⚛️┃physics

[magic crow]

because although the car is teleporting, it can't go where the sphere can't go

but ok, here is where I got to using real physics

I have an issue with wheel colliders catching on terrain. At first I thought it was the box collider, but I tried adding some other colliders, then removing them all, and it still happens.
The way it manifests is while travelling over uneven terrain, if it catches, the vehicle will spin around where it's caught, or on launching over a slope, it will turn. I don't really have any clue how to counteract it, any suggestions?

^ I posted this before and the advice I got was to go back to using the sphere method

[magic crow]

this doesn't make any sense to me. I added child object to the sphere consisting only of a box collider in its own collision domain, called "ignore", and set the collision layer in project settings to collide only with "static objects". There is one object in that collision domain in the scene. Yet switching that box collider on and off changes the way the car interacts with everything else. The car can't even move until you switch the collider on and off once

Even if I set the "ignore" layer to not collide with anything, it still does, and affects the car as a whole

[timid umbra]

Hi, I am modding a 2D game (RimWorld) and I added a flamethrower particle system. Works great and now I want the flames to not go through the 2D walls. I can hook into whenever a wall piece is placed/removed (square cell) and my question is: what is the most efficient way to design the collider? The simplest approach to instantiate a cube with a box collider for each wall tile (on a 250x250 map) made it quickly ran out of resources just for a bunch of wall pieces.

A bit like https://forum.unity.com/threads/when-is-too-many-box-colliders-too-many-box-colliders.29574/ ?

Ah, its also not possible to have one object with many box colliders: https://answers.unity.com/questions/188775/having-more-than-one-collider-in-a-gameobject.html#:~:text=You can add multiple colliders,for physics and one not.

Hmm, its actually possible to have an empty GameObject with many BoxColliders on it. At least in Unity Editor it works, so now I need to script it

[polar leaf]

Hello, I'm trying to rotate a missile using torque so it homes in on a target, but it's not working. Here's my code:

        Quaternion desiredRotation = Quaternion.FromToRotation(transform.forward, desiredDirection);

        Vector3 torque = new Vector3(desiredRotation.x, desiredRotation.y, desiredRotation.z) * desiredRotation.w;

        float appliedTorque = angularForce * Mathf.SmoothStep(0f, 1f, Mathf.InverseLerp(0f, angleDecay, Vector3.Angle(transform.forward, desiredDirection)));

        _rigidBody.AddTorque(torque * appliedTorque * Time.fixedDeltaTime);````

I think the problem is on the ´torque´´ variable but I can't seem to find a way to find the torque that corresponds to a quaternion rotation

[timid dove]

Does desiredRotation.eulerAngles work?

but yeah the way you have it now is definitely not right

[stuck bay]

my player is automatically moving in unity

what should i do

[heavy summit]

Does anyone know why my character is jittering when they walk https://gyazo.com/9e44e9a8f3620da2f583a2c58538b4f8

nevermind, i had movementhandler function called in update rather than fixed update for some reason

[vivid gazelle]

Question, if I have a MeshCollider whose layer can't interact with any other layer (even itself) will Unity consume performance in order to test for collisions on each FixedUpdate. I want to use the MeshCollider only for raycasts, nothing else

[tight oriole]

i have some marble falling onto a spinner but instead of being launched they either clip through it or get pushed sideways

[timid dove]

at worst it will do bounding box calculations

which are super cheap

[jolly brook]

Hey there, so I have three states for a defensive enemy: Flee, Wait and Pursuit. In the flee, it runs away from the player, in the pursuit it follows the player. The wait state is the in-between where it just does nothing. It works fine except when it's on a slope, then the enemy just starts to tumble because nothing is being done with the RigidBody, so I am guessing gravity takes full effect then. How would I make sure an enemy can also just "wait" on a slope without falling over?

[timid dove]

You might need a separate "wait-on-slope" state or just code in the Wait state that resists such movement

[jolly brook]

Yeah, that's what I was thinking of doing. How would you go about disabling any movement in the wait state?

[timid dove]

make it kinematic or add constraints on the Rigidbody

or disable gravity and set velocity to 0 if you want it to still be able to get knocked around by other stuff

[jolly brook]

Thank you! That seems to have worked 🙂

[placid hatch]

Hey i'm quite new and i' m facing an issue, my character keep falling through my terrain even with a character controller on. Character Controller isn't suppose to detect collision ?

[timid dove]

How are you moving the character (e.g. CC.Move)?
Does the terrain have a Collider?

[placid hatch]

I use the CharacterController.Move method and yeah my terrain have a collider i generate a cude with a boxCollider to test and he collide but not my character

[timid dove]

Did you attach any other colliders or a Rigidbody to the player character?

[placid hatch]

Yeah a Rigidbody to apply gravity

[timid dove]

You can't use Rigidbody and CharacterController together

they are separate and competing movement strategies

[placid hatch]

Oh !

Ty i struggle for 2 hour now and you solve it in 2min thanks really appreciated !

[timid dove]

To apply gravity with CharacterController you should keep track of the character's velocity yourself in your player movement script and adjust the Vector that you pass into CC.Move accordingly

[placid hatch]

Oh ok i see

thanks for you r time and investment, you helped me a lot !

[stuck bay]

struggling with making smooth player-on-planet movement

in scene view i have smooth planet movement

but seems whatever method i use, i get shaking in gamemode
https://i.imgur.com/G4WuQ8Z.gif

(interesingly enough this one was 1. parented to planet, 2. only setting pos with .loclPosition, 3. constantly at the same localPosition without change

and yet it did this

[placid hatch]

try enabling interpolate, i'm new i find this solution here if you want some documentation
https://answers.unity.com/questions/1682251/how-to-prevent-camera-jitter-when-moving-my-rigidb.html

[stuck bay]

i do have that yeah

it helps

[placid hatch]

happy to help then, good luck with your project !

[rancid socket]

This code is supposed to create an explosion that only blasts objects in it line of sight. the explosion works but it blast objects that are not in line of sight?

        hasExploded = true;
        Instantiate(effect, transform.position, transform.rotation);
        foreach(Collider col in Physics.OverlapSphere(transform.position, blastRadius)){
           if(col.GetComponent<Rigidbody>() != null){
               RaycastHit hit;
               if(Physics.Raycast(transform.position,col.transform.position-transform.position,out hit,Mathf.Infinity)){
                   if(hit.collider == col){
                       col.GetComponent<Rigidbody>().AddExplosionForce(force,transform.position,blastRadius);
                   }
               }
           }
        }
        Destroy(this.gameObject);
    } ```c#

[supple sparrow]

raycast origin should be in world coords ?

Nah should work like that

[lapis root]

excuse me, does anyone know why this happens?
I'm using Wheel Collider on all wheels, and rigidbody on the body

[foggy rapids]

looks like all the weight is on one side

[lapis root]

the configuration of the wheel colliders are identical, and the center of mass of the car is in the center, without tilting right or left

I have already tested it on 2 cars, with different characteristics, one big and one small, both happen the same thing (Tilt to the left)

[timid dove]

Hard to say without seeing more of your setup

[gentle cape]

COLLIDERS ....

So for some reason my rigid bodies are colliding with triggers ... or better said triggers act as colliders .... is there a way to brute enforce these damn things to just not collide?

I tried putting them in layers of which I turned of the collisions ... but still my objects keep colliding even though they are set to trigger .

To be clear I have areas on the map which are triggers and when objects land on these areas they get awarded points based on trigger functions

[timid dove]

you're saying your objects are physically bumping into triggers?

and bouncing off them etc. ?

[gentle cape]

Yes they are...very annoying

[timid dove]

Are you sure you don't have some stray colliders around that are not triggers?

[gentle cape]

I have player objects which are regular colliders ... and passive scene objects which act as triggers ... no other colliders

[timid dove]

Just to be sure try typing this into the search bar in your hiearchy window:
t: Collider

go through and make sure you can account for all the colliders in the scene

and double check your trigger colliders to make sure they are-in fact- triggers

[gentle cape]

No colliders active ... what could this be?
I tried decreasing teh timesteps but even though that kinda helped it also caused some collisions to be missed and I also switched from and to several different rigid body types (discrete/interpolate etc ) ...but it does not help... is there no hard way to stop this from happening ?

[timid dove]

I've never heard of it happening at all

so not sure

[gentle cape]

this is how it looks

[timid dove]

Disable that 20 points object completely

see if your puck still collides

[gentle cape]

Disabling never works (don't quote me on it but I read somewhere that Unity still calculate disabled triggers and disabling really never worked for me)...when I delete the item it doesn't collide, but as I need the object that is kind of a no-no 🙂 .... anyway I just reset the rigid body to none + discrete and lowered the fixed timestep to 0.01 and it is a lot better now .... still not very smooth...but at least the obvious bounce is out

[light jasper]

Unitys units are all metric right?

[gentle cape]

YEah and in meters and KG 😉

[light jasper]

Cool

Next question: how is drag on rigidbodies integrated? Is the value the coefficient

[gentle cape]

don't really know ... I just tend to play with values until it feels right ... I don't think they use real world values, but more liek a normalized 0-1 value which is more of a relative scale

[light jasper]

Hrmm

Theres no information on the docs either

[gentle cape]

I believ eit is all based on PhysX ...maybe they have more info ... but I think they work with rough approximations ... as dynamics are expensive and games are not used for scientific double floating point precision calculations so that is normally good enough ... again I would just play with settings until it feels right

[light jasper]

Well, I'm actually trying to use it for basic simulation

Thanks for the information on PhysX though, will check out

[timid dove]

so technically Unity's units are just "units". But the physics engines it uses (PhysX and Box2D) are mapped as 1 unity unit = 1 meter

[hollow echo]

Most falloffs in the engine (like lighting) also assume 1 unit = 1 m

[light jasper]

Sweet thank you

[timid dove]

IIRC this is true for URP/HDRP but the built in render pipeline uses some kind of weird magic lighting falloff that wasn't really physically realistic?

[hollow echo]

it just used a texture

[timid dove]

oh?

