my educated guess

[fluid lagoon]

thanks !!

[fluid lagoon]

hey, is the collider faster than the trigger ?

[stuck bay]

hey is this true ?

F(x) = n/x

if x -> 0-
y -> x * 10^0-
if x -> 0+
y -> x*10^0+

[timid dove]

is y supposed to be F(x)?

[stuck bay]

yess sir

[timid dove]

not enough info really

what's n

n being positive or negative matters

[stuck bay]

n is a constant

[timid dove]

the sign of f(x) depends on the sign of n and of x

[stuck bay]

nahh f(x) = n/x is the same as y= n/x

[steady bison]

Need a lil help with bike physics. I am using a bike model, and did the following:

separated wheel collider from the mesh
attached configurable joints to the mesh ones
attached rigidbody on main bike parent
ignored adding anything on chain, chassis, brakes

Is that about right for a bike, or do I need to add/change something else?

Anyway main reason I'm asking is that despite separating the two, the wheel seems to fall down anyway

I locked the motions to stop it for now

[delicate echo]

heyy im just a newbie trying to make a game so far i built something following tutorials but im having trouble with collision2denter. if anyone has experience with this please do help I need it smiling_face_with_tear

im making the chrome dinosaur game where it requires the dinosaur to jump from the ground and I have set rigidbody and boxcollider to the dino and boxcollider to the ground but when I put the code the dinosaur flies haha rather than jumping

so I set a bool variable to check if its in the air as per the tutorial but for some reason my dino jumps once and doesn't do anything else

[slim olive]

how are we supposed to know where the problem is

are you doing a ground check?

do the collisions register?

[atomic solar]

Hello, sorry, I'm not sure which chat this is supposed to go in, but I'm having an issue that the physics in my built version of my game is different to the the physics in edit mode, does anyone know why this is happening, and how I can fix it?

Play mode, not edit mode

the one in the editor

[inner thistle]

You're using physics methods wrong ¯_(ツ)_/¯

[atomic solar]

I have no idea what that means

is that to do with fixed updates and delta time?

[inner thistle]

You haven't shown your code so pretty much impossible to say

[atomic solar]

okay, ill be a sec

ive never used the new input manager or callback contexts before either, so im sure that doesn't help

i can show more if you need, but i think this is all that is relavent

[inner thistle]

And in what way is the physics different?

[atomic solar]

the jump is shorter in build mode

nevermind, it isn't, i am so sorry for wasting your time, i don't know why i thought it was

thank you for your help regardless

[delicate echo]

so the ground check is done through a boolean statement but i think the collisions do not register

do u know how to check if collisions did occur?

[slim olive]

usually do a debug.log

[unique cave]

The way quat * vector and quat * quat works is really neat. No clue how quaternions really work under the hood but quaternions are funny to work with. You dont need to know the math behind or (what x, y, z and w means etc.) to make use of quaternions

[fluid lagoon]

hey does anyone know how to solve this Math/physics issue ?

A projectile with a rigidbody component attached.
Given:
1 - the starting velocity of a projectile. (initial velocity)
2 - it has been traveling for 0.52 Seconds.
3 - it's initial position.
4 - it's position at 0.52 Seconds.

*Required: * Find the projectile velocity at 0.52 Seconds.

[timid dove]

the velocity won't change ever unless:

• it hits something
• it has gravity
• it has drag

[fluid lagoon]

the velocity certainly changes due to gravity, you can even see it on the rigidbody component that it changes slightly over time.

[timid dove]

ok that's what I'm asking you though

Are you just asking what the effect from gravity will be?

[fluid lagoon]

yes

[timid dove]

Well unity uses a discrete physics simulation

so it's simulated once every Time.fixedDeltaTime seconds

so 0.52 seconds isn't really the question it's more like "how many physics simulation steps have occurred?"

so something like:

Vector3 initialVelocity = rb.velocity;
float timeElapsed = 0.52f;
int numberOfFixedUpdates = Mathf.FloorToInt(timeElapsed / Time.fixedDeltaTime);
Vector3 changePerFixedUpdate = Physics.gravity * Time.fixedDeltaTime;
Vector3 totalChange = changePerFixedUpdate * numberOfFixedUpdates;
Vector3 final = initialVelocity + totalChange;```

[fluid lagoon]

Thanks I'll give it a try.
I was thinking something simpler like: Vfinal = Vnow + (Physics.gravity * Time.fixedDeltaTime)

but I think you are more accurate, mine doesnt make much sense leaking the number of fixed updates

[narrow solstice]

i added bounciness to my projectile but now it doesnt interract with things it has code for

[teal marlin]

Hello, trying to calculate AngularVelocity without the use of a Rigidbody by comparing previousRotation to currentRotation and adding it to the currentRotation as a quaternion when not tethered to the object, but if I face the opposite direction i.e 180degree camera movement, the deltaRotation isnt applied as intended, what can I do?

for reference

[spark zealot]

im trying to figure out how to put gravity in any direction. so if for example, an arrow was pointing in a certain direction, say its rotation was 30°, 50°, and 70°, how would i change gravity towards that direction?

[tender gulch]

Get the direction vector. Set Physics gravity to that direction.

[slim olive]

is there any reason Physics.OverlapBox would fail to return any colliders even when it's called at the same position as the collider i'm checking?

I'm experiencing some sort of bug

I'm not passing any layer mask btw

basically it returns a collider the first time the object is enabled
I disable the object
then check again for a collider but it doesn't return anything

[uneven shore]

is there an easy way to create collider for inside collision? e.g. I want an object to be enclosed inside a circle, so I was hoping to use a circle collider.
But it automatically being pushed out since the colliders are "filled".

[timid dove]

EdgeCollider2D

[modern merlin]

dynamic friction adds a force opposite to velocity with magnitude of the parameter?

[timid dove]

"the parameter"?

[modern merlin]

the number you set

[timid dove]

dynamic friction is like:
a = area of contact patch
c = coefficient of dynamic friction
n = normal force
f = a * c * n

[modern merlin]

which one of these do you set in the material

c?

or f

i mean documentation says "feels like" i want to calculate it

also it says 0 to 1 while i can go 0 to inf in the inspector

[stuck bay]

my main collider is resizing at runtime, any way to stop that?

