⚛️┃physics

[timid dove]

If you're using a 1m diameter sphere

[young rapids]

In the editor's game view, it runs perfect

[timid dove]

It seems reasonable

[timid dove]

Oh then you have some framerate dependent code for sure

Show your code

[young rapids]

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.InputSystem;

public class PlayerController : MonoBehaviour
{

    public float speed = 4;
    Vector2 relativeMovement;
    public float gravity;

    public float smoothTime = 10.0F;
    public Vector2 accelerationVector;
    private Vector2 velocity = Vector2.zero;

    private Rigidbody rb;

    // Start is called before the first frame update
    void Start()
    {
        rb = GetComponent<Rigidbody>();
    }

    private void Update()
    {

        Vector3 movement = new Vector3(InputController.movementX, 0.0f, InputController.movementY);
        Vector3 cameraMovement = Camera.main.transform.TransformDirection(movement);
        relativeMovement = new Vector2(cameraMovement.x, cameraMovement.z);
        relativeMovement.Normalize();

        accelerationVector = Vector2.SmoothDamp(accelerationVector, relativeMovement, ref velocity, smoothTime * Time.deltaTime);
    }

    void FixedUpdate()
    {

        rb.AddForce(accelerationVector.x * speed, 0, accelerationVector.y * speed);
        rb.AddForce(Vector3.down * gravity * rb.mass);
    }
}

It's every object though, even the ones that just have a rigidbody and a collider

[timid dove]

What happens if you get rid of the smoothing code there for a sec

Just set accelerationVector = relativeMovement;

Does that fix the weird difference in behavior?

[young rapids]

Just checking. In editor is fine, building real quick

[lapis plaza]

you literally factor in deltatime to your addforce there

accelerationVector = Vector2.SmoothDamp(accelerationVector, relativeMovement, ref velocity, smoothTime * Time.deltaTime);
rb.AddForce(accelerationVector.x * speed, 0, accelerationVector.y * speed);

[young rapids]

That's just for how fast the speed vector ramps up

[young rapids]

It's still slower in build, but not by as much.

[lapis plaza]

but why is that a thing in the first place?

[young rapids]

Either way, this code wouldn't effect the gravity of the other physics objects

[young rapids]

Because applying a sudden force to the marble makes it look like it's being pushed. There's a slight ramp up so it looks like it begins to roll on it's own.

[timid dove]

What's your framerate

In the build

If you're hitting the max timestep it'll actually slow down the physics simulation

Though it doesn't seem likely here...

[young rapids]

I’ll have to check in a bit, got to do something for now.

[young rapids]

Is it ok to make things real world scale, when I'm working with miniature scale stuff?

Like, the main marble being 18mm

[lapis plaza]

it can cause issues but I'd try first because drawing too many conclusions

physx kinda struggles with tiny objects, especially if you have like angled surfaces and joints etc

[timid dove]

It's ideal to make things real world scale if you want them to look and behave like they're that scale

especially if you're using physics

but also for lighting

[lapis plaza]

I learned that when doing some pinball game for game jam once...things broke in really weird ways 😄

[timid dove]

well yes if things are very small you may need to play with some of the defaults in the physics settings

like contact offsets

and yeah there's a limit

18mm is not crazy small though

[lapis plaza]

this is basically why we make prototypes and test things

see yourself if it works in real to life scale and only worry about it if you see it's causing issues

if you have to spoof the scale, it comes with extra baggage and side effect

[young rapids]

This is my main reason for wanting to. It's the reason my marble has seemed "floaty" so far

[lapis plaza]

scaling everything by say 10x isn't issue physics wise, you just up the gravity and forces to counter it

but it's still simpler to keep things in right scale if possible

[young rapids]

Would gravity scale evenly? Like, 98.1m/s2 instead at 10x?

[lapis plaza]

yeah

just like that

[young rapids]

I feel dumb for saying "When are we gonna use this" to math/physics teachers XD

[lapis plaza]

you can also do the math yourself if you want 🙂

a lot of the basic physics equations apply as is to game physics

you use newtons laws a ton here

[young rapids]

So far I have been. My marble should be 0.024 mass if it's in kilograms, based on steel density

The AO/shadows definitely seems sketchier at this scale

[young rapids]

Is there a way to work out a realistic restitution value?

[lapis plaza]

@young rapids https://en.wikipedia.org/wiki/Coefficient_of_restitution#Predicting_from_material_properties

[young rapids]

Oh boy

Ya know, maybe eyeballing it isn't so bad

[lapis plaza]

they list some estimates there

[young rapids]

Ooh yeah. Is that a 1-1 with unity?

[lapis plaza]

considering they have values over 1.0 there, I doubt it

any figure higher than 1 would start generating extra energy instead of damping the motion

that being said, their do say COR = relative velocity after collision / relative velocity before collision

so... wonder what's up with those figures then

ah

"The COR for plastics and rubbers are greater than their actual values because they do not behave as ideally elastic as metals, glasses, and ceramics due to heating during compression"

[young rapids]

It does say at the top "Values over 1 indicate an error in the estimate"

[lapis plaza]

I guess that explains it

yeah

should be 1:1 for metals then

[young rapids]

Steel is 0.9, which in unity would mean almost fully bouncy

[lapis plaza]

0.63 to 0.93

that's a lot o range still

[young rapids]

True

I'm already having physics issues in unity

The marble is just falling through the floor

[lapis plaza]

you know newton's cradle?

if you get rid of extra frictions, it will keep going for a quite long time

[young rapids]

Ahh true

How do you make icons smaller?

[lapis plaza]

heh

not a problem most would have

there could have been some scale setting for those

[young rapids]

Maybe scaling stuff would be better

[lapis plaza]

see that slider?

on gizmos dropdown

[young rapids]

Yep, thank you!

Shadow Resolution is the biggest issue.

4k is basically 128x128

[lapis plaza]

?

how is it any kind of issue

shadow resolution is relative to your shadow distance

[young rapids]

Really? I couldn't find any settings for it beyond that

I've scaled everything up and that seems fine, apart from gravity.

With realistic gravity, it's suuuper hard to climb ramps unless you're moving really fast.

[lapis plaza]

@young rapids the first value on urp asset under "shadows" is "max distance"

your perceived shadow resolution is basically just combination of the overall shadow map size in the map (distance from camera) and it's resolution

if we neglect the different shadow filtering algo's effect for a second here that is

but those wouldn't actually change the shadow resolution, just how it looks

[young rapids]

Ahh, thank you. Shadow's are appearing in game view but not editer though

[wispy tinsel]

how to make hands (or other parts) of model to collide with other objects properly?
Right now, during attack animations, hands just go inside of mesh.

[young rapids]

The issue with realistic gravity 😅

[timid dove]

You should generally use Inverse Kinematics to properly position hands during animation

[young rapids]

I've just realised, for some reason my objects now have 0 bounciness

Even when I set them to max

[young rapids]

I-

This is really going downhill

[distant linden]

No pun intended

[young rapids]

I mean, yeah XD

I've gone back to the old scale, everything x 100, and it's working much better.

Just used normal gravity x 4, which is technically less than half what it should be, but it's working pretty well.

[young rapids]

How do you use a non-convex collider?

[timid dove]

If it's a static object, there's nothing special to do

if it's a moving object, it's better to build up the collider out of multiple primitives if possible

[young rapids]

Ah ok

I've found a non-convex collider on the asset store too that I'm trying

Though, it seems to be voxel based...

[young rapids]

It seems a little funky, though may just be my mesh

[timid dove]

If the mesh geometry is abnormal it may certainly cause issues

[timid dove]

seems ok to me? 🤔

[young rapids]

Yeah, it works, just not as smooth as I hoped

Actaully I think I know why

There's a bug with the voxel collider I bought, it wouldn't go away even when the component was removed

[lapis plaza]

@young rapidsfor that type of collision, I'd use contact modifications (only available since Unity 2021.2) but it's bit more advanced concept

[young rapids]

Baring in mind I really starting learning unity 2 days ago XD

[lapis plaza]

yeah, hence mentioning it not being something I'd recommend for newcomers, it's not that well documented and you have to figure out the math yourself if you use it

(it basically lets you spoof collision pair data before physics engine solves the collisions based on the data)

[young rapids]

I think the collision's fairly satisfying at the moment. The only issue is my marble crushing something light like the small die against a wall is very bouncy

[lapis plaza]

also btw, there's a package from Unity that lets you do VHACD but it's not exactly easy to find

(basically similar thing that paid nonconvex thing from asset store does)

https://github.com/Unity-Technologies/VHACD/tree/main/com.unity.robotics.vhacd

right now this is only available via github so you can't use package manager to fetch that one

also worth noting that I haven't ever tried this specific package but I have used other VHACD wrappers for Unity in past

[young rapids]

Yeah this is the first asset I'm considering refunding

Cause, anything other thing the small props in the examples, voxel's are not gonna work

[lapis plaza]

refunding is tricky, especially if you've already downloaded the asset

unless the asset publisher is willing to give refund and the asset does what it's advertised, Unity doesn't typically give a refund

only exception is if you just bought the asset and haven't downloaded it yet

[young rapids]

Yeah, it's alright

There's no collider for a cylinder?

[lapis plaza]

no primitive type for it on physx no

you need convex collider for it

(or capsule with those contact modifications)

[wispy tinsel]

bruuuuuh, watched long video on IK and when time came for actual code part it said "buy full course here" and skipped it

feels like IK is some kind of black magic rn

[kindred lion]

WASD - move
Space - jump
Shift - dodge/airdodge
I - shorthop

thoughts? i made this in two days

[neon solstice]

I have been playing with physics. I attached camera to cube and trying to move it around

When I move this cube to one side of another cube, it phases through.

But when I move it to another side of cube, it collides properly

why does it happen?

A static object is like "pushing it out"

[young rapids]

I want to make some kind of swing for my marble platformer, using physics

Is it realistic for me to just make it so when the swing hits the middle point, it adds some force to keep it going, so it doesn't slow down?

[urban wolf]

I'm having a problem with physics being really unstable in a pooling situation.

Background: I'm building a large VR game for the Quest, with lots of interactable, simulated items. Think houses full of objects you can grab, push, open, pick up, including furniture elements. Now since most of the houses share stuff, I decided to pre-spawn all of their contents, and just move them between houses as the player changes position. The pooling works, but most of the simulated bodies exhibit really unstable behaviour.

Process: When the player gets in proximity of a building I populate it as follows:

1. Get all item positions from special markers present in the scene, and get the correct object instances from object pools.
2. Set all object rigidbodies to kinematic, move then to their designated positions (I use both transform.position and rigidbody.position), and set their GameObjects active.
3. Gradually remove the kinematic flag on all rigidbodies, 2 per frame, to avoid CPU spiking. Large objects (i.e. furniture elements) are handled first, small objects second.

Problem: Things explode during the last step. It's mostly items positioned inside furniture drawers that get haywire to the point of blowing the drawer open and flying out (or through). All of them are carefully positioned by simulating gravity inside edit mode, so there's no collider intersection. Nearly everything in the scene uses box colliders. My simulation steps are set to 12, and I don't really have the budget to set them higher, due to sheer amount of items in each house.

Is there any way to make this behave less volatile?

[young rapids]

I think I need to move here from beginners

My marble's kind of...gliding?

I'm just gonna post my entire playerController and hope someone can see an issue https://gdl.space/lulifosedu.cs

[wispy tinsel]

What is better for perfomance:
9 simple cube colliders or 1 mesh collider in form of box (that has empty space inside)?

[urban wolf]

cube colliders

that mesh collider would have to be concave, and those are the worst kind for performance

also that would prohibit your object from being a dynamic rigidbody

[wispy tinsel]

oh yeah, those are nice points

so best practice is creating buildings/environment out of multiple simple meshes instead of creating complex meshes?