[hollow echo]

it wasn't realistic though, you are right

[timid dove]

This may be a weird worry - but sometimes I think about how heavily everything in Unity (and a lot of applications) is optimized for attempting to simulate the real world, when there are so many perfectly good imaginary universes we could be setting our games in 😄

[visual furnace]

Math problem
If 2 Cars are both moving towards east,
with Car A being 300 Meters ahead of Car B,
Car A with a Velocity of 40 m/s with a Decreasing Acceleration starting at 10 m/s ~ 0 m/s
Car B with a Velocity of 50 m/s with an Increasing Acceleration starting at 15 m/s ~ 30 m/s
at what time will Car B catch up to Car A?

[timid dove]

not enough information

you haven't described how quickly the acceleration is increasing or decreasing

actually don't really understand your description of Decreasing and Increasing acceleration at all

[visual furnace]

Sorry, I don't really know to say it properly.
I don't know if this follow up, will help you understand it
Increasing acceleration would be like Gravitational Acceleration
Decreasing acceleration would be a reverse of that

and let's just say that Decreasing Acceleration is Decrease by 2m/s per Second
and Increasing Acceleration is Increase by 3m/s per Second

[tidal linden]

would there be any reason for a kinematic rigidbody being moved with interpolation to act differently after a scene reload without a script explicitly telling it to? lol i know this is a weird question but my player seems to be losing contact with the platform but it works exactly as intended until the scene reloads, very very odd.

[compact solstice]

@rancid socket Did you solve your issue with explosion? I was just thinking maybe you need to add a layermask to your raycast 🙂

[rancid socket]

I did, it was because the effect I instantiated also applied force even without the code. Didn't need to touch layermasks

[magic crow]

I have an issue with transform.rotation because it's clipping my object through the terrain and clipping, but when I try to use AddTorque, I dislike the inertia it produces

is there an option that will rotate a rigidbody with a force, but no inertia?

[timid dove]

AddTorque is supposed to be exactly that

unless you mean "rotational" inertia

If that's the case you can just use MoveRotation

[foggy rapids]

you can do a BoxCast with the dimensions of your objects' bounds after rotation and undo it if there are results

err, overlapbox

you can do the rotation, perform a sweep test with the current movement parameters and undo it if there are any result

[magic crow]

Thanks both

Let me look at MoveRotation

seems to work now, thankyou

[tidal linden]

I'm moving a kinematic rigidbody with moveposition, with interpolate on. Checking the velocity with a draw ray shows smooth movement. Yet when I reload the scene, the movement gets riddled with 0,0,0s and becomes jittery. I ran checks and interpolate is still on, nothing I can see has changed with the body or my very simple movement script.

I'm starting to think its just a problem with my unity version

[timid dove]

share the code?

[tidal linden]

https://ghostbin.com/paste/F6maZ I also duplicated the platforms a handful of times, and notice that when there's more than 3 in the scene at a time, some of them start to behave jittery, so its not due to the scene reload it seems

also the tracked transform is being lerped in fixed time step... again the platforms work perfectly fine when this doesnt happen lol

[tidal linden]

ill try deactivating rigidbodies in a proximity if its rly a performance issue

[timid dove]

When you do MovePosition I'm pretty sure it doesn't actually set or change the velocity field

Also you're doing this...

    private void Update()
    {
        if (transform.position != trackedTransform.position)
        {
            transform.position = trackedTransform.position;```

so you're moving the transform directly

and jthen also trying to use MovePosition?

use one or the other

Basically I think if you delete your Update() method you'll be better off

[tidal linden]

Oof, that's some major tunnel vision. I think that was meant to place it while setting it up in editor.

Thanks @timid dove !

[sour lake]

So I have a question in regards to character physics, I apologize if my wording is a bit off.

I've been reading up on ways to simulate physics for stuff like cloth, hair, and softbody objects and it seems like their are two options. Either to script it and animate the weighted bones in unity to be simulated during runtime or the second option of simulating them in an animation tool like Blender and exporting it as one animation.

Am I missing understanding the work flow potentially? I'm assuming it's mainly just a trade off between performance and having something more dynamic.

[viral ginkgo]

@sour lake i'd try to get away with bones

a small amount of them

i'd rig them as their own objects seperately (so we dont complicate the character rig)

merge them in my character prefab

and then i'd move the bones with either code or physics

[sour lake]

@viral ginkgo thanks for the input. I didn't think about having them be separate objects. That's a really good idea if I were to go that route. And would you say the end result was worth it?

[viral ginkgo]

I never had any clothlike stuff on my characters

but thats how i'd do it if i were to

@sour lake

i also wonder how you'd move them by code

[sour lake]

Good to know.

[viral ginkgo]

physics is gonna be weird since your animated character is nonkinematic and all

so probably you'd wanna do it in code

its not easy though, and i can't think of a complete solution how you'd manipulate those bones in code

@sour lake

[sour lake]

Hmm I'll keep those things in mind.

I guess a lot depends on the game.

Like if it were more of a point and click or rpg type game where the gameplay isn't necessarily very reactive and physics based maybe I could get away with pre animating stuff. Idk

It could quickly develop the "mmo" effect though where everything seems static

[viral ginkgo]

@sour lake dynamic clothlike effect make it real cool

i think its worth it everytime as long as the game is not turn based or its an rts hah

[sour lake]

I suppose it's worth a shot either way

[viral ginkgo]

1- Acceleration based leaning via head IK target
2- Hip/root vertical movement while taking steps
3- Animate hand and feet via IK targets
4- Dynamic stuff like cloth

@sour lake

And you get some high grade eye candy

these are some low cost tricks but they really make the animation super dynamic

[sour lake]

I definitely want to look into IK rigging that's for sure. When I learned you could have a character actually reach out to a certain object or turn their head to look at something with them my mind was blow haha

[viral ginkgo]

i think IK makes things easier

also you can switch a character model and still make the same animation fit

because you are just animating the IK targets, not the character

[sour lake]

I think thats probably another good reason to look into simulating more things in engine. If I was to simulate it and export an animating for hair physics in blender and then tried using an ik bone for the head in unity that could look weird

Because if it works like I'm assuming you're basically now dynamically animating a base bone while all those little bones for hair aren't and react as if the head is not being adjusted

Or something along those lines

[viral ginkgo]

i don't think it's a good idea to animate clothlike things statically

these little dynamic behaviours make things look good

i even wanted to animate feet IK dynamically, but it doesnt seem to be worth it that much hah

[sour lake]

Heh idk maybe. When it comes to IKs I can see the appeal

[viral ginkgo]

https://www.youtube.com/watch?v=fbCxy-mgNj8
I think it wouldn't look much worse without dynamic feet IK placement

[sour lake]

The stuff that's extra tricky is the cloth and soft body simulation

[tight stump]

Does anyone know how to fix the clipping in cloth simulation?

Player is a character controller

[crimson karma]

very nicee

[inland yoke]

So I'm running into a bit of a physics problem. I'm trying to set up the physics2D matrix so certain objects won't cause triggers to fire except when it hits an object that is supposed to interact with. In this have an Enemy Blockable Attack projectile that I don't want to collide with Enemies but for some reason it still does despite the interaction being turned off in the matrix

What other things can cause this problem? Do trigger scripts ignore the matrix?

For some reason a restart of unity fixed it soooo nevermind?

[neon glade]

I have a cube that is dropped so that an edge that is offset from the center of mass hits a surface that has a slightly bouncy physic material. I expected the cube to start spinning after contacting this surface. Instead, it bounces straight up, without any rotation.

The surface should apply a force in the Y direction that is offset from the center of mass of the cube. I expect rotation.

[timid dove]

did you constrain rotation on the rigidbody?

[neon glade]

No

[neon glade]

It’ll tip over but doesn’t spin when the cubes edge hits the surface

[timid dove]

@neon glade is working alright for me

[magic crow]

If I add my Wheel Colliders to a script using public transform, does Unity know they're wheel colliders? I'm trying to assign the brakeTorque to them and it's not compiling it

[timid dove]

You need to get the WheelCollider component

[magic crow]

I've done some reading and tried following something that was using this:
// WheelCollider BackLeftWheel = BackLeft.gameObject.AddComponent<WheelColliderSource>() as WheelCollider;

[timid dove]

WheelCollider BackLeftWheel = BackLeft.AddComponent<WheelCollider>();```

Try this^

[magic crow]

thanks! 2 secs

ok, this must be something wrong in the syntax - the colliders are assigned as BackLeft and BackRight

WheelCollider BackLeftWheel = BackLeft.AddComponent<WheelCollider>();
WheelCollider BackRightWheel = BackRight.AddComponent<WheelCollider>();

the wheel collider is being assigned as BackLeftWheel etc

and I've tried applying the braketorque to both, but it doesn't like either

no, I commented out the braketorque stuff, so it's something in the assignation

am I missing a library?

[timid dove]

?

Idk what's the error you're getting

share your error and your code

otherwise I'm just guessing

[magic crow]

that should contain everything

It's not giving me an error, I don't know how to get the console back

ah, found it

transform does not contain a definition for AddComponent

[timid dove]

sure it does

what line?

The error has a line number in it

[timid dove]

btw line 45 and 46 you need to remove the word WheelCollider from the beginning of those lines

when you have that there's you're making a new variable instead of using your existing ones that you declared on lines 28-29

[magic crow]

45 and 46

ohh ok

ah I added the two in on 28 and 29 after

right I have it compiling by assigning the two wheelcolliders within the inspector

I was trying to use this: https://wiki.unity3d.com/index.php/WheelColliderSource-CarController and I have no idea about the relationship where it specifies a transform, and then relates that to a collider

[timid dove]

you're looking at an example for something else

IDK what WheelColliderSource is

it's some custom thing they're doing

[magic crow]

Yeah, I couldn't find anything in the manual, weird

thanks for your help again

[neon glade]

No I’m dropping the cube rotated 30 degrees onto a flat surface. Trying to simulate dice falling onto a hard surface.

[timid dove]

That works too

[neon glade]

Hrm. Will send a video when I’m back at my desk. Thanks!

[jovial depot]

Hi 🙂 Im trying to move the car, but when moving from one platform to another (in this case, green to yellow), SOMETIMES the jumps as you can see in the video, but idk why 😢

[timid dove]

https://answers.unity.com/questions/568974/sphere-collider-catching-edges-of-aligned-cubes.html

Try playing with the default contact offset

[jovial depot]

Thank you @timid dove, I will try it 😆

[neon glade]

Here’s the behavior

[timid dove]

do you have any scripts on that thing?

probably a script affecting the rotation

[neon glade]

It’s a third party prefab. I thought the script just detected the face that’s pointing up but I’ll have a closer look.