[timid dove]

C

The others are circumstances of the contact between the objects

[stuck bay]

I need help to animate my character

[lapis fossil]

meaning

?

[stuck bay]

#🏃┃animation

[lapis latch]

Why is implementing a simple jump this hard?

should I just ditch Character Controller and return to Rigidbodies?

[merry sleet]

Hello! Sorry for what seems to be a stupid question, but I cannot really get my head over this. I've managed to do this easily countless other times but in Unity for some reasons I'm definitely struggling for something so simple.
I'm trying to build a small 2D simulation and code-wise, everything is working kinda fine. I'm against a very big issue, though, with collisions.
Plainly speaking, I can't get any kind of wall collision working.

• I've checked collision layers/and collision matrix; they're all fine.
• My main rigid body is set on dynamic.
• The wall I've tried both with/without a rigid body (and was set to static) and it has a collision.
• none of the collisions are set on trigger.

I've tried looking up online and doing exact same things but for some reasons it does not seem to work for me; once the main body "player" walks, it just moves through the wall object.

I've tried using OnCollisionEnter2D to debug if they were actually seeing each other and they do.

That's it basically, I have no idea why my player just walks through walls.
Sorry again for the very basic question but I can't really find any working solution.
thanks

PS: I'm moving my character position through code

[lapis latch]

this might be a stupid question as well but, do the walls and the player have colliders?

[merry sleet]

Yeah.
I was thinking that perhaps they do not work as I'm setting my position through code?

[lapis latch]

is the position of the wall fixed?

[merry sleet]

Yep

[lapis latch]

unfix it and try again, if the wall moves you will at least know that they are colliding properly

I would suggest you to use character controller as it handles this stuff by itself and rather easy to use but I since I am trying and failing to make my character jump with it, I am not sure if I can make such suggestion

[merry sleet]

Ok actually I think I've managed to make it work, the issue is I was using

SetPositionAndRotation()

to move my character as I was using some acceleration and steering. I'll try to see if I can manage to implement the same effect without using it.

Thanks man

[lapis latch]

I was gonna write "I am a newbie as well so this is the extend of what I can suggest"

[merry sleet]

actually you kinda gave me the idea that it could be that, so thanks 😂

I'll also check this CharacterController, perhaps it will be helpful

[lapis latch]

I am glad one problem is solved at least 🥲

It seems quite useful for some purposes but jumping might not be one of them 🙃

[merry sleet]

Luckily my ants do not need that lol

Have you tried checking this? It speaks about jumping
https://docs.unity3d.com/ScriptReference/CharacterController.Move.html

[lapis latch]

yeah

I tried to copy the code in my script as well

controller.isGrounded doesn't seem to be working consistently

even weirder part is that when the character manages to jump, the jump height isn't consistent either

which might be related to isGrounded's inconsistency

[merry sleet]

Mmh

[lapis latch]

"A CharacterController is not affected by forces and will only move when you call the Move funtion. It will then carry out the movement but be constrained by collisions." it says

maybe Character Controller just isn't fit for a platformer or anything that isn't some sort of a strategy game?

for games that is

[merry sleet]

To be honest I'm not entirely sure as I've never used it and I would not like to mislead, but from what it seems, it seems to be capable of being used in a platformer, though I'm not sure.

[lapis latch]

the TPS tutorial I looked up was using it so I assumed it would be the "right way" of doing things

anyways, since nobody is here, let me ask it on #💻┃code-beginner to see if anyone has a solution over there

[hallow charm]

My suggestion is always to avoid using the ready-made controller

Write your own, since it means you will have control over what the different things are doing.

[lapis latch]

Shortcuts complicate stuff huh?

thanks for the input

[jovial wraith]

You should make sure you always pull the CC downward via gravity when standing on the ground. If it moves directly parallel to the ground, it may not collide with the ground, which could cause the inconsistency.

You could also try using the collision flags instead of isGrounded. I'm not sure whether they'd be more reliable, but it's a thing to try.

Finally, you can always implement your own ground check with a raycast or extra collider or OverlapSphere.

[lapis latch]

thanks

I ditched Character Controller and working with Rigidbody, which works fine for most purposes but I am not sure how I can prevent the character from sliding now

Finally, you can always implement your own ground check with a raycast or extra collider or OverlapSphere.
I should've looked into raycast maybe

[rose jolt]

i am having issues with gravity not applying on the chain and the hinge not moving,

[lapis latch]

isKinematic prevents the gravity part

[rose jolt]

thanks but

it went crazy now

[lapis latch]

this video explains it very well but in short, isKinematic prevents any force on the object that isn't specifically specified by the object's script so you need to add the gravity with script
https://www.youtube.com/watch?v=e94KggaEAr4&ab_channel=iHeartGameDev

you should probably watch the video instead of reading my half-assed explanation

[jovial wraith]

isKinematic will make it ignore the joint completely. They just won't work together.

Chains are pretty hard to make. Make sure your colliders are not overlapping. That's probably why it is immediately exploding

[rose jolt]

thanks, is there a way to create a chain with 2 ends where 1 end is controlled by the player on the other is anchored?

[jovial wraith]

Make the end links isKinematic and the middle ones dynamic

[lapis latch]

Don't ask me, I barely know how to use AddForce 😦

[rose jolt]

thanks

[lapis latch]

any easy solution for this?

or should I just go for the hard math?

which I can do, I just don't want to bother

gotta go walk the dog now but I would appreciate any advice

[jovial wraith]

Character controllers in general are a whole can of worms... Hard to give much advice without getting all the details of what you're doing now.

Upping friction might since sliding. Making it all kinematic and moving it exactly how you want it to move is probably best, though. Dynamic rbs are really for physics based games. Think Angry Birds or Moving Out or Human Fall Flat. Precision platformers really need a kinematic solution

[rose jolt]

i made a bigger chain loop and i don't think they are touching in scene mode and they are going less crazy its still not smooth do i need to limit the hinge or something?

i have seen a video of a chain of 3d balls with 2d images connected to them but i don't think it will look good close up in VR

[rose jolt]

it works i just need ti figure out code to stop it from over extending because that's when it freaks out

[lapis latch]

I am only trying to get accustomed with Unity in general since I don't know what I should do after completing the junior developer pathway I decided to make random prototypes

for this prototype I am making a generic TPS

[modern merlin]

so if i add rigidbody component with gravity to an object, it will fall flat according to its center of mass. but if i change object's scale it will fall on its side. how do i make an object with changed scale fall flat?