[urban wolf]

that kinda depends on how exactly the meshes work

but for complex geometry, we usually separate colliders from the meshes

i.e. scene geometry that's immobile

and either make it all box colliders

[wispy tinsel]

yeah, I know about that feature

I guess my question is a bit out of perfomance question here

[urban wolf]

or prepare separate mesh colliders that are simpler than the item itself

[wispy tinsel]

but more of level design practice

[hardy ether]

you could make a low poly version of the mesh, add a mesh collider, and set it to convex

it's uses less performance, and it's still dynamic

technique I want to try but haven't got the time to recreate the physic meshes

[torpid nacelle]

i am looking for some explanation or code for how boxcollider2d and rigidbody2d work by default, i mean that the box that has force pushes another box if it is not stationary

i want to implement such behaviour outside unity

[timid dove]

unity uses Box2D for 2D physics

All the code is open source https://github.com/erincatto/box2d

You can just use Box2D in your non-unity application if you want

No need to reinvent the wheel

[torpid nacelle]

i found it more difficult to import and make box2d working than to make my own physics, but your tip is useful that unity uses box2d

[neon solstice]

I have attached the following script to my cube:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class ShipController : MonoBehaviour
{
    // forward movement speed
    public float forwardSpeed = 25f;
    // side to side movement speed
    public float strafeSpeed = 7.5f;
    // how fast we move up and down
    public float hoverSpeed = 5.0f;


    private float activeForwardSpeed;
    private float activeStrafeSpeed;
    private float activeHoverSpeed;
    // Start is called before the first frame update
    void Start()
    {
        
    }

    // Update is called once per frame
    void Update()
    {
        activeForwardSpeed = Input.GetAxisRaw("Vertical") * forwardSpeed;
        activeStrafeSpeed = Input.GetAxisRaw("Horizontal") * strafeSpeed;
        activeHoverSpeed = Input.GetAxisRaw("Hover") * hoverSpeed;
        
        Vector3 forward = transform.forward * activeForwardSpeed * Time.fixedDeltaTime;
        Vector3 strafe = transform.right * activeStrafeSpeed * Time.fixedDeltaTime;
        Vector3 hover = transform.up * activeHoverSpeed * Time.fixedDeltaTime;

        Vector3 movement = forward + strafe + hover;
        this.GetComponent<Rigidbody>().MovePosition(this.transform.position + movement);
    }
}

Cube moves, but... it does not collide with other cubes on scene

Here is a hierarchy

I have these settings on a moving cube:

These are settings on another object

How do I get collisions here?

[urban wolf]

you are getting collisions, but they are not resolved by physics simulation

kinematic rigidbodies can only be moved by script, physics simulation will not affect them, nor any other forces

i assume you want a rigidbody that is controlled by you, but also behaves correctly after hitting something

there are two ways to do that - either leave the RB kinematic and simulate your own collision response, or turn off kinematic and use forces to move it (rb.AddForce, rb.AddTorque)

which one is better depends on how your game is built

[neon solstice]

So, I assume that I should change line
this.GetComponent<Rigidbody>().MovePosition(this.transform.position + movement);

What is Kinematic for?

[daring furnace]

https://docs.unity3d.com/ScriptReference/Rigidbody-isKinematic.html

[neon solstice]

Thank you so much!

I disabled IsKinematic on my object

and used

this.GetComponent<Rigidbody>().AddForce(movement);

Now collisions are processed properly.

And it added up a bit of innertia, which looks cute

[urban wolf]

as a side note, caching components you perform frequent operations on is considered good practice, since fetching the component is rather expensive - this quickly adds up in larger projects

glad to hear a simulated rigibody worked out for your use case

[stuck bay]

Speaking about rigidbodies, I have add relative force to a rigid body with a 100 units of mass. when they colide the bounce off of each other like expected but, it's too much. The space ships spin out of control and move away for far to long.

What variables should I look into to solve this? Drag maybe?

angular drag?

Yes, it was angular drag. I guess I had to think that one up out loud

[wary dagger]

does omitting an object from collision for another specific object require a script?

[wary dagger]

all goods, sorted it out with the layer matrix

[rigid mica]

Why does a normal rigidbody not have a gravity scale unlike a 2D rigidbody?

I am trying to edit how fast a certain object falls

[unique cave]

Probably because its unrealistic to have different gravity scales and they didnt find it too useful to have that because its super simple to code the gravity yourself if youre not happy with the build-in gravity

[rigid mica]

But it would be realistic if the objects had different weights

[unique cave]

2d and 3d physics also uses different physics engines and unity have different teams working on them so not all the features are same

[unique cave]

No its not, in real life falling acceleration is same for every object no matter the weight

[rigid mica]

Okay I dont really know much about physics. I guess I just have to make my own system

[unique cave]

You can just disable the gravity and use addforce (use ForceMode.Acceleration) to add gravity

rb.AddForce(Physics.gravity * gravityScale, ForceMode.Acceleration) should work

[rigid mica]

Thanks

[runic harbor]

I got a ragdolled ( through wizard ) character, I need it to swing around a pole. The hands are connected to the pole with a Fixed Joint component.
I can't make it swing around the pole
https://gyazo.com/6164c634b6022adf2b3db5ed66a2c197
This is the code

        if (Input.GetMouseButton(1))
        {
            bone_spine.GetComponent<Rigidbody>().velocity = new Vector3(bone_spine.GetComponent<Rigidbody>().velocity.x + 0.1f, bone_spine.GetComponent<Rigidbody>().velocity.y + 0.1f, 0);
        }



        if (Input.GetMouseButton(0))
        {

            bone_spine.GetComponent<Rigidbody>().velocity = new Vector3(bone_spine.GetComponent<Rigidbody>().velocity.x - 0.1f, bone_spine.GetComponent<Rigidbody>().velocity.y - 0.1f, 0);
           
        } ```
I'm completely lost, do y'all have any resources about this kind of ragdoll physics?

and is what i'm trying to achieve even possible?

[pearl tendon]

Unity is weird at times. I'll never understand that when you a rigidbody. when the built in character controller. than attempt to move the character is unaffected by gravity until you stop moving

[pure quarry]

i just started out with unity, so this is a basic problem im guessing.
im trying to have a capsule being controlled by the player be able to move around and whatnot. The problem im having is that when the player tries to move into another rigidbody object, it looks like the capsule shudders back and forth until i stop moving toward the cube.
code for player:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class playerScript : MonoBehaviour
{
    public string testString = "this working?";
    public float lookSpeed = 3;
    public float moveSpeed = 3;
    private Vector2 rotation = Vector2.zero;
    private Rigidbody rb;

    void Start()
    {
        Debug.Log("player active, " + testString);
        Cursor.lockState = CursorLockMode.Locked;
        Cursor.visible = false;
        rb = GetComponent<Rigidbody>();
    }
    
    void OnCollisionEnter(Collision collision)
    {
        moveSpeed = 0;
    }
    
    void Update()
    {
        float horizontalInput = Input.GetAxis("Horizontal");
        float forwardInput = Input.GetAxis("Vertical");

        rotation.y += Input.GetAxis("Mouse X");
        rotation.x += -Input.GetAxis("Mouse Y");
        rotation.x = Mathf.Clamp(rotation.x, -15f, 15f);
        transform.eulerAngles = new Vector2(0,rotation.y) * lookSpeed;
        
        Camera.main.transform.localRotation = Quaternion.Euler(rotation.x * lookSpeed, 0, 0);
        //Move the object to XYZ coordinates defined as horizontalInput, 0, and verticalInput respectively.
        transform.Translate(new Vector3(horizontalInput, 0, forwardInput) * moveSpeed * Time.deltaTime);
        moveSpeed = 3;
        if (Input.GetKeyDown("escape"))
        {
            Cursor.lockState = CursorLockMode.None;
        }
    }
}

all im doing here is moving sideways against the cube, and it stutters and tilts the player

[urban wolf]

is the rigidbody on the player kinematic?

also, irrespective of that

you should be using a player controller component for stuff like that, it has built-in deflection on collisions, so you won't be forcing the player into the object you're collinding with

https://docs.unity3d.com/ScriptReference/CharacterController.html

[timid dove]

Rigidbody and CharacterController are two completely different approaches to character movement and should not be used together, as they will conflict.

[jovial wraith]

moving your object with Transform.Translate does not play nice with physics. You want to use Rigidbody.MovePosition or Rigidbody.AddForce or use a CharacterController. And do it in FixedUpdate, not Update.

[timid dove]

or setting the Rigidbody's velocity directly works too

[pure quarry]

yes

[urban wolf]

yeah, that's better than translating a simulated rigibody at least

you might want to a) move your code to FixedUpdate, since that syncs what you're doing with the physics simulation b) use rigidbody.MovePosition

but that still won't give you nice collision deflection

for a beginner i'd suggest using the character controller and removing the rigidbody

you'll get far nicer results

[timid dove]

If the body is kinematic I don't think it's going to respect any collisions at all

even with MovePosition

kinematic objects are unstoppable forces

[pure quarry]

so i fixed it, but now whenever i try and move while looking around with the mouse, it gets kinda buggy. should i change anything about the way it looks around?

[urban wolf]

yeah

[pure quarry]

ok so when i try doing both, it only lets me do one

[timid dove]

do rotation in Update

[pure quarry]

like i cant look and move at the same time

[urban wolf]

you should rotate the player controller on the y (up) axis, but rotate the camera parented to it on the x axis

[pure quarry]

yeah i am

[timid dove]

in what way exactly is it buggy, and how's the code look now

[pure quarry]

void FixedUpdate()
    {
        Vector3 m_Input = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
        rb.MovePosition(transform.position + m_Input * Time.deltaTime * speed);
    }

    void Update()
    {
        rotation.y += Input.GetAxis("Mouse X");
        rotation.x += -Input.GetAxis("Mouse Y");
        rotation.x = Mathf.Clamp(rotation.x, -15f, 15f);
        transform.eulerAngles = new Vector2(0,rotation.y) * lookSpeed;
        
        Camera.main.transform.localRotation = Quaternion.Euler(rotation.x * lookSpeed, 0, 0);
        
        if (Input.GetKeyDown("escape"))
        {
            Cursor.lockState = CursorLockMode.None;
        }
    }

[pure quarry]

when i move around and look around at the same time it stops the player movement until i stop looking around

like it wont process mouse and keyboard inputs at the same time

ok and also i just played around with it more, and let me figure out how to word how this is broken

moving forward/back/left/right is broken, like it doesnt register me turning to be a change for moving. so when i turn and look to the right, pressing w doesnt make me move forward, instead it moves me to the left. or if i press play, then look behind me, pressing s would move me forward, and w would move me back

[urban wolf]

that's because you're moving the character by an absolute direction, not his local "forward" direction

Vector3 m_Input = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical")).normalize;

first off, normalize your input

now let's try rotating this vector so it matches the direction your controller is facing

rb.MovePosition(transform.position + (rb.rotation * m_Input) * Time.deltaTime * speed);

might work, might not, but it'll get us somewhere

[pure quarry]

i put .normalize in that line and it gave me an error

Vector3' does not contain a definition for 'normalize' and no accessible extension method 'normalize' accepting a first argument of type 'Vector3' could be found (are you missing a using directive or an assembly reference?

[timid dove]

normalized

[urban wolf]

yeah, normalized

[pure quarry]

ok

still the same issue 🥲

[urban wolf]

hang on, let me try to do it on my end

well, it works on my end

        rb.MovePosition(transform.position + (rb.rotation * m_Input) * Time.deltaTime * speed);```

[vernal musk]

I am just trying to make a simple pong game using unity physics to control the bouncing of the ball, but after several bounces the ball always ends up going either straight up and down or side to side. does anyone know the issue?