[timid dove]

Check all the components on it

We know a basic Unity Rigidbody works so it's just process of elimination

[undone nymph]

Physics make me go YESSS!

[viral ginkgo]

Is there a nice way to prevent slipping on angled surfaces with zero friction rigidbody controllers?

[timid dove]

Add your own friction force that perfectly counteracts gravity

[viral ginkgo]

Maybe i should just counter gravity when in collision with surface
@timid dove

hm

what you say seems to include that

[timid dove]

Yep. It would be like gravity * sin or cosine of the slope angle

Applied as ForceMode.Acceleration in FixedUpdate

[viral ginkgo]

@timid dove I was thinking about that as well
But i was thinking just negating the gravity first

and it worked

I mean i am not countering what remains of gravity after grounds counter force

I am countering the gravity before it can produce a ground counter force

    private void OnCollisionStay(Collision collision)
    {
        rb.AddForce(9.81f * Vector3.up * rb.mass);
    }

[timid dove]

yeah that's fine

I would use rb.AddForce(-Physics.gravity, ForceMode.Acceleration);

but the effect is the same

[viral ginkgo]

👍

[storm wagon]

Don't know if it count's as physics but.
https://gyazo.com/a27bdd72cb1399d5fa81be32062ff03e
I don't want the weapon to collide with the floor on the default layer. What am I doing wrong?

[timid dove]

Do you have any Colliders on the parent object?
What layer is the white ground on?

[storm wagon]

The White layer and the parent are both Default.

white ground*

[timid dove]

And are there Colliders on the parent?

[storm wagon]

Yes.

[timid dove]

The Collider on the parent is probably what's colliding then

[storm wagon]

The collider doesn't look that big.

Actually I just turned the parents collider off but the "Weapon" still stays on the ground.

[timid dove]

Oh I see your problem

You're in physics settings instead of physics 2D settings

[storm wagon]

oh

Thanks so much.

I feel kinda dumb but I just started Unity.

Have a good day/night.

[timid dove]

Night

[mighty sluice]

extreme centipede physics anyone?

https://i.imgur.com/GZ6O0GC.mp4

[regal oar]

Hello!
I am trying to make a simple mechanic where the player is a ball that uses 2D physics to move around, gather speed etc...
The game feel is great so far, but I have a problem : My entire player gameobject is rotating when moving, including its children.
Is there a way to keep this rotation (which is used to move around) but have children with no rotation?
For exemple : what do I do if I want a fixed red square relative to player location instead of this :

(I mean I could place them under another gameobject which follow the player every frame but that seems like a waste of resources)

[ember grail]

Hello everybody! Not sure if this is the right place to ask, if it's not, I apologize! 😅

I am making a sorting system where items are spawning on a conveyor belt and then placed in the box. My problem is that I need to showcase the item placement inside that box. What I need to achieve is 1) check if items intersect/overlap when placed in the box 2) if they fit in the free space, place them. I've managed to get a result using GetComponent<Renderer>().bounds.Intersect but it's not exactly what I am looking for - I need items to be close together. Is there an easy way to check if two cubes overlap inside the scene and, if not, to place them next to each other (or on top of)?

[neon glade]

No scripts changing the behavior. Better look here.

[timid dove]

what components are on it/its children?

[silver geyser]

I have a hard question. What size My Unit, Map, every Object should be compared to real life, how big is Scale 1 in the game compared to real life? Will it lag more or less if My video game (Units, Map, Objects) are 100 times smaller or bigger?

[calm plank]

Up to you really. You get to decide, you just have to be consistent. But, it's common to use 1 unit = 1 Meter

[silver geyser]

Because I always loved using 0,1 as a 1 meter, it did made difference sometimes, not in Unity, I am new so I do not know.

[neon glade]

Transform, Mesh Filter, Materials, Box Collider, Rigidbody

[proud nova]

It does make a difference in a lot of systems as 1 unit = 1 meter is often assumed

The further you deviate from it, the less a lot of settings and behaviour make sense.

I wouldn't do it unless you have a technical reason to do it

[calm plank]

That's also true. You can choose whatever scale you like, but there's really no advantage to going against the grain either.

[edgy aurora]

How can I get the depenetration of a collider with the scene?
I can get it with one other collider with compute penetraiton
but whatabout if the object is colliding with multiple objects at once

[glacial jolt]

@edgy aurora Physics.OverlapX to gather the colliders intersecting, then compute pen to get depend

[edgy aurora]

yea im doing that

but how do I combine the depen of all the colliders

@glacial jolt

lets say the object is colliding with two objects at the same time, how would i get the depen of both colliders

[glacial jolt]

ahh. Don't think Unity has an API for that, I usually just sum them and perform it iteratively

[edgy aurora]

that would be inefficient though

[visual furnace]

Anyone can help me? I'm trying to Isolate time

d = distance from each other
t = time
v01 = Initial Velocity of Object 1
v02 = Initial Velocity of Object 2
a1 = Acceleration of Object 1
a2 = Acceleration of Object 2

v01t + (a1t^2)/2 + v02t + (a2t^2)/2 = d

t + (t^2) + t + (t^2) = 2d / 2v01 + 2v02 + a1 + a2

2t + 2t * 2t = 2d / (2v01 + 2v02 + a1 + a2)

I don't know what do next and I don't know if I've been right so far.

[gentle cape]

As some of you might know I have had a bit of an issue with a trigger acting as a collider ... now in case someone else is or will have the same issue, this might be something you want to do ... I basically added this script to the object that was giving me trouble ... and I have put it on all trigger objects for good measure and it works.

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

public class IgnoreCollisions : MonoBehaviour
{
    private void OnCollisionEnter(Collision collision)
    {
        if(collision.collider.CompareTag("Player") || collision.collider.CompareTag("Enemy"))
        {
            Physics.IgnoreLayerCollision(0, 12);
        }
    }
}

You just put this script on the trigger object(s) and it ignores all layers in the scene (keep in mind that the numbers may vary, as the number of layers vary)
It may seem a bit of a clunky solution , but after a week I am just happy that it works now

[timid dove]

You know you can set up layer-based collisions in Project Settings right?

[hoary scroll]

I currently have a pushable object constrained to the x axis. Is there a simple way to also constrain it such that it can't move past X=x1 and X=x2 that isn't just adding physical stoppers to the "rail" that it's on?

also, for some reason, if I constrain the Y-axis, it stops moving. Why? I don't want it to be able to bounce up in the air either.

[random willow]

I'm having issues with my player controller running up even slightly slanted walls, the behavior looks like this:

and here is some code on a capsule to reproduce it

public class MoveRigidbody : MonoBehaviour {
    void Update() {
        Rigidbody rigidbody = GetComponent<Rigidbody>();
        rigidbody.velocity = Vector3.Lerp(rigidbody.velocity, transform.forward * 10, 0.8f);
        rigidbody.AddForce(Physics.gravity, ForceMode.Acceleration);
    }
}```

here are the rigidbody settings

and friction settings

I know friction is the reason its going up

[timid dove]

are you trying to prevent running up walls or cause it?

[random willow]

prevent

I know its due to the friction settings

but those settings allow the actual controller to behave well

is there a way to modify vertical friction without changing horizontal?

[timid dove]

AddForce in Update is ⛔

unless it's a 1 shot impulse

[timid dove]

nope

[random willow]

oh my bad

its in fixed update

on the actual controller

I just did the test script as a quicky

[timid dove]

Anyway this: rigidbody.velocity = Vector3.Lerp(rigidbody.velocity, transform.forward * 10, 0.8f); basically is going to very easily climb up anything or really jsut fly anywahere the player is looking

[random willow]

ive also swapped over to an addforce

in the main one

[timid dove]

it's going to very quickly set your velocity to transform.forward * 8

[random willow]

sorry the test script is a bit dated

yeah

[timid dove]

ok well - hard to say without seeing your real code

[random willow]

there's the full thing

a lot of it is fluff though, thats why i made the test one

its also not amazing code, im just learning the new input system

[timid dove]

targetVelocity = Vector3.ProjectOnPlane(targetVelocity, groundNormal).normalized * movementSpeed +
                             ((isGrounded && jumpingState == JumpingState.NotJumping) ? Vector3.zero : _transform.up * velocity.y);```

part of the problem is here ^

since you're normalizing your target velocity to the ground normal

that pretty much makes your character glide straight up a slope of any steepness

[random willow]

the thing is, the slope im using is 89 degrees

[timid dove]

And then you do this:

_rb.AddForce((targetVelocity - velocity) * stickiness, ForceMode.VelocityChange);``` which will pretty much instantly accelerate you to that target velocity

[timid dove]

yeah then this code will set your moving at full speed almost straight up ;D

[random willow]

the raycast hits nothing so its not normalizing to the slope

[timid dove]

oh?

[timid dove]

well then it probably just comes down to how fast you're going vs your mass vs the lack of friction

[random willow]

mhm

I suppose I could use OnCollisionStay to calculate vertical friction and apply that?

[timid dove]

worth a try maybe

[random willow]

OnCollisionStay is not linked to the physics cycle right? so no force changes in there

[timid dove]

it is linked with the physics cycle

it runs as part of the physics update

[random willow]

ok

so im good to use AddForce?

[timid dove]

yeah

It will run once every fixedDeltaTime - just like FixedUpdate (as long as the objects are touching)

You can see where it runs here: https://docs.unity3d.com/Manual/ExecutionOrder.html

pretty much at the end of the physics section

[random willow]

does it run on first and last frame as well?

or only enter and exit there

[timid dove]

it runs on every physics update during which the objects are touching, including the first one.