[lapis latch]

this is highly dependant on the object you are talking about

Well, ignore what I am saying since I am only thinking about the actual physics and not about programming. There might be a solution that works with all kinds of shapes for all I know

If you don't want the object to rotate at all you can freeze rotation on the specific axis for example

[tawny dragon]

Hey guys, I'm making a 2D top-down tanks game, and after making a pretty cool custom movement controller for the tank, my next step is handling collisions but I am at a complete loss at how todo it so that my movement stays accurate as I made it. I know the way to go with heavily precise custom movement controllers is a Kinematic Rigidbody2D, but that doesn't cover collisions with other static or kinematic physics objects. Using a dynamic Rigidbody2D makes my movement have momentum even after I set the friction to 100k, which isn't at all my wish, what do you guys recommend I do? Personally I have no idea on how to make a custom controller that accurately supports collisions and such

[tawny dragon]

My script already handles momentum and even has a custom property to control how good the tank's breaks are

[timid dove]

Using a dynamic Rigidbody2D makes my movement have momentum even after I set the friction to 100k, which isn't at all my wish
You can write code to do anything you want. You can set velocity directly whenever you want, add forces whenever you want, etc. Friction is not the only way to slow things down.

[tawny dragon]

Hmm, so instead of using MoveRotation or MovePosition, overriding the velocity and angularVelocity I should get the desired effect?

[timid dove]

There are many ways you could get the desired effect.

[normal cargo]

if you want to get rid of momentum, i think you can just code it. when you are not pressing any movement key, you can force the rigid bodys speed to 0 ?

[magic needle]

@safe plover (Replying here because its more physics related)
Here is the tutorial I used to learn active ragdoll part of the character : https://youtu.be/-pX-PobRLzk

[safe plover]

awesome thank you

[rose jolt]

is there a way i can make the kinematic last chain link snap to the claw hand after the physics are applied or something of that nature? if i used a position constraint on the last chain link it disconnects from the rest of the chain

[soft glade]

Hello, started to work with wheels.
Trying to emulate Top Gear Rally's suspension and car behavior, but wheel colliders weren't behaving as desired and don't know how to tweak the settings to fix it (it drifted hard enough to turn the car 180 degrees, bounced too slow, suddenly bounced while turning and made the car fly away, etc)

Decided to make my own wheel collider using two cubes and one sphere with a wheel model:
-cubes connected, one above the other, by spring joint and configurable joint keeping movement in one axis.
-Sphere connected to bottom cube with hinge joint.

The suspension is connected to the car through a fixed joint on the top cube.
Suspension is acting closer to desired, but got an issue when trying to test movement:

Anyone who could happen to know how to go about fixing that?

[soft glade]

Clarification: used input to make the wheels apply torque and move the car forward. This for some reason makes the suspension object start bouncing back and forth, until it escalates and cascades into that.

[timid dove]

could just be a classic unstable fixed timestep spring simulation

or it could be a bug in your code

hard to say which

[soft glade]

There's no scripts on the suspension, only a playerController script applying torque to the spheres.
I suppose timestep might be the issue in that case, but how do I fix that? Never touched timestep settings.

[warm slate]

Ok this is weird. Not sure where to put it. We have debugged a mesh for render calls. But after all was said and done we found out a Configurable Joint is adding 16 draw calls even as an empty game object. URP project in VR. But I think either way Physics should not add draw calls right? Am I missing something?

[timid dove]

is it from a gizmo maybe>

[warm slate]

Is in the camera view at runtime. Would there be a way to test that? I have gizmos off. I am going to be testing on an empty project

[timid dove]

gizmos off. Maybe scene view closed entirely?

[warm slate]

Oh it is the gizmo. I see it now. I never realized it was drawing in camera view

[cedar charm]

bruh??? I just copy pasted my unity project for versioning purposes and suddenly new copy of unity project is having wild torque difference...?

the part where I apply torque is way more intense

yet all variables are same

wtf

[timid dove]

most likely you have framerate-dependent code

[cedar charm]

dont think so... plus hardware is exactly same

i used fixedupdate in few places indeed

i literally placed 2 unity projects on my screens now

one of them has some crazy torque rate with same variable

other one has normal torques

[timid dove]

doesn't mean much. It's still possible to write framerate dependent code with FixedUpdate

Show your code

[cedar charm]

nvm about fixedupdate, its a single run function

rb.angularVelocity = new Vector3(0, 0, turnForce);

one unity project has normal, other one has x50 torque at this moment

[timid dove]

well you're not using torques at all

where does turnForce come from

[cedar charm]

yeah, just angular velocity

[timid dove]

and where does this code run

etc

[cedar charm]

its fixed public variable i set from inspector (both same)

[timid dove]

share the whole script ideally

[cedar charm]

i tried goggling "vsync" check on both instances of unity

same stuff

😩

toggling*

[timid dove]

Did you mess with time scale?

check

[cedar charm]

i did not. where can i see it?

[timid dove]

project settings -> Time

[cedar charm]

not me.. but maybe some files went wild, checking

[timid dove]

also your code could change it

[cedar charm]

same exact in both windows

hmm nope.. only time i messed with "time" at all was simple time.detlatime stuff

[timid dove]

show your whole script?

[cedar charm]

eh its a mess, hastebin?

[timid dove]

yes

also are you using version control? (you should)

if so you could easily detect any differences between the two

Doing a print($"Turn force is {turnForce}"); is not a bad idea either

[cedar charm]

https://hastebin.com/ozinicowep.csharp

anyways uh

both in scene

and in play

my "turn force" is manually 200

not 50

in inspector

[cedar charm]

yeh

this was specific case, and im just confused why it even happened.. starting to sound like weird unity bug unless you find something dumb in that .cs

Can I use github desktop to see diff?