I already set bounce to 1 for the physics material and changed the bounce threshold to 0 in the project settings

figured it out. all the objects materials need to have bounce set to 1

[pure quarry]

maybe its the code i use for mouse. heres my full script

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class playerScript : MonoBehaviour
{
    public float lookSpeed = 3;
    private Vector2 rotation = Vector2.zero;
    public float speed = 5f;
    Rigidbody rb;

    void Start()
    {
        Debug.Log("Start() works on player");
        Cursor.lockState = CursorLockMode.Locked;
        Cursor.visible = false;
        rb = GetComponent<Rigidbody>();
    }
    
    void OnCollisionEnter(Collision collision)
    {
        //moveSpeed = 0;
    }

    void FixedUpdate()
    {
        Vector3 m_Input = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical")).normalized;
        rb.MovePosition(transform.position + (rb.rotation * m_Input) * Time.deltaTime * speed);

    }

    void Update()
    {
        rotation.y += Input.GetAxis("Mouse X");
        rotation.x += -Input.GetAxis("Mouse Y");
        rotation.x = Mathf.Clamp(rotation.x, -15f, 15f);
        transform.eulerAngles = new Vector2(0,rotation.y) * lookSpeed;
        
        Camera.main.transform.localRotation = Quaternion.Euler(rotation.x * lookSpeed, 0, 0);

        if (Input.GetKeyDown("escape"))
        {
            Cursor.lockState = CursorLockMode.None;
        }
    }
}

[stuck bay]

hey how would i be able to move this green brick against the wall?

this is how the joint moves

The table has box colider only
The green box has Box colider, rigidbody(freez position on z, freeze rotation on x,y,z, and has continus detection) everything else is default
The end joint has Capsulie colisder, rigidbody(free rotation, position on all axis, no gravity)and evetythin is defualt

[urban wolf]

@pure quarry ok, i see the issue

here's the working controller with explaination

public class PlayerController : MonoBehaviour
{
    public float speed = 5.0f;
    public float lookSpeed = 400.0f;
    public Rigidbody rb;
    private Vector3 rotation;

    private Vector3 mouseInput;
    private Vector3 kbInput;

    void Awake()
    {
        rotation = rb.rotation.eulerAngles;
        Cursor.lockState = CursorLockMode.Locked;
    }
    
    // Turn on interpolation in the rigidbody component for smoother movement.
    void FixedUpdate()
    {
        var oldRot = rb.rotation;
        var newRot = Quaternion.Euler(0, oldRot.eulerAngles.y + (mouseInput.x * lookSpeed * Time.fixedDeltaTime), 0);
        rb.MoveRotation(newRot);
        rb.MovePosition(transform.position + (rb.rotation * kbInput) * Time.fixedDeltaTime * speed);
    }

    void Update()
    {
        mouseInput = new Vector3(Input.GetAxis("Mouse X"), Input.GetAxis("Mouse Y"));
        kbInput = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical")).normalized;

        rotation.x = Mathf.Clamp(rotation.x - (mouseInput.y * lookSpeed * Time.deltaTime), -35f, 35f);
        
        // transform.eulerAngles = new Vector2(0,rotation.y) * lookSpeed;
        // !!!
        // You can't manipulate the transform *and* move the rigidbody.
        // Doing this will cause objects to be forcibly re-synced, thus i.e. blocking movement when rotating.
        // If a rigidbody is present on a gameobject, you only move the rigidbody and leave the transform alone.
        // Rigidbodies exist independently in a "physics-world", and then sync transforms to their positions in game scene after a simulation step.
        
        // Instead we only rotate the camera (since it's not a rigidbody), and store the remaining inputs to be processed in FixedUpdate.

        Camera.main.transform.localRotation = Quaternion.Euler(rotation.x,0 ,0);
        
        if (Input.GetKeyDown("escape"))
        {
            Cursor.lockState = CursorLockMode.None;
        }
    }
}

[balmy void]

does anyone know how linear drag is calculated in unity? I can choose the values I need, but I would like to be able to control them precisely.

[urban wolf]

velocity = velocity * ( 1 - deltaTime * drag);

done inside physx

[balmy void]

The result is completely different values.

[urban wolf]

is this 3D physics or 2D physics?

[balmy void]

2d

[urban wolf]

then it's not physx

it's box2d

found this, not sure if it's current

https://gist.github.com/jrenner/5516658

you can verify that here

https://github.com/erincatto/box2d

[balmy void]

v *= 1 / (1 + deltaTime * linearDrag)

Found. If anyone needs it.

[young rapids]

This feels a lot slower than it should be...

[flat pewter]

How would I set up a series of joints to work similarly to the Dynamic Bone plugin? Specifically, imagine you cut down a sapling and stripped it down, how springy it would be as you waved it around. It would flex on both axes, but not stretch, and return to its original shape when you stop moving it. I thought about using a hinge joint, but that only rotates around one axis. I then tried using a character joint, setting the twist limits to 0, and setting the swing limits to 0 but giving them some bounciness, on the theory that if the swing were higher than 0 they would swing but not return to their original position, and the bounciness would be what allowed them to flex beyond the limits, but this doesn't seem to work at all.

I don't want to use Dynamic Bones because they require their own colliders and don't collide with the world, and I can't adjust the mass of things to get proper physical reactions.

[unique cave]

Its either gravity or drag (or your script) thats making it slow

[young rapids]

There's no drag, and gravity is 4 times stronger already.

I made it 10 times stronger and it was still slow like that

[unique cave]

Are you simulating rolling resistant yourself in code?

[young rapids]

No, it's mostly just the rigidbody. My movement code is just adding force./torque.

[unique cave]

Well, adding force and torque can very easily cause that 😄 . Have you tried disabling the movement script and testing if its still as slow even with high gravity?

[marble vale]

so for some reason the mesh collider doesn't work for me. I'm trying if one piece will fit into another, for 3d printing, in unity but it doesn't have a collider

[pure quarry]

thanks, but ah, how do i use the controller with the player? right now its saying that "the referenced script on this behavior (game object 'player') is missing"

[urban wolf]

paste it into a fresh script called PlayerController

[pure quarry]

should i change public class PlayerController : MonoBehaviour?

[urban wolf]

or rename to your class

[pure quarry]

ah ok thats what i was thinking

[urban wolf]

filename and class name have to match

[pure quarry]

that the name of it was not right

thanks

[stuck bay]

how do i move gameobject along x-axis with unity articulation body?

[flat pewter]

Is there something like Dynamic Bones which works with regular colliders? For one, I'd like them to collide with the world, and it's a real pain having to recreate all the colliders in the hands for dynamic bone colliders every time I update the Hurricane VR SDK. It's already got capsule colliders. I've tried using character joints to create a similar effect to Dynamic Bones but with no luck.

[young rapids]

I want to add a fan mechanic for my marble game.

I'm just wondering what the best way to do that is? Should I make a cylinder/capsole trigger in front of the fan, and make that add force to the player?

[runic harbor]

https://gyazo.com/e400590eca43f26b37a8c91cabd6f9f0

I'm trying to move around the ragdoll through one of its hands, however when I do this happens. How can i fix it?

[wispy tinsel]

Is there a way to kind of snap RigidBody to certain point (in my case it's where cursor is), while retaining all physics and collisions (so if that point goes behind wall, object will just get stuck behind it)?

[young rapids]

How would you make a see-saw in unity?

Like, an object that can move with a rigidbody, but is fixed in 1 point?

[neon solstice]

Hello. I am trying to apply a Torque to a rigidbody, but nothing happens.
this.GetComponent<Rigidbody>().AddTorque(torque);
torque vector is (0;25.0f; 0)

Am I missing something?

AddForce works fine

Oh

I had this enabled:

😂 🆗

[urban wolf]

@young rapids joints

[young rapids]

Does the other side need to be a rigidbody?

Or can it connect to something static?

[urban wolf]

if you don't specify a connected rigidbody on a joint instance, it's affixed to a point in space

[young rapids]

Thanks 🙂

It works, but is there a way to add..resistance to the joint?

Would that just be drag?

[vernal musk]

do you need a rigidbody for collisions to work?

[lofty coral]

I have made a knife script that damages an opponent when its close enough to the knife and the player presses "shoot" at the same time. Its just a raycast that damages the player if the raycast htis it. How would i make it so that the raycast is in a wider range? So it would go from a dot raycast to a line raycast if somebody understands.

[young rapids]

No, just a collider

[balmy void]

I have been sitting for a long time and I can’t come up with a solution

Let's say we have such values
F = 11
S = 10
DT = 0.02
V = 0.2 (initial value)
D =?

And there is such a formula.

V = V * (1 / (1 + DT * D))

It is necessary that through F repetitions V be as close as possible to S (9.8-10.2).

[pure quarry]

couldnt you shorten V = V * (1 / (1 + DT * D)) to V *= (1 / (1 + DT * D))?

[jovial wraith]

V *= (1 / (1 + DT * D)) repeated F times is the same as V *= Mathf.Pow((1 / 1 + DT * D)), F). Set that equal to S and solve for D.

[neon solstice]

I am curious, what is this equation for?

[sage wolf]

I am very confused, is NVidia FleX still a thing in Unity or is it not anymore ?

[supple sparrow]

You could cast a flat box instead of a ray for example

[supple sparrow]

Refer to the tables at the end of this page from the manual https://docs.unity3d.com/Manual/CollidersOverview.html

[urban wolf]

@lofty coral I believe Physics.BoxCast is what you're looking for

three raycasts (two for edges, one for knife's point) might be just as viable, though

also cheaper

[hushed lichen]

Hey, I'm trying to make a chain that swings back and forth and never slows down. I'm using hinge joints. Is there a way to do this?

[zinc hatch]

youtube

[hushed lichen]

Nothing

[wind quail]

i have been trying to figure this out for the past few days so don't judge me - my projectile (the white cube inside is for reference cause its hard to see without it) goes on a weird rotation if i spawn it while the camera is moving

  void Update(){
        if(Input.GetButtonDown("Fire1")){
            Shoot();
        }
    }

    // Update is called once per frame
    public void Shoot()
    {
        if(canShoot){
            GameObject spell = Instantiate(spellObj, transform.position, cam.rotation);
            spell.GetComponent<Rigidbody>().AddForce(spell.transform.forward * shootForce * 100f);
            canShoot = false;
            Invoke(nameof(ResetShooting), shootCooldown);
        }
        
    }

    public void ResetShooting(){
        canShoot = true;
    }

it shoots fine when the camera is still

[balmy void]

Hello, I'm currently making a smooth movement implementation for a platformer and would like to ask for help with a problem and advice from those who understand. I made vertical movement, like jumping, using addForce. I noticed that if there is an equivalent difference between mass and drag (1, 1 or 0.1, 10), then the acceleration will occur exactly to the specified value and I think I understand how it works, but now it doesn't matter to me. Thanks to this method, I can control acceleration, top speed and deceleration. While doing the jumps, I decided to use ForceMode2d.Impuls. Basically everything works the way I want it to except that my dragging slows down my jumping a lot. I tried to calculate and change the speed changes but it doesn't work. I would like to know your opinion on how this problem can be solved and whether it is worth using such an implementation at all.

[stiff topaz]

Hi, I'm making a 2D platformer, and I have an irregular shape roof, and I'm wondering if it's possible to make that roof (Which I use a polygon collider 2d) a one way collision? Meaning I can jump on it from below?

This is the roof shape

I know with a normal flat platform you can do a y check

[daring furnace]

It's possible. There are tutorials for that out there. I forgot what the term is though

[bleak umbra]

generally you can do that easily with a kinematic character controller that just ignores collider hits with a down-facing normal while moving up, but also with a physics driven one you can use a raycast to detect an upcoming collision with its normal and disable the edge when moving "up".