[random willow]

ok

[timid dove]

It won't run on the first update during which they are not touching (when OnCollisionExit runs)

[random willow]

ok good thank you

[random willow]

@timid dove Just a follow up, the OnCollisionStay Idea worked out beautifully. I calculate the impulse applied along the ground normal and counteract that scaled by a factor depending on the angle the wall makes, you could do conditional stuff with the verticalScale as well to make certain slopes climbable I think, here's the code I came up with, thanks again!

private void OnCollisionStay(Collision collision) {
            Vector3 totalImpulse = collision.impulse;
            
            Vector3 averageNormal = Vector3.zero;

            foreach (ContactPoint contact in collision.contacts) {
                averageNormal += contact.normal;
            }

            averageNormal /= collision.contacts.Length;

            float verticalScale = 1 - Vector3.Dot(averageNormal, groundNormal);
            Vector3 impulseOnNormal = Vector3.Project(totalImpulse, groundNormal);

            _rb.AddForce(-impulseOnNormal * verticalScale, ForceMode.Impulse);
}```

[timid dove]

Awesome! Glad you got it working.

[lucid swift]

i cant seem to get my sprite to collide with another object

i have a kinematic rigidbody 2d and a box collider 2d on the sprite and just a box collider on the wall object

i was orignially using a tilemap thinking that mightve been the problem but i switched it to a game object and its the same issue

[stuck bay]

also this is so weird, with RB the position is set so much more often https://i.imgur.com/f22fOsh.gif

stupid question but does rigidbody interpolation update position faster than physics.time step?

[hollow echo]

Yes

That's the point

Although the inspector isn't showing every update anyway, so looking at it to judge that is meaningless

[stuck bay]

i see

[cunning laurel]

So I have a cube that successfully falls under gravity until it hits the floor. The problem is that I have added some code to move it around with my mouse which can allow the cube to go through the ground. Is there a way to prevent this with physics?

Or do I need to hard-code something into when it reaches a certain height?

[timid dove]

you need to move your cube in a physics-compatible way

either via rigidbody methods or with a CharacterController

[stuck bay]

is collision detection setting in rigidbody working for raycasts too?

[timid dove]

raycasts don't know anything about rigidbodies

only colliders

[cunning laurel]

@timid dove Thanks for clearing that up its makes a lot more sense now! Its only a cube around the screen so I'll look into the rigidbody suggestion and see if I can alter my move code.

Out of curiosity If I forget about using gravity is there another way to prevent my cube going through the floor when being dragged by the mouse if I don't use a rigidbody?

[timid dove]

Use a charactercontroller or do your own raycasting/boxcasting/spherecasting or whatever to detect if there are obstacles in your cube's way

[cunning laurel]

Thanks @timid dove I'll need to read up on the Character Controller I always thought of it being used more for actual characters in a game but it makes sense that they can also be used for actual game elements. I appreciate the advice 🙂

[timid dove]

I'm using one for my camera in my current project 😄

it's convenient

[cunning laurel]

@timid dove oh that sounds interesting! Is it going to be a first person game?

Make a lot of sense now that I think about it!

[timid dove]

nope, top down 3D factory building game

[cunning laurel]

Thats cool! Whats the advantage of having a Character Controller on the camera in that case?

[timid dove]

It collides with my terrain and other objects so that the otherwise free-flying camera doesn't pass through stuff

also automatically goes up slopes etc

[cunning laurel]

Seems like a really creative solution! And like a fun game too 🙂 Building games are always a lot of fun

[proud nova]

There should be a gizmo that resizes as you change those values

[lucid swift]

ok ive asked so many people and ive yet to get a response so i might as well try here again, but i cant get my character sprite to collide with a wall sprite

im moving the character sprite with transform.position

and im using a kinematic rigidbody 2d and box collider 2d on the player character and a box collider 2d on the wall sprite

I have this code right here to detect the collision but the trigger isnt even procced

void OnTriggerEnter(Collider other) {
    Debug.Log("Collision");
    if(other.gameObject.CompareTag("Border")) {
        Debug.Log("Top Border");
        moveDirection = Vector3.zero;
    }
}```

[timid dove]

You're using the 3d version

you need OnTriggerEnter2D(Collider2D other)

[lucid swift]

omg of course its that simple

thanks

[timid dove]

OnCollisionStay takes a parameter

see the example here: https://docs.unity3d.com/ScriptReference/MonoBehaviour.OnCollisionStay.html

Also you shouldn't multiply your impulse jump force by Time.deltaTime

That will result in different jump heights depending on your framerate

[timid dove]

Ok well aside from that first thing to check is - Is OnCollisionStay running at all?

If it's not running check:

• Do both objects have 3D colliders
• Does at least one of them have a 3D Rigidbody?
• Are both of them not triggers?

[timid dove]

what layers are they on

And that layer is set to collide with itself in physics settings?

[timid dove]

idk - everything sounds like it's set up correctly from my distant vantage point

But maybe there's something glaringly obvious if I were actually looking at your project/code

[mighty sluice]

anyone know what the cleanest/cheapest way to apply a unique gravity force to all rigidbodies in a scene?

for example, let's say i want to make a center of gravity for a toy planetoid

I realize i can zero out the gravity force, get a script that references all rigidbodies, and iterate through them to calculate a relative down, and apply a force, but that seems so inelegant if i want to have 1000's of rigidbodies

i can also use the jobs system for calculating the downs, but still the AddForce().... that's my worry

[timid dove]

There's not really any other way to do it than iterating over all of them.

[mighty sluice]

not sure if unity's physX gravity uses solver iterations or not

[timid dove]

Not if you're using Rigidbody at least

[mighty sluice]

i suppose it's the only way...

[timid dove]

What's your worry? Just the performance?

[mighty sluice]

yea im always concerned about scability due to the nature of the environments

[timid dove]

I mean with 1000s of rigidbodies you may need to use ECS

[mighty sluice]

eventually it's a must, assuming i can get functional joitns working as well as configurable joints

[timid dove]

NOw - depending on what you actually want to do with these things

you might be able to get away with a compute shader

like if they're just visual

[mighty sluice]

unfortunately i want more than just visual

i need the learning agents to have quasi realistic experiences with physics

[timid dove]

With the numbers you're talking about, this might be an ECS job

[mighty sluice]

compute shaders for fluid and atmospherics simulations (even pulling flow forces out of it for custom aerodynamics stuff) is on the docket

yea i have used jobs for that purpose before

https://i.imgur.com/zKmt9MP.mp4

for example, these lamprey are 8 rigidbodies and joints a piece, and they have a jobs system running calculations every fixed update to calculate drag forces

which are then applied in local monos

[timid dove]

looks good

[mighty sluice]

physics makes it look good, but also the realism of the lamprey nervous system 🙂

scaling beyond this is kinda tough without ECS physics

im kinda afraid to attack it to make the switch, but i know its necessary for scaling

[ember grail]

what is the easiest way to detect overlapping when placing items?

[wide nebula]

Use https://docs.unity3d.com/ScriptReference/Physics.CheckSphere.html

[ember grail]

CheckBox would be equvalent for cubes?

[wide nebula]

Yep

[stuck bay]

why is that i experience more shaking when two interacting objects have interpolation turned on?

is that normal?

i get best results with interpolating planet, and not interpolating player

i also wonder if i wont need the interpolation on player in other cases than planet-based movement and gravity

[timid umbra]

Hi, I tried to subclass a BoxCollider to add my own field to it but it seems I cannot AddComponent<X>() it. Is there any other way to do that?

[timid dove]

You won't be able to subclass BoxCollider successfully

The problem is that it's just a wrapper around a native C++ object

There's probably more to it than that but for whatever reason it's not possible

[supple sparrow]

@timid umbra then you could use Composition instead of Inheritance

[timid umbra]

I would normally do that but I am modding a Unity game that has no support for physics and I am implementing a flamethrower and need lots and lots of boxcollider. Since I don’t have the control I normally would like to have, I need to create a GameObject for let’s say every 400 colliders and attach one collision script on it. I would though know which game object a particular collider is for. It’s kind of an unusual situation.

I solved it for now by creating an subclass of a PhysicsMaterial that holds the reference I need. Kind of hacky

[timid umbra]

Hmm, that doesn’t work (I suspected that already)

[timid dove]

I'm confused - if you have a collision script - this.gameObject is the gameobject that the collider is "for", no?

[timid umbra]

No, as I wrote I create such a game object only to hold all the box colliders

The game I mod does not use game objects

So I need to create them myself but the game has too many pawns that I cannot simply create a game object per pawn

It is pretty hard to create a paging system for this so I tried to cheat

[timid dove]

You said this:

I would though know which game object a particular collider is for

[timid umbra]

Sorry unclear. Their game object, not GameObject

[timid dove]

I'm teying to figure out exactly what data you're trying to get

so you have a GameObject with a bunch of BoxCollider components on it?

like 400 of them?

[timid umbra]

Yes

[timid dove]

and you have a script on that GO

with... OnCollisionEnter on it?

[timid umbra]

Yes

[timid dove]

and you're trying to figure out what exactly?

[timid umbra]

So all I want is a correlation between each collider and some other object

[timid dove]

which one of your colliders was involved in the collision?

So can you just put a Dictionary in your script with that correlation?

Dictionary<Collider, SomethingElse> colliderMappings;```

[timid umbra]

Probably. I want to find out if I can do it more directly

[timid dove]

How do you define the correlation? Do you want to define it in the editor?

or at runtime in a script

[timid umbra]

All modding is at runtime

[timid dove]

If they're all on the same GameObject I think the best you can do is keep the correlations in a structure like that dictionary. There's not going to be a way to add a "note" or something to the Collider component without them being their own separate GameObjects

[timid umbra]

Alright. Good to know

Thanks

Do you think that creating a 1:400 go:boxcollider structure is better than 400 go+boxcollider?

Performance wise

I only need to detect collisions to remap their coordinates back to foreign game objects and continue the logic there

[timid dove]

I don't think there will be any noticeable performance difference. There might be a memory difference but that might be counterbalanced by the auxiliary structures you will need to maintain your collider -> gameobject mappings

I believe that the representation of your scene in the physics engine will ultimately be the same

as it's not aware of GameObjects

there may be a difference if it's 1 rigidbody vs many rigidbodies

[timid umbra]

Good to know too. Thanks

So my next approach is to maintain one GO per pawn in the game and have it reference it. All GO will have the same collision script and one boxcollider/capsule collider per GO. Since the game can have 2000 pawns easily I might need to only use them for pawns that are in the shooting radius of the pawns with the flamethrower. So my limits will either be the number of GO or the allocation of them. Later can be done with a pool I guess, making all this a lot more complicated. Oh well

[neon glade]

Here I show the contact points, normal and resultant impulse

[neon glade]

You can see that all 4 corners are in contact at OnCollisionEnter. This creates a resultant impulse with no torque.