[timid dove]

probably

[cedar charm]

i heard of those diff tools specifically tho

checking

[timid dove]

but just looking at your status

should tell you if anything changed

[cedar charm]

which one you'd recommend

for git diff

[timid dove]

you don't need a diff tool

just look at your changed files

[cedar charm]

i want to compare 2 supposedly

identical

follders

[timid dove]

You can compare each of them to the git index

by just looking at any unstaged changes

[cedar charm]

ah ye

I mean like

[timid dove]

as long as both are on the same commit

[cedar charm]

2 different folders

outside git fdolder (one of them)

one of them is outside

[timid dove]

you could have cloned it with git

instead of copy and pasting

[cedar charm]

yeh i guess

dam man its just really confusing what just happened 😄 maybe its some bug indeed

i could try tweaking values again to make them normal

i guess that'd be more sane by now hahah

i heard of project "physics" settings like gravity, maybe theres something like uh, global angular drag

but even if there is

i never touched it so wtf 😩

[timid dove]

drag wouldn't be relevant here

[cedar charm]

ye its not here

[polar leaf]

@cedar charm are the read only properties of the rigid body different in the editor? (Like the inertia tensor stuff)

[cedar charm]

i think it was, but only to do with the fact that I raised the physics applied object to see if it could be colliders freaking out

i solved it all by having to manually adjust the variables of applied torques etc

but crazy what just happened lmao, must be some sadistic bug in unity or my brain

in one of those situations i just freak out about "Wtf is even going on" not "ok how do i fix this then"

which isnt good i guess

and by "i think it was", i mean this field only

[nova tangle]

Was working on GPU instancing and procedural island generation and now my physics dont work... or atleast no gravity is applied to this cube or anything, which i only setup for this purpose.

My physics works in other scenes, just not this procedural one.

I feel like i've tried everything:

- Gravity in settings is set
- Cube not colliding with anything
- Moved the cube faaar away from anything
- No constraints
- Rigidbody is not asleep
- Restarted Unity

Dont know what else to do

[timid dove]

Time scale?

Physics.autoSimulate?

[tired cape]

Hello friends, I have a question regarding 2d point effectors/2d gravity… hopefully someone can help , any information is appreciated…

Basically, I have a script that I made that I then found out does the same thing (basically) as a 2d point effector. This is like, a top down space ship and there are planets with gravity that of course have an effect on your flying, however, when I exit the range of influence of the planet my ship continues to fly off as if there is a constant force being applied to it, seemingly in the direction that the ship exited the planets range of influence. In my project settings I have 2d physics gravity on x and y axis set to 0, idk if that has any effect on what I’m doing or not but I figure I should add that. Even if I fly in the opposite direction of the mystery force (like you’d have to to slow down in 0 gravity), as soon as I let go of my move forward key, the mystery force is still applied.

I’m new to Unity and coding so this is likely a simple fix… but I’m not quite sure what it could be

[tired cape]

I did a quick screen recording in hopes of demonstrating what's happening. https://youtu.be/GNMn-j_C_fk

Ignore the channel name lol

[graceful star]

Hey yall, I have spent upwards of ten hours trying to get the following to work with very little success.

I'm developing a virtual reality nursing simulation on the Oculus Quest 2. The patient in my simulation is a baby, and one of the capabilities of this baby must be that it is able to sit up (from laying down) when the player pushes the back of the baby. To accomplish this, I made use of a hinge joint, which did exactly what I wanted.

Later, I was required to add a RigidBody to the root GameObject in the baby's GameObject hierarchy, which began the onslaught of bugs I have since been dealing with. The following is a screenshot of the GameObject hierarchy for the baby:

The RigidBody is on the root (titled "Baby"), and the hinge joint is on the pelvis (which contains the torso, head, arms, etc.). Initially, both legs were also children of the pelvis, but in order to have the pelvis/upper body rotate independently from the legs, I had to move the legs to be siblings with the pelvis instead. Unfortunately, in doing so, the baby's legs now flop around whenever someone makes contact with them. And not only do they flop around, but they get flung reasonably far away somewhat randomly after pushed around a little bit, and just behave in a generally strange manner.

What is my solution here? I need the RigidBody on the root "Baby" GameObject, I need the Hinge Joint on the pelvis, and I need the legs to be outside of the pelvis in order to facilitate appropriate bending at the hinge.

Any suggestions are highly appreciated!

[open parrot]

hey! I have a question on using Rigidbody component.
I have a player and a cube, both has rigidbody and collider component. whenever i move the player near cube, player slide and stick to cube. when i try to move back the player starts vibrating, then if apply more force then the player starts moving back. I dont want my player to stick to the cube.

can anyone help me with this?

[nova tangle]

Already checked time scale, and why would it be autoSimulate if it works in other scenes?

[nova tangle]

Bump on this :-)

[timid dove]

How did you confirm the Cube is not colliding with anything?

[timid dove]

Just checking off the possibilities

[nova tangle]

I found the issue... It is a very odd one, but i got it. I am working with networking. but for testing i just setup a single player scene (absolutely no networking in the scene). But for some reason it does not run physics-calculations without the network manager in the scene... Very odd. But thank you anyway for trying! It's very nice of you.

[timid dove]

Yeah because the networking library probably turns off auto simulation

Which is why I asked

[nova tangle]

Makes sense. Thanks man <3

[molten tangle]

Hello I made a elevator using animation, the problem is when I get on the elevator it goes up but my player controller remains at the place where it was standing. Even though my elevator has collider why it just go through me how can I solve this?

[high spear]

I suggest move your player as child of the elevator game object

[molten tangle]

What that exactly means, you want me to put my player controller as a child of elevator object, is that even a solution?

what if I tell you there are 8 elevators !!

[inner thistle]

When the player steps on an elevator, you make the player a child of that specific elevator. When they step off you unparent them.

[high spear]

yuppy, you can use transform.parent

[molten tangle]

It still doesn't work, controller stays where it is, even when I put my controller as a child of elevator in hierarchy

private void OnTriggerStay(Collider other)
{
Debug.Log(other.name);
if(other.name == "XR Origin")
{
other.transform.SetParent(gameObject.transform.parent);
}
}

[high spear]

I assume one of those two gameobjects have a RigidBody?