[stiff topaz]

I just found an extremely easy way to do that for anyone wanting to make one way platforms even at angles

There's a component called Platform Effector 2D

you can set how much of a platform is detected by collisions

[stiff topaz]

Does anyone know how to edit the collisionMask attribute in script? I'm trying to change a platforms collision with the Player layer when I press a key

[timid dove]

https://docs.unity3d.com/ScriptReference/Effector2D-colliderMask.html

[stiff topaz]

That doesnt show the syntax of how to change the values

[timid dove]

With the = operator, same way you change any variable/value

[daring furnace]

it's an int. You change it just like any other int

[unique cave]

Yesnt. You could change it as any other int but its bitmask, not regular integer representing the layer. You can make LayerMask variable with [SerializeField] attribute so you can change it on inspector. Then you can just set the mask to be that LayerMask variable. LayerMask is basically an int but it allows you to edit the mask without touching any bitwise operators and stuff

[late path]

does anyone know why my game object is bouncing when my player goes fast, btw im using velocity to change the the movement and my player is using rigidbody

[desert wave]

Are you using collision detection mode continuos?

And what about the physics material?

[late path]

oh about that i use no friction for my material

[desert wave]

And bpunciness?

[late path]

one sec

[late path]

sorry i gtg for a few mins ill be back

[desert wave]

Np

[late path]

alr im back and bounciness is at 0

[proven cipher]

lol

[desert wave]

Most probably is your movement

[late path]

want my script???

[late path]

i can send in #archived-code-general

[past notch]

i have an issue, sometimes ennemies and players fall though platform while walking on the ground when it looks like this

not code related since disabling the platform script still creates the issue

ok widening the surface arc seems to fix it

[graceful grove]

Hello,
this happens to me when I use rb.MoveRotation
is there any chance of keeping the player on that moving wing?
https://ctrlv.tv/0D5S

[molten snow]

Hello guys, I've got a physics/velocity problem. So my Character Controller should jump once after having a connection to a collider to the environment (here ground) and sometimes the Character just jump 10x -100x as high as he should and I don't understand why. Here is the extract of my code which controls it:

    public float jumpHeight; (assigned in Editor)
    private bool readyToJump;
    public Transform ground;
    public LayerMask groundLayer;
    public float groundDistance = 0.5f;

... update ()
... Jump ()...

void Jump()
    {
        readyToJump = Physics.OverlapSphere(ground.position, groundDistance, groundLayer).Length > 0;

        if (Input.GetButtonDown("Jump") && readyToJump)
        {
            velocity.y = Mathf.Sqrt(jumpHeight * -2f * Physics.gravity.y) * Time.deltaTime;
        }
        myController.Move(velocity);
    }

The gravity is constantly pushing the player down and resets the velocity if he is grounded, so I dont think there should be a problem with the speed

[molten snow]

(In another method) - Please feel free to @ me if you can help me with this

[timid dove]

You should not be incorporating deltaTime into a velocity variable

deltaTime Is reasonable for calculating a new position given a velocity vector, or the amount of velocity to add for an acceleration. But velocity itself should not be different because of a different framerate.

[flat jackal]

I'm trying to simulate an object at the end of a rope, as shown by the following video. However, I'm encountering an issue where the bounce doesn't damped, shown at the end of the video, and I'm not sure sure how to fix that. I'm not spectacular at physics, so I could already have the base calculations wrong. I'm also pretty new to Unity so that also doesn't help all that much

I calculate the amount to accelerate the cube by:

Vector2 distance = endPos - (Vector2)boxCollider2D.bounds.center;
float ropeLength = ropeSegmentLength * totalSegments; // Length of rope

if (distance.magnitude > ropeLength) {
    float mass = rigidBody.mass;
    float tension = 65f * (distance.magnitude - ropeLength) + 49f;
    rigidBody.velocity += tension / mass * distance.normalized * Time.fixedDeltaTime;
}

This is called from fixedUpdate()

[rugged rose]

added cloth component to this object and getting z flickering... anyone know how to solve this?

[lyric heath]

I'm working on a kinematic rigidbody character controller for a 3d game and I have this code which I call on every fixed update

private Vector3 ResolveCollisions() {
        Vector3 resolveCollisionsOffset = Vector3.zero;
        Collider[] cols = new Collider[16];
        
        LayerMask myLayerMask = GameUtils.MaskForLayer(gameObject.layer);
        int cFound = Physics.OverlapBoxNonAlloc(m_Col.bounds.center, m_Col.bounds.extents, cols, Quaternion.identity, myLayerMask);
        for (int i = 0; i < cFound; i++) {
            var c = cols[i];
            if (Physics.GetIgnoreCollision(m_Col, c) || m_Col.Equals(c)) {
                continue;
            }
            if (Physics.ComputePenetration(m_Col, transform.position, transform.rotation, c,
                c.transform.position, c.transform.rotation, out Vector3 dir, out float dist)) {
                resolveCollisionsOffset += dir * dist;
            }
        }

        return resolveCollisionsOffset;
    }```

This gives me the offset to get my character out of any walls or floors it may find itself in (so far). Anyone know how I can expand this to find collision points/normals without relying on OnCollision___() callbacks to provide collision data?

I think the data might already be in there. I'm just not really sure how the contact point is calculated, or how what I have could be used to find it.

[slate lily]

so short cut my player slides when it's grounded and its collider collides with the ground obj so tried to use the trace hit distance and added to the origin up the amount I go sink into the ground it works but when my player on hight speed it doesn't work for seconds untill he's on low speed again I do set the velocity to 0 when he's grounded kinematic rb

[young gulch]

not sure if this is the correct channel, but I have a few bugs with my code that will cause major glitches.
The first bug is when holding A + S + W + shift(sprint) the player sprints at higher than normal speeds.
First bug fixed
The second bug is when sprinting + jumping towards an object that is lower than the head camera, the player jumps at a higher distance than normal.

Looking for some help on how to solve these bugs.

[unique cave]

What is the reason for the flickering? Why is there overlapping geometry?

[rugged rose]

It’s a store asset. I think I’ll need to edit the geometry

[midnight basalt]

I need some help. I've got this continuous physics simulation where a ball spawns and follows a track. The issue is the path the ball takes is deviating between each ball (which shouldn't be the case as they're spawning in the same place each time). I can't quite seem to work out why it's not working properly.

[timid dove]

I don't think PhysX makes any promises about determinism or consistency. It's optimized for performance

[midnight basalt]

Yeah this is what I’ve been reading when googling this issue

So how can I get around it?

[lapis plaza]

there is "enhanced determinism" flag in physics setting but I don't think it would help on your use case

basically you can make that scene deterministic in way it always simulates the same way when you run it (meaning you get same behavior each time you start the scene again, but not for individual ball runs)

[midnight basalt]

Hmmm

I’m tempted to forget about the continuous simulation and get the scene to reset when the ball hits a trigger tbh

[lapis plaza]

why is the determinism important here?

[midnight basalt]

I just read about something called DOTS

[lapis plaza]

just curious why you care about it

[midnight basalt]

Basically, I wanted the ball to run it’s course then a new ball would spawn and would run the course again. Like a repeating animation loop

[lapis plaza]

well.. if you reload the scene, it should simulate exactly same way on next run

unless you actually alter the scene at the beginning yourself

if you have like checkpoints and stuff, you lose determinism there already since you can't restore mid simulation states 100% on physx

that DOTS "unity physics" package is stateless, so you that would help you there

on physx, bullet, havok etc you are dealing with cached states etc in addition

[midnight basalt]

For this particular situation I think a hard reset would work fine. Not an ideal solution but saves a lot of unnecessary headache

Kind of a shame in terms of the aesthetics though

[lapis plaza]

I haven't actually tested Unity's physx determinism, they could still mess it up somewhere... I did fix bunch of things a long time ago on Unreal to make physx fully deterministic there on each scene reload and it never deviated there

determinism is funny in a way that even single floating point digit change, no matter how small, can make physics objects bounce in totally different directions

[midnight basalt]

I was wanting to have the ball go off screen, destroy then drop in from the top

[midnight basalt]

Yeah I was reading a little bit about floating point accuracy

Deviation by a tiny margin (like .0000001) can knock the whole simulation off

[lapis plaza]

the reasons why checkpoints are pain for determinism:

• most physics engines have cached states which you can't manually restore
• physx rigidbody setters and getters do extra math operations which basically guarantee that due to floating point math accuracy, you can never tell if it's set the value exactly same as it was internally

on top of that, Unity could also do some operations in addition but we wouldn't know since we don't have source code access to this

for the dots physics, this is different, there we have access to everything

[midnight basalt]

I guess the only way to guarantee the ball takes the same path each time would be to do it with animation

[lapis plaza]

if it's not player driven thing, could just simulate it once yourself and record it's run into animation clip

there's https://docs.unity3d.com/Packages/com.unity.recorder@2.0/manual/index.html but I've never used it so can't tell much about it

[midnight basalt]

Interesting 🤔 thanks I’ll check it out

[flat jackal]

Anyone able to help me with this?

[young gulch]

When coming to a stop from walking backwards there's this slight push back before coming to a complete stop, and when you hold shift(Sprint) + S and let go of shift the push back is far noticeable

[unique cave]

Thats most likely the axis of GetAxis having too low gravity value

Gravity means the deacceleration towards 0 when releasing

You can change that from input manager

[young gulch]

Thank you! That was the issue. Messed around with the gravity values and found the perfect values and now the issue is fixed.

[quartz lichen]

How do I make it so Object3 swings with Object2 when it moves with Object1? It seems very hard to describe this.

Object3 will have a rigidbody. It is.. somehow "tied" to object2 so when object2 moves (Without a rigidbody force, (transform)), Object3 moves with it. But.. swings?

[desert wave]

Maybe with joints

[quartz lichen]

I thought so. What joints would I use?

Object2 does not have a rigidbody.

[desert wave]

Why don’t give it one

[quartz lichen]

Well, it is attached to an object that has a rigidbody as a child. I could add one though.

I want to be able to move it around without using force. (Since I would be moving it around with the Object1

[desert wave]

So like

The object 3 has a rope connected to object 2
And then object 2 is child to 1

[quartz lichen]

Yes!

[desert wave]

Yea use a spring joint (recommend looking at them)

Connect 2 and 3
And just child 2

[ashen gale]

can anyone help me? im trying to make a bmx game but the front wheel is on the ground and the wheel collider is up in the air but if i move the wheel collider it moves the whee

[quartz lichen]

Hmm I tried a spring but it was.. bouncy. I want it to be more of a hinge There is a hinge joint but I can't figure it out.

Object3 just doesn't move when Object1 is moved

[desert wave]

I gtg to sleep pretty late for me
I wish you the best of luck

[quartz lichen]

Thank you! You have helped a lot.

[gloomy hornet]

hello :)
I am using a rigidbody character controller/mover I put together but it moves the character by setting velocity,
this does not fit with my intentions because it overwrites any external forces being applied to whatever character is using it.
I have tried using AddForce but each character has a different weight and just increasing the force applied by the character causes them to travel at different speeds when performing different movements, with some movements are entirely counteracted by friction...

Any suggestion on ways of keeping external forces and close to constant speed are appreciated.

[primal pivot]

Yes, use one of the ForceModes that ignores mass.

https://docs.unity3d.com/ScriptReference/ForceMode.html

You will need to use Acceleration or VelocityChange modes

[young gulch]

hi. What's causing my player to jump higher than normal when sprinting + jumping towards objects like these?