[neon glade]

even worse

[random knot]

Anyone know here how to get accurate skin mesh collider?

[buoyant aurora]

You can activate the convex on the mesh collider component

If you don't need physics with the object, mesh collider is the best you'll get. If you do need physics, use the convex. If you're not happy with that, then you're gonna have to make a custom shape with all the other colliders combined. (Box Collider, Capsule Collider, etc...)

[dusky prism]

Hey guys,
Why it is good to not use Rigidbody2D when creating custom 2D character controller ?

[frigid pier]

You would be using it anyway if you want to receive events. It's just a different design you need to decide if you are going to use physics, it will need additional tweaks and handling of physics system or purely kinematic mode handling physics yourself

[dusky prism]

I mean if I add Rigidbody2D to my object and activate its Kinematic mode then I don't have to find overlaps between colliders.
But why some people prefer not using Rigidbody2D and find all overlaps and resolutions against using Rigidbody2D in Kinematic mode ?

@frigid pier

[stuck bay]

my player is getting swept cus planet velocity is too high.
is there a way to add velocity to player (but not to velocity property, to MovePosition)?
i tries this

playerRigidbody.MovePosition(planetHit.point + galaxyRigidbody.velocity.normalized);

velocity is world, not local, but i dont see how i could transform it

[neon glade]

Any idea what is going on here?

The width of the collider surface dramatically changes the behavior of a rotated cube dropped onto it

Dropping a unit cube rigidbody rotated 22.5 degrees onto a 1,0.1,1 cube collider works as expected

Changing the scale of the floor (cube) to 2,0.1,2 breaks it

it bounces straight up instead of tumbling as expected

[neon glade]

Slow mo

[noble notch]

I'm trying to make a bicycle vehicle for my game, but I've noticed the bicycle can't go up pretty much any incline

what setting(s?) do I change in the wheels to fix this?

[neon glade]

Are the wheels expected to apply force to the incline?

If so, maybe friction?

I added debug rays. You can see that there are only 2 contact points when the floor is 1x1 but there are 4 when its 2x2. Why might this happen?

ah its tunneling. Smaller fixedTimeStep?

[noble notch]

I don't know. They're wheel colliders.

All the friction settings seem to have weird negative side effects

I also have no clue what any of this means.

[neon glade]

Ah sorry I’m not that familiar with wheel colliders. Probably good to learn about all of those values if you’re going to use wheel colliders.

[wraith quartz]

https://youtu.be/H3_Nc-SDTMo

why does it just ignore the collider

[stuck bay]

my cube falls down the map https://gfycat.com/blaringneararchaeocete

[hollow echo]

Check that the layers collide with each other in the Physics settings

[stuck bay]

where would that be?

[outer furnace]

Edit -> Project Settings -> Physics

Another thing to check, is to make sure the dice collider doesn't have "Is Trigger" selected

Triggers won't collide with anything, so it's gotta be unchecked

[outer furnace]

Check the size of the box collider on your plane.

Might need to increase it in regards to the y axis

[daring bronze]

@outer furnace can't he remove that since he has a mesh collider? I think it's the one I told him to add which is no longer relevant because collider wasn't the issue?

[daring bronze]

since he already has a mesh collider

[outer furnace]

Oh. I completely glanced past the mesh collider. Seems kinda pointless to have a mesh colider on a rectangle though lol

[daring bronze]

yeah that's what I thought but seems Unity's default for planes

which is why I suggested a box

[hollow echo]

I would check things out in the scene view and ensure everything appears to have their collider in the right place...

I think that maybe your dice's collider might not be where you think it is?

[hollow echo]

I can't think of anything else

you can test this with a default plane and default cube with a rigidbody on it and they collide

or at least, they do by default

[stuck bay]

here is a new one

[daring bronze]

That's probably the case as his dice bounces but the mesh falls through the plane first

[stuck bay]

it stopped bouncing

[daring bronze]

your new solution in the above image stopped bouncing?

[stuck bay]

the one before

https://gfycat.com/blaringneararchaeocete

[outer furnace]

gotta reassign the physics material if you made a new cube

[daring bronze]

I'm guessing you changed something that no longer applies the physics to the cube, but regardless in your new solution do as Zaffre stated and apply the physics material to the new cube

If vertx was right in assuming the box collider was positioned outside of the mesh, then the new cube will have a box collider scaled by default to the mesh

[hollow echo]

Preferably use a paste site like - https://paste.ofcode.org/

• https://hatebin.com/
• https://paste.myst.rs/
• https://hastepaste.com
• http://pastie.org/

[stuck bay]

https://pastebin.com/RxELpLXT https://pastebin.com/RYT460AW https://pastebin.com/gJYvBnyw

[hollow echo]

yeah none of these are relevant

[daring bronze]

I would do as vertx & zaffre stated. Create a new plane & cube, then apply the components you need such as the Physics Material (bounce) & scripts you've written. Then test whether it works, even if it doesn't at least then you've ruled out it being a simple collision issue.

[hollow echo]

unless you're pressing space, which, you aren't

[daring bronze]

It's highly likely it was a collision issue because in the first gif/clip you sent the cube bounced, which suggests it collided with something as I assume it would only bounce if it were to collide? and so on that basis it's likely the collider was positioned outside of the mesh

[outer furnace]

Wait- which gif/clip did it bounce? I thought all gifs showed it phasing through the plane entirely?

[hollow echo]

I've not seen it bounce either

[stuck bay]

https://gfycat.com/unevenrawastrangiacoral

[hollow echo]

That looks like an offset collider then

#⚛️┃physics message

[outer furnace]

Might just be an issue with the Side1,side2,side3,yaddayaddayadda, not being zero'd out on the transform, maybe?

[stuck bay]

now it does not fall after i remade them https://gfycat.com/femininedisguisedfallowdeer

https://gfycat.com/singleminiatureindianskimmer

[outer furnace]

@stuck bay Take a look at the compiler, it's throwing you an error because you didn't put the rigidbody component on the dice object

[mighty sluice]

Is there anyway to get a reading of the friction being applied on a collider or given contact point?

[stuck bay]

now it just falls https://gfycat.com/mistyinfatuatedblobfish

[proud nova]

@mighty sluice Since 2021.2.0a12, there is a new contact modification event that might enable that.
https://forum.unity.com/threads/experimental-contacts-modification-api.924809/

[wide nebula]

Your collider is a trigger, which will pass through other colliders.

[stuck bay]

then what should i do?

[wide nebula]

Not make it a trigger?

[stuck bay]

now it does not bounce like a normal dice

[wide nebula]

Give it physics material with increase bounce.

You also need to add force to it like you're throwing it. If you just drop a dice a few cm's off the surface of a table, it's not going to "roll".

[woeful bluff]

I have a tree with this and a mesh renderer in the inspector, but when the game starts it doesn't fall

[wicked phoenix]

What's the most precise way to move Rigidbodies? Addforce or velocity?

[timid dove]

they're the same thing

AddForce simply changes the velocity

the most "precise" way would probably be MovePosition since that will set the position of the RB to an exact position you give it

it won't necessarily be realistic though

[wicked phoenix]

Thanks. I'm trying to figure out the best way to have a rigidbody object follow its navmesh agent instead of the agent controlling the movement. That way I can apply forces to the object

Would you recommend Moveposition or Addforce in that case? @timid dove

[timid dove]

If you want to apply forces to it you will have to use AddForce

But you'll need to basically write a PID controller

to get it to follow nicely

[wicked phoenix]

What's a PID controller?

[stuck bay]

@wicked phoenix http://luminaryapps.com/blog/use-a-pid-loop-to-control-unity-game-objects/

[long storm]

Hi guys!
I was trying to make a rope that connects 2 masses together, found this tutorial:
https://www.youtube.com/watch?v=XvS4U5Y0d4g
And it works great, except for when the swinging object's inertia is to high it does this:

anyone knows how could i stop it from ignoring the collision like that and just stop when it hits the collider?

[stuck bay]

this is my bounciness

should it be higher ?

[wide nebula]

It should be as high as you need it to be to match your game feel.

[stuck bay]

the max bounce you can have is 1

[wide nebula]

Yep, it's a normalized value.

[stuck bay]

should bounce more

[wide nebula]

Throw it with more force then. Also try changing the Bounce Combine to maximum.

[stuck bay]

now it only bounces to 3

[wide nebula]

This is getting tiresome. Add some torque and stronger force to the throw. Have you ever used real dice before?

You can't just rely on gravity to make it work, you need to mimic the force for someone actually throwing it onto the table.

[hoary sparrow]

How to get the value of 'x' from cubic equation ax^(3) + bx^(2) + cx = d where a,b,c,d are variables?

[neon glade]

Im working on dice as well and having some issues

What's helped:

• Decreasing Fixed Timestep by 1/2
• Using large dice (1x1x1)

The issues appeared to be from tunneling. Both of these helped.

[stark crystal]

hey I have a problem, a block keeps on falling through another which is supposed to be a solid object which doesn't let anything fall through

(game view)

code for the block that falls through: ```cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class up : MonoBehaviour
{
public Rigidbody Cube;

// Start is called before the first frame update
void Start()
{
    
}

// Update is called once per frame
void Update()
{
    if (Input.GetKey("w")) {
        Cube.AddForce(0, 10, 0);
    }
}

}

[timid dove]

Do your objects both have Colliders?

Is either Collider a trigger?

[stark crystal]

Where could I find that?

[timid dove]

Collider is a separate component you add to the object

[broken ivy]

I am currently having issues with the configurable joint component on the move-able platforms hidden in the wall. Does anyone have experience with this?

[green juniper]

Hi, I have a problem, I am new, so, this could be a begginer's mistake, my 2d hinge joints attach to nothing , I am trying to build a ragdoll, but the hinges do not attach like in the video

Can somebody help me?

Forget it

I figured it out

[proud escarp]

This is only a showcase, but i finally made a balancing ragdoll in unity 3D, I might Upload a tutorial on youtube

The only problem is that his foot get inside the ground i will fix it now

[buoyant aurora]

Looks good! Does it work with IK as well?