[molten tangle]

Okay now everything works fine, there is one issue only, when ever this code runs my XR Origin becomes child of Lift Manager I want it to become child of Lift GameObject

This script is on Lift GameObject not on LiftManager GameObject, but still it makes my XR Origin child of Lift Manager

Okay the error was in the code it's

other.transform.SetParent(gameObject.transform);

[high spear]

I think its should be other.gameObject.transfrom or other.gameObject.name

[molten tangle]

It's working fine now but there is a problem as I reach 1st floor and start moving player controller fells down why is that

[high spear]

is the movement of the game object elevator going up is handle by the animator?

[timid dove]

why are you setting the parent to the elevator's parent and not the elevator itself

[molten tangle]

Yes it is done through animator

[molten tangle]

I did that in the starting, I corrected that mistake now I make it child of elevator

[steep bison]

is there a way to change the grid snapping size for box colliders?

[warm pilot]

I have a chain of ArticulationBody elements. If I ArticulationBodyHead.SetJointPositions how do I force an update to get the transform of the tail? Right now the tail's transform is unchanging.

    private void SetRandomReachableTarget() {
        SetRandomPose();
        SetTargetToPose();
    }

    private void SetRandomPose() {
        for (int i = 0; i < targets.Count; ++i) {
            targets[i] = Random.Range(-1f, 1f) * 180.0f;
        }
        Debug.Log("targets=" + string.Join(",", targets));
        bodyHead.SetJointPositions(targets);  // must be in degrees

        for (int i = 0; i < targets.Count; ++i) {
            targets[i] *= Mathf.Deg2Rad;
        }
        bodyHead.SetDriveTargets(targets); // must be in radians
    }

    private void SetTargetToPose() {
        Transform eet = bodyTail.transform;
        target.transform.SetPositionAndRotation(eet.position,eet.rotation);
        Debug.Log("p="+eet.position + "\tr="+eet.rotation);
    }```

[torpid marten]

Quick question, do mesh colliders use ressources on their own, or only if theres some rigidbody who would be effected by it? Would make a huge scene with hundreds of colliders be any less performant than a scene with one mesh, if theres only one rigidbody in both?

[timid dove]

try it and let us know

[keen lynx]

Does anyone know offhand if an AABB is always aligned to its original coordinate axes, or if it inherits from its parent object? For example, if I rotate the parent object, will that invalidate the AABB?

[bleak umbra]

what do you think AABB stands for

[keen lynx]

Axis Aligned Bounding Box. My question is: which axes?

The documentation just says "aligned with coordinate axes"

[bleak umbra]

those are world axes

there are no other axes, the local ones are virtual

[keen lynx]

That makes sense! Thanks for the clarification.

[timid dove]

The whole point of AABBs is that they use the world axes to make bounds calculations extremely fast

It's very easy to tell if a point is inside an AABB

For a rotated box, not so much, the math gets much more complicated

[keen lynx]

I understand, I just didn't understand the nomenclature of "coordinate axes". I thought maybe they were checked against their parent transform. But I get the whole thing now, it was cleared up.

[eager berry]

Hey, so I have this rigidbody boat that is floating on water, I'm having trouble when my player is trying to stand on this boat. I can't seem to get the boat not to be affected by the players velocity and so the boat just sinks whenever I stand on it. Anyone know a way to get my player to not affect the rigidbody's velocity?

[viral ginkgo]

@eager berry Make the boat heavier

And also scale the forces on the boat with its mass

[timid dove]

the cheeky way is this:
Make a child object of the boat:

• give it a kinematic Rigidbody
• give it a non-trigger collider that rests at the top of the boat.

This child is the surface your player will stand on

The player will have a platform and the boat should be unaffected by the player

[eager berry]

thank you so much! the only problem with this is that my player kind of sinks into the ground and stutters back upwards. Do you know any way of solving this?

[timid dove]

make sure you're actually only moving your player in a physics-friendly way.

the boat too

[desert wharf]

hey i need help. Whenever i have my scene window next to my game window and start my game. the player which is based on a rb flies up when i am facing a specific direction. but when i pull the game window out of the unity editor everything works fine

why?

[timid dove]

no idea you'd have to share code etc.

[desert wharf]

i dont think it has anything to do with code, but maybe i can show some footage

can i pm u ?

nvm i think it has to do with it

[timid dove]

what makes you think it doens't have to do with code?

[desert wharf]

wait, so its like this. there is a specific direction and if i walk towards it, after like 0.5 seconds i start floating

[desert wharf]

i tried something but it wasnt rifht

right*

ill share the code

if you dont understand certain things i can try to explain it to you

[timid dove]

please share via paste site as per #854851968446365696

[desert wharf]

one second

https://gdl.space/izufisecux.cs

like this?

[timid dove]

yes

[desert wharf]

do you know why this happens?

[timid dove]

not yet lol

My brain's also kinda fried from the workday so I kinda opened your script and my mind went blank

This seems a little sketchy though:
rb.velocity = new Vector3(limitedVel.x, rb.velocity.z, limitedVel.z);

[desert wharf]

haha can relate, im just very courious what the reason could be XD

[timid dove]

Should the middle one be y?

[desert wharf]

omfg

THXXX

Ill try out

its working

thank you very much

can i ask u something?

[raw lark]

I need to calculate how long it would take to zero-out an angular velocity. I've got a simple spaceship model where different ships have different characteristics of how much torque force they can apply each second, up to a certain maximum rotation speed for the ship. I've got AI turning to face a certain position but at some point before it reaches that direction it needs to start counter-steering so the ship ends up facing the target, hopefully all as snappy as possible. I think I have a very basic handle on inertia tensor, mass, angular dampening, but I can't quite visualize how to put it all together.
Any help, guides, examples, comments or terms I should be searching for?

[timid dove]

If you just use ForceMode.Acceleration or VelocityChange the math is greatly simplified

[spark zealot]

ive been trying to limit my movement speed in any gravity. currently, i just have limiting the speed by getting the magnitude of the velocity with the y value removed, and if the magnitude is greater than a max speed variable it sets it to the max speed. that works completely fine for up and down gravity's, but for gravity's like left and right, forward and back, and any other direction, it doesnt work at all. ive been doing research for a few hours and i cant figure it out.

[urban geyser]

I'm trying to make a 3D snowmobile, I'm using wheel colliders but as soon as I go a little bit too fast it has 0 grip and drift a lot, how can I increase grip?