[desert wave]

is your gravity being applied while the jump happens meaning that it might deactivate when you touched the boxes

or it could be that your velocity vector has some value on the y

cause it bounces

[timid dove]

Likely your code is not properly handling the relevant vector math

[silver swan]

Hello!
I have two vectors, first of which is velocity of a rigidbody and second is transform.forward of an object (just a point defining that forward direction).
How can I make so velocity becomes 0 in all directions except for that transform.forward direction?
If I just do Vector3.Scale(rb.velocity, point.forward.normalized); it will work fine with those points which direction isn't angled to a world axis, but if it's angled, velocity won't be properly stopped in other directions than that forward.
Example of how it looks in a game is in this video, where at the second clip player's velocity isn't stopped how it's needed and it leads to falling.
This is happened because point.transform.forward is something like (0.7, 0, 0.7) and when scaling it with velocity it's probably really problematic.
What I want to do is to make player stop on the moment it begins the rail grind, but I want to keep it's momentum in direction of this rail, so it doesn't stop and accelerate from 0 every time it begins grinding.

[silver swan]

finally came up with a good working solution, where I just used the overall magnitude of velocity

[timid dove]

Vector projection is what you're looking for. Vector3.Project

[silver swan]

oh yeah you're absolutely right! should've looked up vector3 functions, didn't know there's one for this...

[proven patrol]

Damn this game looks so sick 🔥🔥

[silver swan]

I was testing out which way works better and well.. it's complicated a bit
Using my way, when hitting an angled rail, almost perpendicularly it bounces off? While it can look damn awesome as a game feature, it's still uncontrollable and only happens on angled rails
And trying this exact thing but with Vector3.Project, it just slips off the rail.
Note that it only happens if player is angled in a range of 70-120 degrees from the rail that is also angled relatively to world axis
But why?

[flat pewter]

Are there any tools / scripts out there for automatically adding joints and colliders to a chain of bones like an ear or a tail which will make it behave like the dynamic bones plugin, with springiness? If I use the Dynamic Bones plugin I have to create specific colliders for the bones on my VR hands, I have to assign those colliders to every avatar with dynamic bones, and those dynamic bones wouldn't be able to collide with the environment. It seems absurd to do this when Unity already has all the physics stuff built in. And if I don't have to create the scripts myself to set all this up, well, that'd be nice. Plus I'm not exactly sure what settings to use for those joints, so it would save me a lot of trial and error.

[graceful grove]

https://ctrlv.tv/mNo5
Does anyone know how to do that when standing on the propeller so that the player does not turn so unnaturally? The parent's throw didn't help .

[rough lodge]

My colliders are phasing through each other (both in 2D and 3D), even when there are rigidbodies attached

[hollow echo]

Are they just moving via gravity and forces?

[rough lodge]

in 3d, the movement is through script

well, in general it's through script

though I think it's 2 different issues. In 3D the collision is detected but it still phases, while in 2D the collision isn't even detected

[hollow echo]

If you're moving them via their Transform instead of via the Rigidbody's force/velocity/MovePosition you're bypassing the physics simulation

[rough lodge]

ah, so that's why

IDK how I could make it work though (this is for the controllable character)

@hollow echo though wait, I'm using "Physics.SyncTransforms();"

[hollow echo]

That doesn't help, that will just teleport the physics system to where the transforms are

[rough lodge]

oh, in that case what should I do

[hollow echo]

Use forces/velocity/MovePosition

The functions on the Rigidbody that are not just .position

[rough lodge]

oh, so I move the object through the rigidbody instead of its own transform

[hollow echo]

The physics system can only react to collisions if it understands how the object moved. If it's being forced to a position then it can only resolve penetrations, and if it's being forced there every frame it might resolve and then be overridden by that movement.

[rough lodge]

ah, wait in that case what's the character controller for?

wait, wait, wait. @hollow echo I just noticed something, I wasn't using transform.position to move, I was using the character controller's .Simplemove

[hollow echo]

I'm not very familiar with character controllers, but I thought that was physics-based

The other reason physics objects would not collide (that isn't code moving them improperly) is if their layer based collision is set up to not collide.
https://docs.unity3d.com/Manual/LayerBasedCollision.html

[rough lodge]

thing is, they are colliding (like, oncollisionenter works)

but they're passing through each other

[hollow echo]

Are they travelling at high speeds?

[rough lodge]

nope

really slowly

[hollow echo]

they're somewhat real-world scaled objects? In the realm of meters not milimeters or kilometers

If they are, that should work. Recording a video of what happens would be helpful

[rough lodge]

ok, give me a moment

but first, here's the rigidbody info on the player

[hollow echo]

If the player is using a character controller it shouldn't have a rigidbody on it afaik

[rough lodge]

I only added the rigidbody today though, before that it was already passing through things

though I think the other object didn't have one before that?

ok here it is

(I already took out the rigidbody from the player)

[hollow echo]

If things don't move, they don't need rigidbodies.
And character controller uses this callback when it hits things https://docs.unity3d.com/ScriptReference/CharacterController.OnControllerColliderHit.html as it doesn't use Rigidbody

[rough lodge]

taking out the rigidbodies changes nothing

[hollow echo]

why is that box in the floor?

how is it staying in the floor?

[rough lodge]

the floor is a plane using a meshcollider, so that may change things? IDK

it doesn't have a rigidbody btw

[hollow echo]

yeah but how is that box just stuck there and not falling through it or being pushed around? It shouldn't be able to be half in the floor

Is its rigidbody position constrained there or something?

Or is it marked as static?

[rough lodge]

oh I thought you meant the moving one. It's not static but yeah its position was constrained. Though without the rigidbody nothing changes

[hollow echo]

It's marked as IsTrigger

triggers are not solid

[rough lodge]

yes

oooooooh

ok

🤦‍♂️

though now I still have my issue with the 2D collision just straight up not working

[hollow echo]

It's gotta be one of the issues I've mentioned previously. Screenshotting what's involved / posting videos will definitely help if you cannot track it down

[rough lodge]

this one is through transform.position, but wouldn't the oncollisionenter function still be called?

[hollow echo]

If it worked, it would work inconsistently at best

[rough lodge]

here's a video either way

[jovial wraith]

sorry, I didn't read all the context, but its a big red flag that both Rigidbody2Ds you showed in that video have static body types. You should read about the different body types: https://docs.unity3d.com/Manual/class-Rigidbody2D.html

A Static Rigidbody 2D is designed to not move under simulation at all; if anything collides with it, a Static Rigidbody 2D behaves like an immovable object (as though it has infinite mass). It is also the least resource-intensive body type to use. A Static body only collides with Dynamic Rigidbody 2Ds. Having two Static Rigidbody 2Ds collide is not supported, since they are not designed to move.

[clever vigil]

Hi, I have a rigidbody (player) I push around a terrain. Problem is that most of the times the rigidbody will clip trough the terrain (shown in video). I have tried all the different Collosion detection on the rigidbody with no luck. Does the roughness of the terrain play any role in this? Also after the application has run for a while I see a huge increase in the physics processing in the profiler

[timid dove]

how are you moving the body? If you're not moving it in a physics-friendly way, collisions will generally not be respected

[clever vigil]

Using rigidbody.MovePosition

[timid dove]

hmm - do you need it to be a Rigidbody really? You might have better luck with a CharacterController

Is it going to be pushing other objects around?

[clever vigil]

I am using a rigidbody because i am mobning it around based on GPS coordinates, but guess I can still do that with CharacterController?

[timid dove]

yeah CC works pretty much the same way as a RB with MovePosition

main difference is it won't push around other rigidbodies

Also the limitation of only being capsule shaped

[wind quail]

i have been trying to figure out this for ages so don't make fun of me if it is something really simple -
my instantiated objects is normal when my player is still (and the place where the position parameter is referenced from is a child of the player) but when the player moves it acts really weirdly

[timid dove]

Looks like they're children of some object which is not scaled uniformly

That will cause skew especially as they're offset from the parent

[wind quail]

i just restarted unity and it now works...!?

[young gulch]

Hi. There's a pushback when crouch and crawling sideways and backwards when the value is set to low. I had this issue before when my height was set to normal and all I had to do was adjust the gravity of the axis but that doesn't work for this.

[runic surge]

I have a question for the Photon Quantum / TrueSync developer's

With TrueSync, your Rollback solution will only restore a world that has the corresponding body's already existing. If a Body was removed on frame x and a rollback was required on frame x + 1, the rollback would fail.

Is this because it would be to difficult to instantiate the game object for the physics body you are rollback?

Just curious 😛

[timid dove]

Photon/Exit Games has their own discord and the devs are pretty active there. You probably won't get an answer here but will probably get one there

[runic surge]

Thank you!

[desert wave]

did you solve it?

[young gulch]

no

just been working on other stuff

[grizzled mango]

Hi ihave a problem with this paper bin. i don't know how i can make the collider.

[unique cave]

have you tried mesh collider?

[grizzled mango]

Yes but it don't creates the hole

[unique cave]

you have to uncheck the convex toggle

also that seems quite high high poly mesh so id definitely make a low poly version of that and use that for the mesh collider so it renders the high quality mesh but physics uses the low poly one

[grizzled mango]

thanks i'll try it.

[young gulch]

anyone?

[fluid mirage]

I'm trying to make a windsock. I already modelled one, but now I want it to do something. I made a wind volume that adds fluctuating forces to rigisbodies within it. Now I would like to make a windsock to show the direction and strength of the wind in knots.

I tried using cloth, but it doesn't respond to forces unless I specifically set them (not a huge deal, just not ideal). On top of that I can't get the cloth to behave the way a windsock does. Also it collides with itself because of the shape.... Altogether it just seems like a difficult component to use for this.

Any tips? Tricks? Suggestions? How would you make a windsock that responds to forces?

I've also considered using an armiture and simply animating it manually, but that's really a last resort type of thing for me.

[mossy vine]

m_RigidBody.velocity = new Vector3(m_RigidBody.velocity.x / drag?, m_RigidBody.velocity.y, m_RigidBody.velocity.z / drag?);
What would be the appropriate way to calculate drag on this vector?

[timid dove]

That's up to you

There are many ways to compute drag

some more realistic than others

[mossy vine]

basically I want to set m_RigidBody.drag = 5f; but only for x and z

@timid dove so if I could use the internal method for drag on those directions that would be ideal.

[timid dove]

You can't

the internal method for drag is just a linear drag applied on all axes

[mossy vine]

Right

[timid dove]

http://answers.unity.com/answers/1108038/view.html

YOu can adapt this to only apply on the axes you want

[mossy vine]

m_RigidBody.velocity = new Vector3(m_RigidBody.velocity.x * (1f - Time.deltaTime * 5f), m_RigidBody.velocity.y, m_RigidBody.velocity.z * (1f - Time.deltaTime * 5f));
This appears to work! (for now)

@timid dove thanks for the help!

[fluid mirage]

I've just tried using multiple sphere colliders inside of the sock but that also doesn't work since the rotation causes the sock to slide off and move through the colliders making a mess.

On a sidenote, is this the right channel to ask this question?

[young gulch]

hello

[hallow egret]

What is the right way to move a rigidbody in tandem with a moving platform ? i could go just use the parenting method but is there any other way to do this ? preferably something that follow the physic of real world ?

i been looking into using dynamic friction but i don't know how to use it

[wraith junco]

@hallow egretWhat's wrong with parenting though? How does it not follow physics?

generally parenting is the way to get stuff to move with platforms

I've never done moving platforms with rigidbodies though so maybe I'm missing something

[hallow egret]

I got some weird issues when parenting, like scaling issues and weird jitter. But honestly im fine with just parenting, i could find a workaround it. I'm just looking if there's a better way of doing this

[wraith junco]

@hallow egretMaybe experiment with physics materials

or turn your guy into a character controller instead of a rigidbody when he's on a moving platform

I think if your moving platform isn't a rigidbody, you shouldn't really have many issues parenting a rigidbody player to it

[hallow egret]

im using a kinematic rb for the platform so the player could still collide with it. Is this wrong ?