[wicked furnace]

Hi! I'm having a weird physics issue with a 2D toy project. I have a ball with the Y position frozen in constraints. If I run the project and remove the constraint in the inspector, the ball falls as expected. But if I programmatically remove all constraints while the project is running, like so:

public void Drop(InputAction.CallbackContext context)
    {
        if (state == BallState.PreDrop) #initial state
        {
            state = BallState.Dropping;
            GetComponent<Rigidbody2D>().constraints = RigidbodyConstraints2D.None;
        }
    }

I can see the constraints getting removed in the inspector, but the ball doesn't fall. Is there something else I need to do?

[supple sparrow]

What is the sleeping mode in the rigidbody ?

[wicked furnace]

Start Awake.

[supple sparrow]

maybe try

Rigidbody2D rb = GetComponent<Rigidbody2D>();
rb.constraints = RigidbodyConstraints2D.None;
rb.WakeUp();

just to try to slap him out of his nap 😛

[wicked furnace]

That worked. Thanks!

[supple sparrow]

Awesome, happy coding 👍

[autumn dune]

When you're adding force like so, will the object continue to move even without the keys being pressed? or do i have to code in friction myself

continue to move as in not decelerate

[timid dove]

Rigidbodies will be slowed by:

• If they have drag set > 0
• If they contact other colliders, they will be affected by friction according to the PhysicsMaterial2D of the colliders involved (the default material has friction)
• If they collide with other colliders, there will be impact forces
• Any forces you add opposite the velocity.
• Any direct changes you make to their velocity.

Otherwise they follow Newton's first law of motion @autumn dune

[autumn dune]

Thank you!

[little dew]

Is there any way to prevent a third person camera from clipping through walls? It works kind of. I use Cinemachine and it follows my character and collides with walls, doesnt do it perfectly and goes through them some of the time. All objects have colliders.

To be more precise I am in a precise it briefly clips through the walls while I move around the view with my mouse and then lowers the distance so it stay inside the room.

[little dew]

Nvm Dampening when occluded in Cinemachine had to be 0 for that to work.

[visual furnace]

Hi Guys, I don't know what is wrong, I've been trying to figure this out for over a week now,
I am getting, 99~% accuracy of expected result,
ex. if Expected result is 100, I'll sometimes get 100.000156, something like that, Mostly happen when 1 of the Object has 0 Acceleration

those double values were float before, I thought that would help. I'm not sure If there's a problem on the Formula, or somewhere else

[timid dove]

That's about the best you can expect. There's always going to be some degree of error when doing floating point math. You need to work around it.

[visual furnace]

Thanks Man, can finally move on to other things.

[stuck bay]

i have rigidbody shaking problem

not in editor but in build

[stuck bay]

OH FIXED LOL

i had to increase physics time step to 60fps per second

but im curious now cause i limit game to 60fps, but thats cus VSYNC (monitor refresh rate) is 60 for most monitors and my current monitor

maybe people with 120refresh rate monitors

will get shaking??

i have no way to check that

but if yes then i will have hard time...

not only setting physics to 120fps would use lot of cpu but also wont work for me as i need every players fixed update to run with same frequency

[iron wing]

Is there anyway I can achieve that with raycasts? I want the "layer" to be set to ground for the top, and to default for the sides

I use the layer "ground" for the tilemap and check for walls this way, so I can't make the left and right raycasts check differently

[green valley]

Three gameobjects

Three colliders

all children of the main box

the top one being a box collider

marked ground

well actually all you need is two colliders

Like this

You'd want to make it much thinner, but you get the point

[iron wing]

The left and right raycasts would detect the top one and think a wall is there
Already tried that solution :/
(But thanks :p)

[green valley]

Sorry I didn't get back to you, I have this channel muted. Did you try using a edge collider 2d?

[proud nova]

@iron wing Checking the normal of the raycast would probably do

[iron wing]

The normal?

[timid grove]

so i applied ragdoll physics to my enemy.. but after i turn on ragdoll.. the enemy teleports to spawn position.. how do i stop this from happening?

[last steeple]

Sup!
Trying to set up some efficient collision detection in a 2D project in a scenario like a bullet hell shooter, so 100 objects or so against one or two other objects.
The naive implementation would be sprites with circle colliders and continuous detection, but perhaps there are cleverer ways or ideas on how to achieve this.

[minor yew]

I have this very weird case, where the RigidBody2D won't accurately stops when collided with others.. sometimes it stop perfectly sometimes it doesn't.. Already set Collition Detections = Continuous + Sleeping Mode = Never Sleep... still not working

any idea?

[minor yew]

apparently, as I was using leantween to move those objects, it messes up the timing when the collision was set to a very tight space.. adding delays fixed it

[sage wolf]

Is there soft body physics in Unity or would i have to implement it myself ? (Buying something like dynamic bones is not an option)

[timid dove]

There's nothing built in. Make it yourself or buy an asset

[summer saddle]

Guys, is there any way to disable a rigidbody to enable it again later? setting it as kinematic removes all its velocity so it doesn't work

[stuck bay]

does raycast count as physics?

[timid dove]

Yes

It's a query into the physics engine

[timid dove]

Save the velocity in a variable and restore it later

[summer saddle]

Is that the only thing i should save?

[timid dove]

if that's the only thing you care about restoring.

maybe angularVelocity too?

[summer saddle]

i care about restoring anything needed to resume the simulation

without losing the state

[timid dove]

that would be:

rb.rotation;
rb.position;
rb.velocity;
rb.angularVelocity;

[summer saddle]

alright ty

[dreamy pollen]

Is there a reason my object would be "catching" on the square in this scenario?

[timid dove]

because... they're colliding?

[dreamy pollen]

Sphere does not have gravity applied, but is also not kinematic, I am manually managing velocities

[foggy rapids]

you have locked rotation?

[timid dove]

friction is a thing

[dreamy pollen]

Yes

Physic Material is zeroed out on friction, set to minimum

[timid dove]

well it's still trying to pass straight through the rectangle right?

and bounce is set to 0

so you won't get much of a rightward force

or maybe none at all

[dreamy pollen]

Right, I suppose I need a solution to apply rightward force

[timid dove]

you are expecting what behavior?

A slide?

[dreamy pollen]

yes

[timid dove]

and drop

[dreamy pollen]

correct

[timid dove]

Yeah I think maybe bounce being 0 might mean there's no rightward force happening?
idk

[dreamy pollen]

I'll try playing with that value

[foggy rapids]

what's actually happening?

[dreamy pollen]

You know, I think setting bounciness to 1 alleviated my problem.

Hrmm, I wonder what would be a good way to push it rightward procedurally. Trying to think of what the Vector math would look like. Something something OnCollisionStay

(instead of bouncing it)

[civic field]

Do they just jitter non stop even when nothing's happening ?

So when does it happen ?

[civic field]

Do you addforce every fixedupdate once the specific time is reached ?

@raw yarrow

is it not that the direction changes every frame so it looks like jitter

@raw yarrow

[wary ferry]

Does a character controller require a rigidbody? It keeps automatically adding one

[silver swan]

Trying to make a vehicle with 4 wheel colliders, but it can't just move straight forward and always steers to the side by itself. Is it some kind of physX bug or what?

[civic field]

No problem lol

[silver swan]

Tried to change sideways friction on wheels, but doesn't really help

[timid dove]

Are you talking about the default Unity CharacterController or some custom script

The Unity one doesn't require one

[timid dove]

Is your model lined up in the right direction?

[wary ferry]

The default unity one, I figured out that it's adding it because apparently my player controller script needs it, but it only ever references the CharacterController and not a RigidBody

[silver swan]

Yes it is, and wheels are on perfect range

[loud drift]

anyone - is it possibly to use unity subsystem physics job to bake a custom collider at runtime without writing a whole subsystem?

need it to be baked on the side thread

[wet crow]

I think that We can now change dimensions using speed now

[celest blaze]

My object falls really slowly, I tried increasing the objects gravity scale but that doesn't really change it as much as change the heigh that it starts to fall when jumping.

Could that be because my object's transform scale size is set to 12?

[timid dove]

Larger objects appear to fall more slowly than small objects due to the relative scales and distances involved. It's an illusion though.

It's also possible that your movement script is causing the object to fall more slowly than it normally should

[noble turtle]

Would anyone know how to rotate a wheel collider to face the target? Its for auto driving following a node system

[warped skiff]

im writing some physics related code, and was wondering if there was a simply way to run my game @ a fraction of the speed to allow the physics more processing time during debugging?

[rustic pagoda]

Is there a way to use Rigidbody physics to move an enemy with NavMeshAgent

[hasty kiln]

may I ask a angular movement problem here? not strictly related to physX engine.

[timid dove]

This channel is about Physics in general, not just PhysX

(btw Unity supports two other physics engines besides PhysX)

[hasty kiln]

ty, here we go
I have two points, starting point A and destination point B
I have a object that rotate at a fixed "max angle" α (is always turning direction)
this object have a constant velocity V to forward, describing a parabola,
there is no gravity, drag etc

I have α, I need to find a V that the object trajectory cut the given point B, or in the other way I can provide a V and check if the point B is inside or outside of the theoretical circle that describe the moving object

so with the α fixed, I only can "enlarge" or "reduce" the circle that it describes using V

most of the examples that I have read have a invisible center of the circle trayectory, given by default, but Idk how to get this point in this case

[hasty kiln]

update: it is possible to get it just using trigonometry, just have to use that the tree points (a b and the teorethical center r) conform a Isosceles triangle, dividing it by two you get two right triangles to use
and with the property that all angles form 180 degrees you can get the internal angles from 90 - alpha, and from the angle between the starting forward direction and the point (we can call it beta ) so is (90 - beta)
the final formula (simplified to fast calculus) is

(1/Cos(90-beta))* ((A-B).magnitude/2) / (1/Cos(90 - alpha)) = Velocity

[hasty kiln]

I know it is, a non-elegant way to do this, and wont work on negative numbers, because the "beta" angle is inverted, but, with a small conversion works fair ok in practice.