The "wheels" at the rear make the sled move

[tropic nexus]

This seems like such a simple issue I cannot get it to work.
I have a 3D game where the player is able to carry objects.
HOW do I make him carry objects such as his movement speed/force affects the object he is carrying?

I tried fix joints but then the player can fling himself upwards with the object.
I tried spring joints but even with very high spring force the object lags behind and wobbles.
I tried moving the carried object with rb.MovePosition but that is buggy when encountering static walls as it always tries positioning itself inside it so it just vibrates in place.

Can someone point me in the right direction?

[timid dove]

The concept is correct but you have to just use vector projection to find the component of velocity orthogonal to the gravity direction

[timid dove]

you want his movement speed to affect the object, or the other way around?

[tropic nexus]

Basically if a BIG player is holding the object I would like the object to be moved with larger force.

I have 2 different sized characters and I need their weight/force to affect how they can manipulate this object

[timid dove]

but is the player's movement ffected by the object at all?

[tropic nexus]

I need to prevent the smaller player character from being able to push around obstacles that would normally be too heavy for him with just holding an object

[tropic nexus]

No. Does not need to be at all

[timid dove]

so can't you just make the object kinematic and set it as a child of the player?

And just do a mass check before picking it up

[tropic nexus]

Not picking it up. Thats not the issue. But hitting other objects with the held object

If you use things like rb.MovePosition or transform.translate you can fling dynamic objects like baseballs with just turning around while holding an object

I also dont want any visual syncing issues. So the held object should stay in place and not lag behind when turing around for example

[timid dove]

MovePosition will do that yes. Translate will not

I tried moving the carried object with rb.MovePosition but that is buggy when encountering static walls as it always tries possitioning itself inside it so it just vibrates in place.
This should not be the case

I think you were probably doing something a bit off there

can you show the code you had for that?

[tropic nexus]

How is that not the case when you try to move a dynamic object into a static collider every frame? What should happen according to you? It makes sense it happens.

It was either that or movement without interpolation which looked even worse

[timid dove]

the physics engine detects the collision and only moves the object as far as it should go without them overlapping

the problem is if you are doing that every frame and you are doing it with transform.Translate for example, yes you will get penetration

it works properly if you move via the Rigidbody in FixedUpdate

[tropic nexus]

Does not matter anyway as it does not do what I want

As it will ignore the characters mass when being moved and not slow him down when pushing another object

[flint anchor]

how do i make my character unaffected by the environment? sometimes if i hit a wall weird my player will spin. character has a rigidbody and capsule collider, and room has a mesh collider

[bleak umbra]

generally what people do to get their characters under control and prevent "weird" things is to not use a rigidbody (or rather physics system collisions and forces) for character movement

[flint anchor]

i used a rigidbody cuz i want him to push stuff that he touches or interact with other things

[bleak umbra]

you can do that with a kinematic controller too

[flint anchor]

can a kinematic controller roll and go upside down

[bleak umbra]

it can do whatever you program it to do.

[flint anchor]

okay i must have been thinking of something else then

[verbal jolt]

I'm doing the Counting Prototype tutorial and I'm basically trying to get a box to move back and forth to collect balls. However, the balls keep passing through the walls of my box. I applied a rigid body to the balls and set collision to continuous, but no luck. any advice?

[timid dove]

It's not enough to just slap a Rigidbody on them. You need to actually move them via the Rigidbody

[verbal jolt]

what do you mean?

[timid dove]

As opposed to teleporting them via their Transforms

[verbal jolt]

they're spawning in the air and falling into the box. When I move the box, they pass through the walls instead of staying inside the box

[timid dove]

ok but how are you moving them and/or the box? That' what I'm talking about

[verbal jolt]

I think I understand what you mean and changed the movement of the box to AddForce. The balls are staying better, but not entirely. If I move one direction at top speed and change direction, they go through. Also, when I get to 3~4 balls, they start falling through the bottom

nvm, changing the mass of the balls seems to have fixed it. Thank you for your help @timid dove 👍🏼

[tranquil thorn]

hello

https://issuetracker.unity3d.com/issues/moving-gameobject-with-box-collider-component-gets-stuck-on-the-corners-of-other-gameobjects-with-box-colliders

this is exactly the issue im having

it's getting stuck on the collider like that

and if i unfreeze rotation, it goes all over the place

thing is, I want to keep my player a flat rectangle

is there anyway to workout around it? I don't know how to do the thing with linear force described in the link

[bitter void]

How do I get the angle between 2 points?

[bleak umbra]

There is no angle between points

if you mean directions, you can use Vector3.Angle(a, b)

[bitter void]

I have 2 Vector3s, need the angle between them

Vector3.Angle doesn't seem to be giving me the correct result

[bleak umbra]

You need to be more precise about what you want

[bitter void]

@bleak umbra

I have a thin long cube, and 2 vectors. I need to rotate it such that it looks like this

[bleak umbra]

cube.transform.forward = b - a

cube.transform.position = (a + b) / 2

[bitter void]

I can lerp this, lerp works fine

[bleak umbra]

this assumes the cube‘s long axis is z

[bitter void]

got what I wanted, thanks @bleak umbra

[limpid quartz]

Hey people. Been working on a project for about 3 years, yadda yadda etc!

Does continuous collision detection actually work? I have an extremely simple setup where a rocket or bullet gets fired out and should always collide with the wall

And half of the time they just seem to completely clip through

Is it completely broken, or am I doing something wrong? I'm not moving these via script, they simply receive AddForce(force, ForceMode.Impulse) when created. Their transforms aren't changed manually or anything like that

They're obviously quite small and fast-moving projectiles

[timid dove]

Continuous collision works but it's not perfect, especially if both objects are moving and the smaller they are and faster they are the less reliable it is

[unique cave]

both doesnt even need to move as seen here (both are dynamic tho). discrete physics engines are quite bad at resolving large forces from many sides of the object at the same time

[merry sleet]

Hello! I'm getting some issues with my raycast reflections in 2D and I hope someone has any idea why this could happen.
Basically I'm using a raycast to detect some collisions for my simulation, though there is an issue with my normals and reflections whenever I try to use them in order to "find" the new direction of my entities.
As you can see (hopefully, drawing aint the best lol), the yellow arrow is my initial direction;
now, most of the times I get the supposed result of a reflection, which is the green arrow. (I calculate that using Vector2.Reflect(incomingRay, hit.normal).
Sometimes, though, especially in situations like this one, the reflection happens to be similar to the red arrow which I completely cannot understand me being stoopid.
Here's my code and thanks if anyone knows what it could be.