[wraith junco]

rb can collide with any collider

by default

[hallow egret]

does that mean that it moves the rb too ?

like upward or if it just pushing it

[wraith junco]

kinematic means it doesnt talk to the physics engine (for the most part)

people use kinematic to return collision events

[prime trail]

So basically I have issues with player. It is not correctly colliding with other obstacles. What might be the problem?

[wraith junco]

both player and obstacle needs colliders

[prime trail]

Yes, both of them have colliders. But when I move a player to the obstacle, there is always a ~0.015 gap between them. Their colliders are squares with side length of 1

[wraith junco]

Is that really an issue?

You can probably play around with the collision detection settings on your rigidbodies

@prime trail You can also try playing around with this. Depenetration velocity sounds interesting

other than that, physx is pretty much a blackbox

mind screenshotting the gap between colliders?

[prime trail]

This is zoomed game. The white thing is a player, the brown thing is an obstacle. There is a gap between them. Also, player's position is -2.481784, 0.4850001 while I think it should be -2.5, 0.5

[wraith junco]

You'll need to show the actual colliders too

[prime trail]

The colliders are perfectly aligned in the scene editor, the thing happens only when I launch the game.

[wraith junco]

no clue

[unique cave]

that's using 2d physics ig?

physics are not very accurate anyways and it's very common to have little gaps here and there.

[fickle bluff]

hey all
I need some help

Beginner to unity here

I've trying to make a project
It's a snowboarding type game
Thing is, my main/board object is not falling correctly

It's like it will reach a certain height then fall straight

---

Any pointers on this ?

[desert wave]

well we need your code, tho probably a time.deltatime wasn't applied

[fickle bluff]

I don't think code will help here much

Because I've not written any code when Object is not in touch with ground

I think it has to with --rigidBody on Surface effector

but whatever you need,

We can probably join a VC , there I can everything required

[neat coral]

Check the air drag on the object

A higher value will result in a trajectory like you have shown

[fickle bluff]

thanks man you're epic
I tried some tweaks here and there with drag
And it worked !!

[neat coral]

[bitter pelican]

Does anybody know how to make the FPS controller a cylinder, not a capsule?

[unique cave]

Sadly cylinder collider doesn't exist in PhysX. you could probably try convex mesh collider with cylinder mesh on it.

if you want to make "perfect" cylinder shape with decent performance, you probably have to do contact modification. I'm not familiar with contact modification tho, maybe someone other can help with it if you want to give it a try

[bitter pelican]

oh

[mint warren]

hey, I think this is the place to ask - I just updated from unity 2019 to 2020 (LTS), and walls aren't working for me anymore. They just slowly push me out

(there's an invisible cube with a box collider over the particles)

previously collision worked perfectly, except for an occasional bug where an object slipped through, but yeah now it's like the walls are made of jello or something

[mint warren]

ok, I've figured out a jank fix, which is setting velocity instead of using MovePosition

[runic surge]

is DOTS physics really stateless

Hence I can serialize and deserialize just with bodies positions velocities masses etc?

[sonic lily]

So I made a ramp in blender.. converted it to a mesh.. exported as FBX I think it is.. and added a rigid body to a sphere.. but the sphere is falling through the imported mesh and landing on the plane(which was created in unity) below it

Ah nice found it. It was lacking the mesh collider

[obtuse fjord]

yo guys is there an alternative for rb.gravityScale for RigidBody 3D?

[sudden imp]

Guys is it possible to collide kinematic rigidbodies with other colliders like a normal physics with non kinamatics ?

I wrote a rewind system for time but when some other walls in map generated by code and also they are not rewindable so when i was rewinding the last (position,rotation,vel,angularVel) of rigidbody that doesnt collide with anything i cant figure out how can i do that with rigidbody ?

should i use extra physic scene or something like that ?

[timid dove]

You can only completely enable or disable gravity for a particular body. If you want something in between you have to implement it yourself

void FixedUpdate () {
  rb.AddForce(customGravity, ForceMode.Acceleration);
}```

[wispy tinsel]

What is difference of two Vector3?
x-y=?

for example if applied on positions

[timid dove]

It's the vector that gets you from y to x

Aka the difference

[wispy tinsel]

Is there some kind of article or table on that stuff?

I wonder what it means for velocities of objects then

[timid dove]

Think about it.
x-y gives you z such that
y + z = x

[wispy tinsel]

if you substract one velocity from another

[timid dove]

It's the acceleration(change in velocity) needed to get from one velocity to the other

[wispy tinsel]

delta velocity

I see

any tip how to google all that stuff?

I remember I learnt it like 5 years ago xD

I really need to refresh my head

[timid dove]

Subtraction always gives you the change you need to get back to the first from the second

No matter what the quantity represents

[wispy tinsel]

it's not just substraction I interested in

multiplication, division (if that's a thing)

adding

[timid dove]

There's at least 4 different ways to "multiply" with vectors and none of them are directly analogous to normal linear multiplication

[wispy tinsel]

not interested in actual math, but usage of it instead

[timid dove]

Addition and subtraction are pretty straightforward

Look up dot product, cross product

[wispy tinsel]

what about angular velocity of some object? Let's say cylinder.
What is the beginning point of that velocity vector?

I'm guessing it defines how object will change it's rotation only

[timid dove]

Yes it's the rate of rotation on each axis in degrees per second

[wispy tinsel]

you mean it's Euler angles?

x y z of angular velocity?

[timid dove]

Yes

[lusty arrow]

Evening guys,

I'm Working on an ALT+F4 type of game (platformer with traps) and I cannot find how to manage physics.

I got a really big rotating hammer above a platform, the idea would be to eject the player (rigid body with collider, mass 1, no drag, collision set to continuous) at the speed of the tip of the hammer (a box collider with kinematic rigidbody, collision set to continuous dynamic)...

But somehow the player is not yeeted properly, but squeeze is way through the hammer and is barely pushed...

The hammer is not even very fast: 1 second to fully rotate.

What do I miss.

[lusty arrow]

This is the setup.

[pure quarry]

human fall flat???

[lusty arrow]

But way shittier.

[obtuse fjord]

Alright understood, thanks for ur suggestion!

[stuck bay]

Hey im new here and to unity, im trying to add some interactions and Id love some help cause google doesnt have the guide ;-;

[wide nebula]

There's no such thing as the guide. Specify what you're trying to do.

[lusty arrow]

If you wonder why ⬇️

[stuck bay]

Hello, I have 2 meshes, each with a mesh collider (Convex turned off), next to each other.
They match perfectly (see screenshot). There is no gap/overlap.
When I roll a sphere over the "seam"/the cut where the meshes meet the ball jumps into the air as if it would roll over a bump. Does anyone know why?

[wispy tinsel]

How is center of mass defined in object?
Is it simply offsetting point from pivot?

[timid dove]

It's calculated from all the colliders on the Rigidbody. It's assumed the object is of uniform density. You can forgo the calculated COM and set your own on the Rigidbody however you wish if desired

[wispy tinsel]

I actually trying to understand difference between angular damping and inertia tensor

it seems pretty similiar to me

[timid dove]

So you know how objects with larger mass require stronger forces to get them going and have more inertia once they're moving?

Inertia tensor is the same thing but for rotation instead of linear motion.

And it is a Vector3 because an object can have "rotational inertia" that is different per axis

[wispy tinsel]

but I mean angular damping

not linear damping

[timid dove]

For example a sphere has the same inertia on all axes, but a long rod will spin much easier if used as an axle vs if it's tumbling lengthwise

[unique cave]

Im not sure if im able to explain why that happens but thats very usual on collider edges. Im not sure if theres any ways to prevent that. Decreasing physics timestep could help bit but thats not going to be perfectly smooth either.

You could also try different collision detection modes but iirc thats not helping either

[barren charm]

I just learned today that slowing Time.timeScale causes also slows Time.fixedTimeStep. Is there a clean work around for this? (Edit: mistyped fixedTimeStep as fixedDeltaTime)

I want to create a slowdown effect, but because the Physics updates less times per second than the frame rate does it makes the game look like it's lagging. I'm just wondering if there's a easy way to avoid this

[timid dove]

Turn on interpolation for your rigidbodies

[wispy tinsel]

man, 3D physics are extremely fun

so:
this is supposed to be float3 impulse
dashpot.strength * (posB - posA) + dashpot.damping * (lvB - lvA)
I get the part in posB and posA substraction, but what exactly is happeneing in lvB and lvA substraction?
lv - linear velocity

and why is it added to delta position?

[supple sparrow]

I'm tired but looks like it's your acceleration

accel is a delta in velocity
velocity is a delta of position

• some damping for friction probably

and .strenght is the force of your impulse then

this snippet of code suffers some clarity. Could use some intermediate variable names to be understood at a glance

[lapis plaza]

@tender flower that tutorialset had numerous logic flaws, no idea if you get anything functional by following it

Basic raycast suspension in the nutshell: trace rays from preset suspension points in you main rigidbody and trace them downwards from the main rigidbody transform. Then use spring-damper physics equation to compute the forces for each wheel: https://gafferongames.com/post/spring_physics/

There is way more to making proper vehicle suspension but that should get you going

[wispy tinsel]

that snippet is official Unity Physics sample xD
But I get the idea now, thanks

[supple sparrow]

Haha I guess they were going too fast and didnt clean up the code 🙂

[wispy tinsel]

anything related to physics in their samples is really hard to read

[supple sparrow]

Yeah I agree, so much boilerplate to dig through, you don't remember what you were looking for in the first place

[lilac garden]

My player has a CapsuleCollider and it walks over BoxColliders. However, OnCollisionEnter, the ContactPoint normal is not Vector.up. Instead, it prints vectors such as (-0.8, 0.6, 0)

[grizzled jacinth]

this feature / bugfix in Unity 2021.2.8 may be of interest to someone

Physics: Added a new contact modification event to differentiate CCD and discrete callbacks. (1372526)
https://unity3d.com/unity/whats-new/2021.2.8

[old seal]

I have this trouble where if I set the player's position to zero, the line renderer aligns exactly with the mouse cursor, but when I move the player's position like at the top of the screen it creates a weird distance between them like the image I attached (the mouse is the circle below the line). Any idea what's causing it?

Never mind, I figured it out.

[north linden]

anyone knows if meshCollider convex-hull meshes need normals ?

I got a convex hull generator that is not generating normals but it seems to be working fine so far... wonder if that's a problem

[meager coyote]

"Optimization tip: If a Mesh Collider only uses a Mesh, you can disable Normals in Import Settings, because the physics system doesn’t need them."

[timid dove]

In fact the only thing the convex hull needs is the vertices

[strange valley]

I need some help. Does anyone know what is causing this?

[sonic lily]

Trying to mess with some stuff. I thought I could roll a ball down a ramp easier than this.. but no matter how far it drops from it stops here..

[neat coral]

what values did you put for friction and bounce?

[sonic lily]

I ended up using .2 for both and 0 bounce but the friction combine really help me get alot more roll

[unique cave]

High friction + low drag/angular drag would probably make the ball keep its velocity better

[waxen dagger]

Hello, does anyone have experience working with DOTS and havok. My balls seem to be ignoring collision with the walls and just pass through 😦

[supple sparrow]

Hmmm I don't see anything wrong in the code after a very quick glance, but something I wouldn't do like you is having multiple collider types on the same gameobject (trigger AND collider)

[sonic lily]

Drag is 0 and Angular drag is 0.05 I can try raising the friction a bit, but I think it slowed more when friction was higher than these values.

[unique cave]

if the ball rotates, friction shouldn't slower the ball.

it would just make it feel more natural because it makes it roll faster

[sonic lily]

the ball does not make it down the path with 0.3 friction but at .2 it will make it

Static friction is what it takes to move it from a stopped state? and Dynamic is from the state when it's already moving right?