[deft nymph]

ive got a bit of an issue
im using projectiles for my shooting, and my room is made using that probuilder feature where you can turn a room inside out

problem is, the bullets destroy when theyve hit something (in OnCollisionEnter). but for some reason, this is called when they are instantiated, so they disappear instantly
how can i fix this?

its even weirder, because if i drop one of these bullets in before playing, it works fine!

its only when i instantiate them from the gun that it breaks!

[timid dove]

Why don't you print the name of the thing that your bullet is colliding with in OnCollisionEnter

it could be your gun for example

[deft nymph]

i did

[timid dove]

and?

[deft nymph]

it's the room its colliding with

[timid dove]

ok yeah then this "inside out room" thing probably isn't going to work too well

[deft nymph]

well ive looked at other channels and that's how they go about modelling interiors

[timid dove]

who is "they"

also what kind of colliders are you using

[deft nymph]

Dani followed this method for his game, which uses projectiles and works fine

[timid dove]

you might need to do the colliders separately

[deft nymph]

"they" are yt tutorials

yeah i would but that seems a bit tedious

[timid dove]

and do they ever talk about colliders?

[deft nymph]

well no, but i assumed its fine for interiors

[timid dove]

you are finding now that that assumption might be faulty

[deft nymph]

yeah

in that case i dont know how to go about making my environment since thats how it was all shown

[supple sparrow]

Are you sure it's instantiated where you expect it to be ?

[mighty sluice]

is anyone familliar with the contact modification system that was recently released?

im having a slightly hard time figuring out what's what, given the absence of detailed documentation

in the experimental thread about it, "ModifiableContactPair" is the name of the newly exposed class, but the closest i can find is "ModifiableContactPoint" in my unity version, by using Unity.Physics; (which also creates ambiguity issues)

which doesn't seem to expose the same funcs as the "pair" version

im using 2020.2.2f1, so it ought to be available...

oh im so dumb...

2021 != 2020

[ruby orchid]

I'm new to Unity but used to programming. I am using a capsule collider on my character but when their feet come into contact with a ledge, they sometimes get stuck in their falling animation. Does anyone how to stop this?

[weary moon]

depends on what the parameters are that put you in the falling animation

[calm plank]

The capsule could be stuck on the ledge while technically the feet aren't grounded too (nothing under them) so depending on how you're detecting the grounded state that could explain the animation.

[crisp sable]

could try switching to a convex mesh collider on the pieces, it's probably still using a big ol box collider

[cold rivet]

https://gyazo.com/10caf511cc4f712b9e054743af9762fe

for some reason, the sawblade will not keep its force

the top print prints (-2.1, 4.6), while the bottom print prints (0.0, 0.0)

[native yacht]

Hello, All Wheel Coliders are Same, But one, Front Left is in ground

[stuck bay]

Good evening

I'm following the unity TANKS! tutorial and I'm having a problem with the particle effect they add

https://youtu.be/noXtT_zN-84?t=961

It's timestamped

I've noticed that some people in the comments had a similar problem

I've tried to do what they suggest, but I can't find this setting anywhere to change my particle distance from rigidbody to transform

The unity documentation also shows a very different menu from what I have so I guess it's outdated.

Please @stuck bay if you can help me, thank you 🙂

This is my code btw

https://paste.ofcode.org/UQPHQg3xkc9bcNpLhVwvBf

[stuck bay]

Problem solved, found the solution in the debug menu.

[dapper lichen]

Is the amount of soil that can be suspended in flowing water proportional to:
V^2 (KeneticEnergy)
V (Momentum)
Sqrt(V) (Idunno)
(where V is the speed at which the water flows)?

[sacred forum]

Hello I'm trying to make a basic door with the Unity 2D hinge joints but it's doing this

The yellow circle is my player when I try to walk through the door

any help appreciated

[foggy rapids]

i think you need to connect it to a static rigidbody (the wall)

[sacred forum]

[stuck bay]

So i have an issue where I am using a rigidbody on an enemy character, and the capsule collider for handling collisions with objects is on the parent transform. But I also have all the colliders attached to the bones of the character for the ragdoll system. This means that upon attempting to play, the character just starts spinning and flying 😆 in what i assume is interference between the collideres

any fixes?

[timid dove]

Use the layer-0based collision matrix to make the capsule collider not collide with the ragdoll colliders

or just don't have then enabled at the same time

[stuck bay]

ah ok

I had guessed that the layer system would help

@timid dove Its worth mentioning that the colliders on the bones themselves dont seem to interact with anything until the rigidbody is no longer kinematic

is there a reason for that?

[foggy rapids]

i thought that was the whole point of isKinematic. to switch between acting as bones and acting as physical objects

[timid dove]

Kinematic rigidbodies aren't affected by collisions or forces

other than firing messages to your scripts

[stuck bay]

ah that makes sense

I wanted to preserve the colliders but not have the ragdoll active

But there doesnt seem to be a way to just disable the rigidbodies

oh found a solution

[carmine robin]

What recommendations can people point me to for a replacement to Rigidbody.AddExplosionForce when working with 2D Rigidbodies

One solution was to use 3D rigidbodies and colliders in 2D space and go from there, and if that's the simplest solution, I can easily work with that but I was wondering if anyone had input. Google results were mixed and a bit dated.

[viral ginkgo]

@carmine robin
1 - (distance/explosionRadius)

You could scale your force with this for every object that falls inside the explosion range

[proud nova]

@lapis root No off-topic embeds please

[flint slate]

Hi all! I'm currently working on a VR hockey game, and I'd like to add a flex/bend ability to the hockey stick. Ideally it would flex/bend when shooting the puck or placing weight on the stick. The stick is colliding with the ice, so there's no issue there, but I'm wondering if I would use a certain joint or multiple joints to achieve this. I watched the How to Make a Bendable Fishing rod youtube video already, and I'm still confused. I'm a beginner with Unity and coding, so any help would be appreciated. Please let me know what other info you need. Thanks!

https://tenor.com/view/shoot-player-flex-hockey-ice-hockey-stick-gif-15641459

[bleak umbra]

if this is supposed to be realistic or a core game mechanic, i'd suspect you have to create a custom simulation for that... if its only for visuals you're probably best served with faking it somehow (spline deformer maybe)... if you're after a "goofy" behaviour you can probably chain a few hinge constrains, a spring and some friction colliders together. rigid-bodies (as the name implies) aren't meant to simulate flex/snap... they can only bounce around

[flint slate]

I would like it to be as realistic as possible. Hoping that the flex would work in a real world sense where it affects the speed of puck when shooting. However, I might switch to making it just a visual considering the difficulty of making it realistic. Not a huge mechanic to have in the game, but it would be a nice touch.

[bleak umbra]

custom simulation would be my approach. i.e. use the stick movement/position driven by touch controllers to drive some sort of slingshot/catapult/spring (in code) that fires when the release condition is met.

you probably want to compensate for sloppy user input, and that is best done in code.

[flint slate]

Awesome, I'll start looking into a custom simulation. I'm probably going to have more questions as I develop this game since I'm brand new to this stuff. Thank you for pointing me in the right direction!

[bleak umbra]

btw. just so there is no missunderstanding... custom simulaton utilizing and on top of unity builtin physics primitives (colliders, raycasts, ...).... not "from scratch" 😉

[flint slate]

Cool, thank you for expanding on that.

[subtle elm]

Hey guys, so I though OnTriggerStay would pick up every object within their bounds every frame?

but apparently that's a lie

[bleak umbra]

only other enabled trigger colliders on matching layers

[subtle elm]

do you mean matching layers set or matching in the collision matrix?

[bleak umbra]

yes, matrix interaction

[subtle elm]

yeah thats all fine

it just picks up on 1 object per frame

but not all of the colliders...

[bleak umbra]

are the triggers nested?

i.e. parented to each other

[subtle elm]

Yeah but they're not triggers, they're colliders...

[bleak umbra]

the trigger callback doesnt pick up colliders

you have to use OnCollisionStay

[subtle elm]

srsly? on a collider set to trigger?

[bleak umbra]

no

[proud nova]

@subtle elm You sure? How can you tell it's only triggering once per frame?

[bleak umbra]

if the triggers are triggers, use the trigger callback, but on non-trigger colliders, use collision stay

[subtle elm]

cause I'm using List.Add in the OnTriggerStay and it's not filling it up

I'm also clearing it at the end

[bleak umbra]

are both(all) colliders triggers?

[subtle elm]

I have a bunch of characters with box/sphere/capsule colliders

and one other collider that needs to pick their limbs up

set to trigger

and I need to use an OnStay

[bleak umbra]

are all of them triggers?

[subtle elm]

no the ones on the characters are collision colliders

[bleak umbra]

then thats why

[subtle elm]

yeah but i cant change those to trigger

[bleak umbra]

you can add another collider of the same size and make it a trigger

[subtle elm]

I could do that yeah...

there goes my budget 😂

it's probably fine

so this way i will get a populated array in a single frame?

[bleak umbra]

triggers luckily don't simulate physics interaction

[subtle elm]

just by doing List.Add btw

[subtle elm]

uhu

[bleak umbra]

i'd expect yes

[subtle elm]

Alright cool I'll try it and come back

[lapis root]

???

[proud nova]

Random gifs, for example

[bleak umbra]

mind that collisions are evaluated after Update, means you generally get last frame's collisions... if thats important,

[lapis root]

what are you talking about?

[proud nova]

About the gif you posted earlier

[lapis root]

When? I think I haven't talked here in 1 week

[proud nova]

Around the time of that warning

[lapis root]

do you have a screenshot? the only thing i remember doing on this server is just asking questions

[lapis root]

oxi, strange

[foggy rapids]

https://docs.unity3d.com/Manual/CollidersOverview.html
says a lot about when trigger messages are sent at the bottom

[hoary scroll]

I have a box that I can push, constrained so that it can only slide in the z-direction.
I have 2 "stoppers" that collide with the box to keep it from moving past certain points.
However, when I push the box, it'll sometimes clip into the stoppers and very occasionally it'll pop out through the stoppers.

how can I keep that from happening?

[fleet island]

@bleak umbra i know you weren't doing 'a bit' but that whole triggers / colliders thing read like 'whos on first'

[subtle elm]

yeah idk @bleak umbra weird but it doesnt work

cause you are right i think

maybe it's cause my main trigger is a meshCollider

[bleak umbra]

well, in my experience collider/trigger callbacks are female dogs

[subtle elm]

😂

[bleak umbra]

do you have convex mesh checked?

[subtle elm]

yeah and trigger

[bleak umbra]

and you only get one entry in the list? which one actually? and do you clear in Late, Update or Fixed?

[subtle elm]

so basically I populate.. run some code and then clear it..

so basically:
OnTriggerStay (Collider coll)
{
List.Add(Coll);
// DoSomething
List.Clear();
}

[bleak umbra]

move the clear to FixedUpdate

[subtle elm]

this runs every frame ofc. and it's only picking up 1 collider or trigger at most

hm alright

Actually I can do it without a clear... By just declaring them inside of the scope

[bleak umbra]

with that code you get all collisions, but after adding it, you are immediately deleting it again. you will get multiple calls to OnTriggerStay... one for each other collider

[subtle elm]

a local variable... and that dont make a difference either

this way i dont have to clear it

still doesn't work though

[bleak umbra]

List<Collider> _list = new List<Collider>();

private void OnTriggerStay(Collider other)
{
    _list.Add(other);
    Debug.Log($"{Time.frameCount} - {other.name} is colliding, {_list.Count} collisions detected so far.");
}

private void FixedUpdate()
{
    // do stuff with all colliders
    
    Debug.Log($"{Time.frameCount} - Clearing {_list.Count} collisions.");
    _list.Clear();
}

[subtle elm]

Alright I'll try it

I'm still getting a count of 1

already tried this btw

[bleak umbra]

yes, had a typo

[bleak umbra]

edited the code above with some debugging and fixed the bug

[subtle elm]

alright I'll try it out

this worked already

you're a hero

I compeltely forgot about the order of executions!

FixedUpdate comes after Ontrigger and Oncollsion?

[bleak umbra]

not exactly. it happens at some point, not on every frame, and onTrigger can happen multiple times at any time between fixedupdate

[subtle elm]

the "before fixedupdate" fixed it

it's very weird though that i couldnt get this effect on the stack... it clearly has to be on the heap

[bleak umbra]

This part in the doc is important: OnTriggerStay is called --> almost <-- all the frames for every Collider other that is touching the trigger.

[subtle elm]

thats just confusing

[foggy rapids]

fixedupdate happens before trigger/collision callbacks

[subtle elm]

im making something very dynamic so that's totally fine

so yeah

why couldnt i just declare a local with every onstay loop?

[bleak umbra]

cause it gets called may times

[subtle elm]

so thats why it has to be on the heap okay i get it

[bleak umbra]

so you would only ever catch one "other" in that particular callback

[subtle elm]

wow

i was this close to going to sleep and overhauling it tomorrow

I'ms o glad I asked and so glad you were online

thanks dude

[foggy rapids]

if you want to do it on the stack, use the overlap functions 👍

[subtle elm]

yeah the overlap isnt gonna work for me, i need a procedurally generated mesh collider

but I'm super happy now thank you!

and @bleak umbra it does work on colliders (non-triggers)... detecting the colliders with a trigger

just letting you know

[foggy rapids]

https://docs.unity3d.com/ScriptReference/Rigidbody.SweepTestAll.html is a thing too

[bleak umbra]

good to know. i was hoping that i was wrong on that point.

[bleak umbra]

there is plenty of magic in the physics API to do really fancy and optimized stuff, just wish it wasn't so obtuse at times. The low level overlap functions are probably the most reliable and clean way to do most things. At leas for me, callbacks get complicated quick.

[subtle elm]

this is interesting 😮 what does it do?

is it like a slice?

[bleak umbra]

takes a shape and moves (virtually) it through space to see if anything is in its way

[foggy rapids]

it's basically doing the work that triggers those events manually and getting an array in response

[subtle elm]

i srsly once googled for slicecast.. idk.. i couldnt come up with the terminology 😂

😮

oh damn that's cool

alright

hmm

[foggy rapids]

most of the time tho, the callbacks can suit your needs 👍 but sometimes it's nicer to have the collection and logic in the same place

[subtle elm]

what if you want to simulate a frustum shape?

[foggy rapids]

i.e. if there are thousands of them, it's gonna take a lot of time to call thousands of OnTriggerStay functions 😄

[bleak umbra]

use a convex mesh collider with a frustum shape...

[subtle elm]

Already am

Thanks so much guys

[bleak umbra]

but frustum testing is usually done by comparing the frustum planes with the colliders... thats more efficient.

[vocal trench]

Need to ask just make sure I'm not missing anything - is there no way to ignore a collision as it happens like this?

private void OnCollisionEnter2D(Collision2D collision)
{
  Physics2D.IgnoreCollision(collision.otherCollider, collision.collider);
  // No collision should happen here
}

I've tried, but in this use case I'm unable to use layers or tags, and I can't use a trigger volume to detect overlap and disable collision that way.

[grizzled sapphire]

https://forum.unity.com/threads/experimental-contacts-modification-api.924809/
There was something experimental for 3d

[vocal trench]

Legend!! Downloading the alpha right now. I'm making a 2D game but I'll try switching to Physics3D and just constrain the axes for now

[iron wing]

How could I fix that problem ?

[iron wing]

(please ping me if anyone has an answer)

[foggy rapids]

if it's a tilemapcollider then the problem is colliding with the corners of tiles. there's no easy way around it but some solutions involve: using box colliders so there are no edges to catch, recognizing when things are sliding and handling that case specifically, using circle colliders for the sliding objects and having them roll

[ember grail]

how can i make the cubes touch each other? Am using the MeshRenderer to calculate the bounds and this is what happens when i try to place them next to each other

[supple sparrow]

Uhm strange. Renderer bounds are in world space IIRC so don't always match the shape, especially if rotated but it doesnt look like so in your case

DId you try with the MeshFilter bounds ?

And why not use collider ?

[ember grail]

Collider mashes them all together, I don't think I've tried with MeshFilter

[timid dove]

OnCollisionEnter is too late. You either do the experimental contact modification thing or ignore the collision before it happens

[iron wing]

It's a movable thing, and it has a box collider (so your solution is already set in this case :/)

[summer drum]

Guys, quick q,

is there a way I can do some small-scale fake soft body mesh deformation

without some hardcore math or external assets?

Just using Unity's built-in stuff?

[timid dove]

maybe a bunch of spheres connected by joints?

[summer drum]

What joint is best for this?

Not for ragdoll body per se, but like let's say I have a mesh that needs to appear soft-like (bouncy, squishable, etc.)

[timid dove]

Maybe a spring joint?

Here's an example of someone doing exactly this: https://www.youtube.com/watch?v=rR3miSZxR3k

[summer drum]

Ohh thanks! I was looking at a video from this same person, dunno how I didn't see this one haha

[vocal trench]

I tried the experimental contact modification thing, but in this specific case it looks like I'm unable to ignore these specific contacts lol

I'll see if I can rethink what I'm trying to do, if not I'll set up an example scene to show the issue

[timid dove]

any reason you can't use the things you ruled out?

• layers
• trigger volumes?

Any reason you can't ignore the collision earler on?

[vocal trench]

Each object can only collide with one other object at any given time, meaning I can't preassign to layers, and instead ignore and unignore on the fly

I added a trigger volume and it seems like OnTrigger gets called before OnCollisionStart, so I was able pre emptively disable the collision. But in this specific case (I'm setting the position of a gameobject containing a collider manually OnFixedUpdate), the collision and trigger happen at the same time and I'm unable to ignore it

That's why I switched to experimental, and ended up with the same issue - even though I ignore all contacts, this specific collision between the collider I'm manually setting the position for happens anyway

I basically want a world space collider for my rigidbody, so I make it a child and manually set it's position every fixed update. I tried having it in the actual world, but then since it's not connected to a rigidbody I can't use it for positional correction or transfer of forces without doing a workaround that didn't work out in the end

[timid dove]

What's the end goal here?

Child colliders are considered part of parent rigidbody objects

so that should work fine

[vocal trench]

Myeah, but if I make it a child it moves with the parent, and I want it to be locked in place

I'll see if I can make a demo scene that shows the issue

Appreciate the input

[summer drum]

Is there a way to get/create an armature of a model at runtime?

For example, let's say I have an item, all rigged with bones, so that I can use Spring Joints to make it softbody-like

then I do something to cut this object into many pieces

I want those new pieces to also be rigged with their original bones and have the softbody feel

[timid dove]

I think that the "armature" in Unity is basically just a combination of:

• A weight-painted mesh
• a Transform hierarchy that represents the bones
• a skinned mesh renderer

And making sure the root bone is selected here

[summer drum]

I've never worked with dynamically cutting meshes before

but if I were to do that, would that make the weight paint data be lost?

[timid dove]

no idea ¯_(ツ)_/¯

[quasi flame]

what is impulse propagation?

[cloud tartan]

@quasi flame the opposite of impulse control?

[unborn geyser]

guys i want to roate the object as mouse

[lunar egret]

Can you have collision detection without rigid body? Like I just want to be able to detect collisions, I dont care about having them move each other or gravity or any of that

[wide nebula]

Yes, using a cast. Raycast, Capsule cast, etc.

[timid dove]

You can use CharacterController

[inner hatch]

Can somebody explain me how I can make dig physics. So that the player can dig holes and stuff.

[proud nova]

It's generally not a physics thing, but a mesh editing thing.

[distant coyote]

https://assetstore.unity.com/packages/tools/terrain/digger-terrain-caves-overhangs-135178
https://assetstore.unity.com/packages/tools/terrain/digger-pro-149753

[stoic notch]

how can I make it so an object collider is only a trigger, and doesnt actually cause collisions?

I have a enemy that is supposed to be able to turn and walk up a wall. I have it so he has a detector... a collider used as a trigger... placed out front of him. When he turns, one of the trigger colliders is in the wall, where it should be, but it pushes the mob out. Even though it is a trigger

[timid dove]

Using a trigger collider should work

[stoic notch]

here is where the mod starts, detector is in the ground like it should be

it goes were its supposed to, and then gets pushed out of the wall

I have "is trigger" already enabled

Here is the way its set up... two children, two different triggers

that lower one that you can see in first two pics is the detector. The one you cant see is the wallDetector

here is the whole picture

[timid dove]

what components are on all those objects?

And what if any scripts do you have

[stoic notch]

catapillar

detector