        RaycastHit2D hit = Physics2D.Raycast(position, new Vector3(velocity.x, velocity.y, 0f), 1.0f, 8); //8=3=walls

        if (hit.collider != null)
        {
            Debug.DrawLine(position, hit.point, Color.yellow, 10.0f);
            Vector2 fromTo = hit.point - position;
            Vector2 reflection = Vector2.Reflect(fromTo, hit.normal);
            Debug.DrawLine(hit.point, reflection, Color.red, 10.0f);
        }

[timid dove]

your raycast is probably hitting a different object than you expect. Print out the name of the object you hit?

Wait also your DrawLine is not correct

the second one

[merry sleet]

I'll try though there are no other objects in the area that could impact the hitray.

[timid dove]

That should be a DrawRay since you're using a position and a direction instead of two positions

reflection is a direction vector

[merry sleet]

I shall try now, thanks.

Ok so it seems to kinda be working but still have some issues similar to that one. I'm starting to think it might be because there are too many updates and as my entity is still turning, the ray finds another direction to move on, and doing that every frame somehow seems to fuck it up a bit.
I'll try soon to reduce the frequency of the updates and write here if I still find issues.
Thank you!

[desert wharf]

hey everyone, i need help. I want to create a shooting mechanic in 2d. I have a weapon and a Guntip to fire from. the guntip gameobject is a child of the gun, so the position doesnt change. I dont know how to get around that.

[timid dove]

the guntip gameobject is a child of the gun, so the position doesnt change. I dont know how to get around that.
The position certainly does change

as long as the gun moves

the tip will move too

don't be confused by the position numbers in the inspector not changing. That's the local position

[desert wharf]

hey thanks for your answer

[timid dove]

but you should really do this btw:

GameObject tmpBullet = Instantiate(bullet, gunTip.position, gunTip.rotation);```

and you don't need the second line

[desert wharf]

wdym

[timid dove]

you can spawn an object at a particular position, you don't need to set the position in a separate line

[desert wharf]

ah yes

i fixed it already but i have another question

[desert wharf]

how can i rotate the tmpBullet around the z axis?

after instantiating it

[timid dove]

what's the goal?

rotate it in what way

where do you want it to point?

[desert wharf]

wait let me explain

ill send some pics

basically this is the layout, a square with a gun, and at the tip of the gun the Bullet will spawn

[timid dove]

ok and?

What about the rotation?

[desert wharf]

but i need to rotate the bullet another 90 degrees, so it points to the mouse

[timid dove]

where's the mouse?

Why 90 degrees?

[timid dove]

this code I gave you will already give the bullet the same rotation that the gun tip has

[desert wharf]

wait a sec

[timid dove]

all you need to do is set the gun tip to be rotated the way you want the spawned bullet to be rotated in the editor

[desert wharf]

rn the bullets go in the wrong direction

[desert wharf]

ill try wait

thanks it works

have a nice evening ^^

[summer sentinel]

i dont think this is physics related but this is the most fitting channel for my problem.
i have a capsule collider for a player and whenever i start the bottom part clips a tiny bit into the ground when it falls, meaning that after it falls enough of the collider is inside the ground which causes the player to get stuck and clip.
for the floor i am using several planes.

nevermind, i found the problem

[frank shadow]

Hey guys. I'm trying to make one way platform on a tilemap using platform effector 2D. It's working as intended besides when I'm running. As you can see the player gets stuck on the next tile. Does anyone know a fix for this?
https://gyazo.com/23a9856227801793eebbbe0c641b4505

[paper lodge]

I deleted my message after testing stuff out and figuring they share the same physics scene a bit better.

I dont understand why moments ago it wasnt finding it though hmm, anyway pardon the distruption

[civic field]

The problem is getting stuck in the wall ?

Your solution will depend on how you implemented the one way platform

[plucky thunder]

should i first add gravity or drag?

[frosty ore]

@sturdy prairie finally Did it! lol,, all physics, hinges, and springs for the launch... nothing but a collider on the bolt, and a piece of script to orientate it towards its velocity direction, 3 day to get it from Kids toy image, -> blender model -> physics setup, to repeatable launch

got a 900 feet range, and that's just with the current settings, can't angle it much more but the spring could easily get some punch

[snow surge]

I feel like I'm going crazy, does it the order rigidbodies are instantiated matter when parenting to other rigidbodies?

Working on a multiplayer physics airship game, and need players to stick to the ship as it moves around, but for some reason I'm getting a very strange difference in behavior when player 2 joins and player 1 is already on a ship.

Option 1 works perfectly when the player spawns in after the ship spawns, but makes players that existed before the ship slide off in the direction of the velocity.
Option 2 works perfectly when the player spawns in before the ship spawns in, but players that spawn in afterward stay perfectly still when the ship is in motion.

// Character code

if (onGround && !isJumpOnCooldown)
{
    // Option 1
    Rigidbody platformRb = platform.attachedRigidbody;
    if (platformRb != null)
        rb.velocity = platformRb.GetPointVelocity(rb.position);
   
   // Option 2
   rb.velocity = Vector3.zero; 
}

[snow surge]

Turns out setting the ship's rigidbody to kinematic and back removes and then re-adds the ship to the end of the list, fixing the issue, but there's gotta be a better way, right?

[wraith junco]

Does anyone have any knowledge on multi-raycast suspension? Do you essentially just model the lower-half of the wheel with angled raycasts and then start at the fully compressed position, and just move that modeled wheel down until it hits something?

This topic is so dry online, hard to find anything

[snow surge]

I'd suggest having a wheel collider that represents the highest position the wheel can be, so that the raycasts don't ever start below a surface, it also stops any suspension code from hitting extremely compressed values, which can wind up sending vehicles to space.

Do you need pointers on the actual suspension physics?