[unique cave]

yes

[unique cave]

then you probably have to decrease angular drag

[unique cave]

if the ball doesn't move relative to the path (only rolls), friction shouldn't really matter

[sonic lily]

it rolls but when friction is at .3 the sphere gets stuck

[unique cave]

weird

[sonic lily]

🤷‍♂️ still trying to figure it out.. I wish I knew what made it weird or not.. lol

[unique cave]

have you tried decreasing angular drag? because it's sphere, angular drag should actually be 0 and drag should have some small value. (there should also be rolling resistance which PhysX doesn't simulate automatically)

[sonic lily]

Looking at it now.

angular drag is at 0

Does seems to react to slopes better with angular drag at 0 and drag at .1

[mighty sluice]

has anyone tried setting the rigidbody.inertiaTensor manually in script in 2022?

editing it is apparently freezing the rotation of rigidbodies

correction: editing the inertiaTensor while rotational constraints are active means that when you deactivate the constraints it will still be frozen rotationally.

actually im not sure anymore

it seems like if you set the inertia tensor on the same tick that it is constrained on, then it will bork

[strange valley]

Yeah that was the problem. I was using a collider for grounded detection instead of the default mesh collider

Ty though for responding!

[timid dove]

I wouldn't be surprised if setting inertia tensor kills the current angularVelocity

[real barn]

Hey! I kinda need help with some very basic physics problems applied to unity, could someone help me?

[real barn]

There are 3 scenes I have to make. The first one is a spherical projectile that is launched by a force (set in design time), the second one is a sphere that has to go through 4 checkpoints and accelerate and decelerate when getting away/ near a checkpoint, at the end it should return to its starting pos. The last one is some kind of 2D game.

[long root]

I would like to create Realistic physics like the first video.
What I managed to achieve so far is in the second video
How can I improve the whole?

https://we.tl/t-8DKDdcoPRt

[waxen phoenix]

Hi! Im trying to create procedural meshes that require complex mesh colliders. Unfortunately, each time I change something in the mesh and reassign it to a mesh collider, it appears to trigger a very lengthy baking process that recalculates everything having to do with the mesh

Is there any way to bake smaller meshes independently, combine them, and assign them to a mesh collider?

My goal is to limit the number of gameobjects while avoiding very lengthy bake processes triggered by small modifications to large meshes. If anyone has any idea of how to do this please reply.

[neat coral]

how many gameobjects are we talking about here?

[waxen phoenix]

I would like to keep the count under 512, but my current method that produces an acceptable physics bake time requires tens of thousands. Gameobjects are too heavy for that unfortunately.

[neat coral]

oh shit yeah that sounds a bit problematic

I'm curious as to what you are doing?

[waxen phoenix]

Generating a ton of procedural stuff. Thats why I wonder if I can bake small physics meshes independently and combine them as needed to minimize gameobjects

[north linden]

@waxen phoenix I don't quite understand what you mean by 'bake' small physics meshes...

if your objects are dynamic then I don't think you can do that, because unity requires dynamic objects to have convex shapes

and joining a bunch of meshes together would break that requirement and also the physics of your game

[waxen phoenix]

So the resulting gameobjects will never move. They need to be concave though. Im just trying to generate the same collision mesh that is generated when you assign a mesh to a meshcollider

I know you can do this with a call to physics.bake

However, I need to make this process take less time. Which is why I'm wondering if you can combine these baked meshes before assigning them to a mesh collider

[north linden]

yes you can do that

take a look at unity's Job system

it's a really fast way of handling fat and long amounts of data

I use it for meshes all over my game

I recently ported Oskar's quickHull implementation to Job + Burst and it's like 100x faster no jk

[waxen phoenix]

Does that system support concave meshes? I mean would you mind sharing some snippets of pointers on how to do this?

[north linden]

ok hold up

can I post code here ?

[waxen phoenix]

I think you can but there are websites for snippets, give me a second

I mean try https://wtools.io/paste-code but really any sharing website will do

[north linden]

https://wtools.io/paste-code/b8Tz

it's not going to compile as I haven't tested it

but that's around what you would want to do

also, you actually need to install the proper packages (Job system + Burst + Collections)

[waxen phoenix]

Thanks, I'll take a look. Pointers are enough I'll clean it and get it running.

If it works for what I intended I'll let you know.

[north linden]

ok

[waxen phoenix]

So, it doesn't work. If I combine the meshes and assign them to a mesh collider, the physics mesh gets rebuilt @north linden

It was worth a shot though

Problem is I don't have Unity's source code to see what it is doing and how I can get around it

There doesn't seem to be any way of doing what I want in Unity, only Unity dots but at that point you might as well be on a different game engine

[mighty sluice]

im 99% sure it's a legitimate bug; when the inertiaTensor is set with rotational constraints active, and then constraints are turned off, rotation is still locked

[timid dove]

submit it

[mighty sluice]

yea i ended up submitting a report

it's one of those ultra-niche issues, but it might be useful to understand what is causing it

my guess is that there is some internal inertia caches that are scaled to infinity when constraints are used, and since i am setting the inertiaTensor once by script, the usual logic that handles inertiaTensor resets don't trigger like they normally would

[barren charm]

I'm having a problem with TimeScale again 😅 It has to do with TimeScale changing Fixed Timestep. When I pause my game I set TimeScale to 0, my vr hand tracking breaks because its updated in FixedUpdate which gets called 0 times while time scale is 0. Is there anyway to change timescale without effecting how often FixedUpdates get called?

[mighty sluice]

a different solution would be to update your trackers outside of fixed update

[karmic thorn]

is there a way to find that red dot with vector properties?

[timid dove]

no

[timid dove]

What information are you starting with

[karmic thorn]

I have v, k and w

they are vectors

starting from the origin

and I know the red dot is on the perpendicular line projected from the top of v

[timid dove]

w is - the orange vector?

I'm not sure w is useful here

[karmic thorn]

me neither haha

I just bring all I thought could help

I know there's a solution using trigonometry, but I want to do it without it

[timid dove]

idk about using vector properties

but certainly with some trigonometry

you have a triangle with all three angles known, and you have the length of one of the sides

I think you can probably find the length of the other two sides from there

especially since it's a right triangle

soh-cah-toa applies

gimme a sec...

[karmic thorn]

yes I have the v length

[timid dove]

yeah, and you have thje angle between V and K which is just Vector3.Angle(v, k)

float vLength = v.magnitude;
float angle = Vector3.Angle(k, v);
// cosine of angle = adjacent/hypotenuse. vLength is adjecent
float cosOfAngle = Mathf.Cos(angle * Mathf.deg2Rad);
// hypo = adj/cosangle
float hypotenuseLength = vLength / cosOfAngle;
Vector3 result = k.normalized * hypotenuseLength;```

I think this is what you need?

if my trig is correct @karmic thorn

[karmic thorn]

yes

thanks

[bleak umbra]

Thought about it and came up with this based on cosecant of angle A in a unit circle is 1 / sin(A), looks equivalent to praetor's on first glance. (was bored during breakfast, 😉 )

float CosecantProjection(Vector3 v, Vector3 k) => (1f / Mathf.Sin(Vector3.Angle(v, k) * Mathf.Deg2Rad)) * v.magnitude;

Vector3 CosecantPoint(Vector3 v, Vector3 k) => (1f / Mathf.Sin(Vector3.Angle(v, k) * Mathf.Deg2Rad)) * v.normalized;

[lilac garden]

    bool IsGrounded()
    {
        // genericCollider is a Collider base class component
        Vector3 boxSize = new Vector3(genericCollider.bounds.size.x, genericCollider.bounds.size.y, genericCollider.bounds.size.z);
        float maxDistance = genericCollider.bounds.size.y / 2 + .01f;
        bool isGrounded = Physics.BoxCast(transform.position, boxSize, Vector3.down, out RaycastHit hit, transform.rotation, maxDistance, groundMask);

        // DEBUG
        Vector3 drawBox = new Vector3(boxSize.x, maxDistance*2, boxSize.z) / 2;
        ExtDebug.DrawBox(transform.position, drawBox, Quaternion.identity, Color.green);

        return isGrounded;
    }```
First time using BoxCast. I'm having trouble understanding why it doesn't return true, when the box is intersecting the ground collider
(NOTE: it returns true if the player is less on the edge of the ground collider, but not if it's almost falling, like in the picture)

[bleak umbra]

Is this supposed to be using 3D physics? Is the ground a 3d collider?

[lilac garden]

Yes, core mechanic needs the game to be in 3D.

[bleak umbra]

maybe your debug drawing is incorrect?

[lilac garden]

maybe the BoxCast maxDistance is incorrect vs the drawBox, but still, traveling too much would still return a groundMask hit, no?

[bleak umbra]

you are also not debug-drawing the orientation of the boxcast

[lilac garden]

    bool IsGrounded()
    {
        // CAPSULE COLLIDER
        Collider collider = genericCollider; 

        Vector3 halfExtents = new Vector3(collider.bounds.extents.x, collider.bounds.extents.y, collider.bounds.extents.z);
        float maxDistance = .1f;

        // groundMask is layer number 7. groundMask = 1 << 7
        bool isGrounded = Physics.BoxCast(transform.position, halfExtents, -transform.up, out RaycastHit hit, transform.rotation, maxDistance, groundMask);

        return isGrounded;
    }

    private void OnDrawGizmos()
    {
        Gizmos.color = Color.blue;
        Gizmos.DrawWireCube(transform.position + (-transform.up * .1f), genericCollider.bounds.size);
    }

I think this is right. I'm getting isGrounded = false 100% of the time. It never returns true.

[bleak umbra]

sorry, i don't have any additional ideas but to check that you haven't missed any of the obvious things (enabled, values correct, assumptions all true). but i suppose you have done that multiple times already.

[lilac garden]

I removed layermask and changed the distance to 2f (capsule halfExtent height is around 1f). Now it does return true, but only when I jump (mid jump). If I'm on the platform it's always false. This function is on FixedUpdate running without being in IFs statements. I don't really understand how BoxCast works

[bleak umbra]

one more: is the box you are casting actually aligned the same way as the capsule you are deriving it from... you are adding the transform.rotation but that isn't necessarily the capsule's orientation (might be 90° off)

[lilac garden]

Capsule Collider is on the same obj as the script that casts the Boxcast. Sometimes the obj's rotation can vary, but transform.up is always (0, 1, 0)

[bleak umbra]

so passing a Quaternion.identity into the boxcast doesn't change anything?

[lilac garden]

bool isGrounded = Physics.BoxCast(transform.position, halfExtents, -transform.up, out RaycastHit hit, Quaternion.identity); this returns a hit only when jumping, altho the Boxcast is running on fixed update.

[bleak umbra]

Raycasts will not detect Colliders for which the Raycast origin is inside the Collider.

i'm guessing your boxcast origin needs a small offset which the jump provides

[lilac garden]

Ah I think this was the issue. The BoxCast was spawning already penetrating the ground colliders.

[scarlet bluff]

can someone tell me why the leg goes through the skirt, even though I set colliders for the legs in the dynamic bones?

[serene thorn]

Hey all! What arcade style physics libs do you recommend? There’s of course wheel colliders vs a sphere and libs Edys Vehicle Physics. I’m going for a feel similar to Smashy Road Wanted.

[dire quartz]

hey everyone, I have a small problem. I have an Box Collider trigger above my Teleportation Area, the problem is if I want to teleport into it the teleport control thinks its an object and wants to teleport me on top of it. How do I keep the box as a trigger but ignore it when teleporting? E: Got it! Change Trace Layer Mask on Teleport Function and exclue Box Collider Trigger

[stuck bay]

any reason why tilemapcollider2d doesnt work but boxcollider2d does work on seperate tiles?

driving me nuts

[frozen aurora]

how can i use a set jump height with an impulse rigidbody addforce?

[timid dove]

wdym by "it doesn't work"?

[stuck bay]

My character just walks trough it. I fixed it now tho. No clue how

[karmic thorn]

hi

I need the blue vector to displace like the magenta but reaching the yellow
intersection
they are the reflection of the black long vector
the magenta is being displaced like
magenta = blue + longBlack.dotProduct(shortBlack)
so the real question I think is how long is that green segment

[slate lily]

So I have this box cast to check if iam grounded but sometimes it bugges and keep me ungrounded and grounded very simple box cast at 1,1.1,1 size on hit iam grounded else not so idk what the prob

[hasty quail]

How would I go about adding a limit to much speed you can add via continuous AddForce?

Most solutions I find just ClampMagnitude rigidbody.velocity but that's not what I want, since that always sets a max speed you cant pass, even if you were to say, go on a jump pad or fall really fast

I need to figure out a way to clamp the amount of force you add from moving so it wont go above max speed

Any ideas?

[timid dove]

It's a bit more complex but what I do is project my continuous force into the current velocity vector and check if it will put me above the speed limit, and if so I remove the component of the force vector that is in line with the current velocity before applying it

It requires you to be quite comfortable with vector arithmetic and projection etc

[hasty quail]

I just wanted to make a roll-a-ball

[hasty quail]

By project do you mean Dot?

[timid dove]

No I mean vector projection

[harsh kayak]

Hello, how do I calculate angular drag?

eg, If I have a ball of 3kg weight rolling on a flat surface how can I

calculate the float number of angularDrag of my game object

[unique cave]

um... perfect ball doesn't have angular drag. you're most likely looking for rolling resistance. using angular drag may not be the correct way to simulate rolling resistance (i'm not aware of the correct rolling resistance formula tho)

[rich elm]

Not sure if this would belong here or not... if someone was doing a game with body sliders (make the arms bigger/smaller, add muscle/remove, increase/decrease chub all around) kind of stuff how exactly is that handled? Especially if you want to keep it consistent and prevent clipping from like, armor, grapples, etc?

[wispy tinsel]

how to get shortest distance between point X (cube on picture) to some Axis (vector on picture) in space?
So it's shortest distance not between 2 points, but 1 point and axis.

[oak depot]

Hello!

I have the following problem.

I have a game object with a box collider and an animator component.

This game object is basically a door.

When I push a button, it goes down when it opens or back up when it closes.

Problem is:

If I put a box with a rigid body component on top of the door when it's opened and then push the button in order to close the door, it goes right through the box.

[wide nebula]

Why does your door need a rigidbody?

[oak depot]

The box I put on top of the door has a rigid body component.

The door itself only has a box collider and the animator component.

[wide nebula]

Why do you mean by "on top" of the door?

[oak depot]

When I open the door, it lowers itself and I can place the box on top of it.

[wide nebula]

So you want the box to prevent the door from closing again?

[oak depot]

No. When the door closes, it raises back up. If a box is on top of the door when it raises, it should push the box aswell.

Instead, it just goes through the box.

Here is a video if you want to see what I'm talking about.

@wide nebula?

[frigid pier]

@oak depot You should use mp4 format so video would embed.

It's less likely someone would see it if they need to download it

[wide nebula]

As above, but I downloaded it anyway lol.

The thing is, you need to be moving your door with physics if you want it to physically interact with objects.

[oak depot]

True. I haven't uploaded a video on Discord for so long that I forgot I should use the .mp4 format.

[oak depot]

So if I move an object by animating it, collisions will still be ignored.

Noted! 🙂

Thank you!

[wide nebula]

Right, because animations move by transforming the position (ie, teleporting it each frame).

So you kind of have to decide what to do here. If causing a block to jump out when it's hit by a door is not really important (in that, you were basically just trying to handle an edge case), you could also handle it by not allowing the door to be closed if it detects an object on it. Otherwise, you'll need to add physics to your door.

[unique cave]

this may not be the fastest but this is what came to my mind. if you have any point A on that axis, you could use vector projection like this: Vector3.Distance(A-X, Vector3.Project(A-X, Axis)). I have no idea if this even works but I hope so.

[timid dove]

I would use this https://docs.unity3d.com/ScriptReference/Plane.ClosestPointOnPlane.html

[wispy tinsel]

Actually I figured you just need to calculate delta vector on 2D xD

multiplier of that vector would be distance

I didn't check tho

[ancient root]

hi, I have a very big problem, I want to make a 2D ragdoll, and I had following this tutorial https://www.youtube.com/watch?v=bCkvh0lZFVk... but my character just explodes

🥲

i'm using the unity 2020.3.23f1 version

[desert wave]

https://www.youtube.com/watch?v=EYcVY03Mk_E

maybe will help

[wispy tinsel]

nah, it's different question

my question was actually super simple

[supple pawn]

I think you would get a point on the axis that's on the same height as the point X and just get the distance

[wispy tinsel]

Yep

[hasty quail]

By continuous force, do you mean rb.velocity + force2add?

or just force2add

[hasty quail]

I am so close to figuring out the math D:

[hasty quail]

@timid dove I did this and I'm not sure if I did it right to cap the speed you can add

It does cap the speed when going in one direction, but making sharp turns is now very sluggish and makes a U-turn, and doing so also lets you break past the speed limit

I think I accidentally recreated Source-engine air-strafing

Nevermind I fixed it!

Now there'll be no weird turning nonsense but speed is properly clamped without directly touching rigidbody velocity!

[hasty quail]

One question though, if we break past the speed limit, will inputting movement in the direction break your force?

Might test that myself

[oak depot]

@wide nebula, thanks for explaining to me how the animations actually work. I added a rigid body component to the door and made a script to control its movement. This is how it looks now.

[wide nebula]

Oh nice, that's pretty cool

[strange canyon]

I'm currently working on this motorcycle game and I'm not sure if I'm coding my road right. Currently I have a prefab that I'm just scrolling the length of plane while the motorcycle is at the center. Is this the correct way to make an endless road? Or should I have a long plane that extends the scene and have a material be animated on the background for all the lines in the road? Right now when I put cars on there sometimes they fly off and I'm thinking the reason might be because I'm moving all these road objects under them and they're getting caught in the cracks and getting projected into the sky

[compact talon]

currently working on a 2d platformer and i have an issue where, whenever the player lands on the ground, the sprite very briefly goes through the floor, which looks really weird

dont know it anyone else has had this issue, please help!

im just using gravity to simulate jumping and falling

[desert wave]

does it happen when the script is not running?

[compact talon]

im running the scene

so it should be??

its when i jump and fall down, it briefly glitches through

[desert wave]

put the player 5 meters above the ground and deactivate the player script or scripts

just wanna make sure that is a script

or not

[compact talon]

i dont think it is clipping anymore?

its a bit laggy to tell but it doesnt seem to

if its not scripts, what should i do

[desert wave]

so its the script affecting it?

or is the physics of the object/ground?
or could check your pc

[compact talon]

it might be

if it is, what can i do

i dont think theres anything that could affect it

[oak depot]

Hello! I'm want to display the velocity magnitude of a rigid body inside the console when I apply a force to it but it returns 0.

I looked on forums but haven't found anything to help me figure out why this happens.

Anybody got an idea why this issue occurs?

[heady merlin]

is there away to reduce the cost of rigid2d physics? i don't want my zombies on top of each other but with it on i can only have about 300 with it off i got upto 1000 before it started to get below 60fps

[jovial wraith]

https://docs.unity3d.com/Manual/iphone-Optimizing-Physics.html

[raw stream]

hey guys

so i did this

and i want the coins to fall on the grass

so i did this for the coins:

right

i did the grass like the tilemaps kinda thing

and did this to the tile maps:

but it ain't working

whats the problem

why

coins fell to the void of vikings

like

why

PLEASE HELP

[unique cave]

Does the coins also have colliders?

[raw stream]

nope

wait i have to put it?

[unique cave]

They should

[raw stream]

ok

[unique cave]

Unity handles collisions only between colliders (and rigidbodies, static objects doesnt need rb tho)

If object doesnt have collider, it cant collide with anything and other objects cant collide with it

[raw stream]

it be still falling to the void of vikings

i did this for coins:

[raw stream]

NO ONE helping

[wide nebula]

Don't complain.

Start by removing the rigidbody from your ground, it's not needed.

[deft pike]

Does anyone have an idea why I get randomly stuck sometimes? I know when it happens which is right before I cross over from 1 box collider to another, but I am using a grid to place the blocks so it is 100% the same size and everything. I am trying to keep my boxcollider over a capsule collider if possible but if that is the only way to fix it then I will go for it. or just make it float above the ground but I wanted to avoid it because placement became semi inconsistent

https://cdn.discordapp.com/attachments/497874004401586176/934393374327324702/unknown.png

[pine warren]

This is just how physics behave in Unity. Perfectly aligned colliders still stop or apply weird forces when you cross over. If you roll a sphere collider over two boxes that are perfectly aligned and static, the sphere will usually make a small jump as a result

"rounded" colliders dont usually stop though, they just excibit that small jump, usually not even noticable (unless you go fast, then you make insane jumps for unknown reasons)

[deft pike]

ah okay, in that case I will just make him float above the ground again

let me ask another question then because I had it before, when shooting a raycast from above the ground towards the ground I am trying to use Rayhit.Point to get the exact height that the block is at to jump on it, so I can reset the height and keep the robot at that level. Now I do not always get the same height. Do you have any idea why that is then? https://cdn.discordapp.com/attachments/497874004401586176/933993127587512361/unknown.png

        RaycastHit2D[] colliders = Physics2D.BoxCastAll(m_GroundCheck.position, m_GroundCheckBoxBounds, 0, -Vector2.up, m_GroundCheckBoxBounds.y, m_WhatIsGround);
        for (int i = 0; i < colliders.Length; i++)
        {
            if (colliders[i].collider.gameObject != gameObject && m_Rigidbody2D.velocity.y <= 0)
            {
                m_Grounded = true;
                m_HasGrappled = false;
                m_CoyoteTimer = m_CoyoteTime;


                m_JumpDustParticleSystem.position = new Vector3(gameObject.transform.position.x, colliders[i].point.y, m_JumpDustParticleSystem.position.z);

                if (!wasGrounded)
                {
                    m_OnLandEvent.Invoke();

                    m_Rigidbody2D.gravityScale = 0;
                    m_Rigidbody2D.velocity = new Vector2(m_Rigidbody2D.velocity.x, 0);

                    RaycastHit2D rayHit = Physics2D.Raycast(new Vector2(colliders[i].point.x, m_GroundCheck.transform.position.y), -Vector2.up, float.MaxValue, m_WhatIsGround);

                    print(rayHit.point.y);

                    transform.position = new Vector3(transform.position.x, rayHit.point.y + (m_BaseCollider.size.y / 2) + m_GroundCheckBoxBounds.y, transform.position.z);
                    m_Rigidbody2D.velocity = new Vector2(m_Rigidbody2D.velocity.x, 0);
                }```

(also I know it is a bit double to do a raycast from the x position of a boxcast but it gave me an a lot better positioning with less variation so until I have figured out a better way, that is it)

or does this not count as a physics problem? 🤔

[compact talon]

hello, heres a video on my problem with sprite clipping

and idk how to fix it

im using unitys gravity for movement

[livid sparrow]

the car drifts too much can anyone help me

[atomic harness]

Maybe this is the right place to post this, i have the movement created for my character (although its extremely clunky and bad) and sometimes the sprite for the player just falls on its sides, on really bad ocasions it can even just do a full 180 flip (ignore the typical assets from kenney, just wanted something to look at while prototyping that wasnt a white square)

How do I stop this? Is it code related or just physics settings?

[nocturne coral]

Hello, when I turn my camera the player doesn’t turn

What can I do for it??

[nocturne coral]

You probably have to freeze rotation from your player’s rigidbody

[atomic harness]

oooh ofc, wow im dumb lol

thanks

[nocturne coral]

np!