[wraith junco]

Yes, that's how I did it with a single raycast. Shoots directly down starting at the fully compressed position and compression is determined based on the hit position

I mean

I just want to know how it's done

[snow surge]

That's how I've always seen it done in some variation. The wheel's collider usually doesn't actually move in and of itself, but the wheel is just a visual aspect

[wraith junco]

If I model the half wheel, and move that down, that's gonna be a pretty big performance hit

yeah that's tricky with multi-raycast suspension

since the "spring length" will be different based on different angles of the wheel

if I didn't move the raycasts up and down

[snow surge]

Are you talking about just something like this?

[wraith junco]

that actually

might be a better idea

[snow surge]

Yeah that's what I did in my project awhile ago, I just took the value farthest from the target as the suspension level

[wraith junco]

This is how I'm currently doing it

which doesn't make much sense

[snow surge]

ah I see yeah lol, since the suspension goes downwards I raycast downwards too

You can also do a sweeptest I believe

on the wheel collider

[wraith junco]

yep, sweeptest is how physx does it I believe

The photo above drives fine up rocky terrain and such, since I just get the raycast that first hit something, determine the compression, and add the force upwards. The tricky part is just determining the location of the visual wheel. Someone yesterday told me to negate the direction of the ray with the radius. Using the Y value from that seemed to work fine at non excessive angles, it just didn't feel like the right calculation for whatever reason

but yeah raycasting downward or sweeptesting seems like a much better idea

[snow surge]

Yeah the radial casts are a bit strange since suspension typically doesn't go forward and back lol, sometimes we miss the forest for the trees

[wraith junco]

yep, that's completely the problem

How exactly do you calculate the suspension length in your photo above?

Obviously it gets shorter towards the sides

Its 4am, this might be a really obvious question that I'm not seeing

[snow surge]

You just take the delta like so
float distOffsetFromBottom = maxRayLength - hit.distance;

[wraith junco]

Wonderful, thanks

[snow surge]

gotchu 👍

[robust belfry]

I am studying physics department and I am new university student now. I wanna develop physics simulation apps but I dont know how to start for learning physics.

do you advice me for learning physics tutorials with unity?

[stuck bay]

How do you cast so many rays?

[timid dove]

with a loop presumably

[stuck bay]

oh yeah

I never thought of that

thx

[wraith junco]

@snow surge How exactly do you resolve collisions with your wheel collider method? The selected spot is the first collision among all of the raycasts. I take that raycast collision point and subtract the scaled radius from it and apply that to the wheel's y position.

however, the bottom of the wheel penetrates the ground

This is how I setup the raycasts. Red is the radius scaled along the wheel and the blue is max suspension length

I think this might be a flawed way of doing it.

I'll be testing sweeps next

[undone ruin]

hi i need some help

i attacked a poligon collider to this right shin

and when i see it it also apply the collider to the boot child

also the boot has it's own collider separately

how can i make the rightshin collider to be only on the blue capsule

nvm i finnished by separating the child and make a different script

[snow surge]

What formula are you using to get the ray's target length?

[snow surge]

The forumula for ray length is sin(acos(normalizedRayXPosition)) * wheelRadius

[wraith junco]

oh, I was using pythagorean theorem to find the length

Regardless, I think I've got something working better with sweeptests

[charred lava]

So just out of curiosity... when working with Rigidbodies and Rigidbody.AddForceAtPosition, is the force additive? So if I have like 4 thrusters on the bottom of a ship and apply 10N to each one, will the applied force overall actually equate to 40N? Just trying to figure this out so I can accurately apply forces.

[timid dove]

yes it's additive

that thruster scenario is pretty much exactly what that function was made for

[charred lava]

Awesome, ty!

[lone axle]

am hello i am new in unity. Why does my character transfer collisions if I already add a 2D box collider?

[timid dove]

What do you mean by "transfer collisions"?

[uneven shore]

hey guys, I have a TilemapCollider2D and when I'm calling ClosestPoint I keep getting the same point - even though it's not inside the collider and the collider isn't disabled.

Any idea why, and on how to actually get the closest point?

[timid dove]

I'm going to lean in the direction of it's more likely there's something wrong with your setup than a bug with that function. Maybe share more details about your setup?

[uneven shore]

@timid dove I actually found the issue; apparently when there is both a CompositeCollider and a TilemapCollider2D, it's important to call that method on the CompositeCollider and not the TilemapCollider2D. Thanks though!

[distant iron]

How would you make a trajectory function?

I did get something to work but it doesn't handle rotation of the go at all (it's a plank like go) and it looks not that good

[robust belfry]

I want to make vehicle that have soft body tires. I created soft body tire and I want to add force like a wheel is rotating. I added addForce to child's Rigidbody but these tires cannot rotate and cannot move like a wheel. How to fix this problem?

[lost widget]

I'm trying to make a controller for a submarine, and I'd like the pitch and yaw of the vessel to be controlled by a torque, so that the rotation can still be affected by other interactions. I'm having trouble figuring out just how I would interpret a desired rotation into a torque that would rotate towards that rotation. I've been looking at other solutions for similar problems, and I've found the documentation for the RigidBody.MoveRotation() method, but I'm not sure that this will do what I want it to.

An example of why I think I want to use torque rater than MoveRotation would be if the vessel were to be trapped under a heavy rock. I don't want the vessel to just arbitrarily be able to rotate around and push the rock off of itself. If the torque that the vessel is able to exert isn't enough to move the rock, then I don't want it to be able to.

If anyone knows how I could approach this please let me know.

also, specifics would be greatly appreciated, as right now I'm still somewhat confused on just how I'm going to get the desired rotation, just that I'll be using mouse input to rotate around x and y axis respectively.

[timid dove]

Seems clear you'd want to just use AddTorque, no? Or even AddForceAtPosition to add oblique forces at the rudders

[lost widget]

Yes, I think so, but I don't know how to calculate how much torque I should add. I know somehow it needs to depend on a desired position but I don't know of whatever equation I might use to find that.

[timid dove]

I don't think it's dependent on any desired anything

you have inputs from the player

and they can correspond directly with torques being added around particular axes
Or at least to setting the rudder of the ship to a certain position which applies a particular torque.

You would only worry about a "desired heading" or "desired orientation" if you were making some kind of autopilot

[dense coyote]

So I have a simple game structure like this: