Question question about colliders

[telobarsik]

hi.
why do colliders of some atoms interact differently with hair?
For example, the capsule affects hair, but the cube does not?
As for the slate and wooden floor panels, when changing their scale, their colliders do not scale!
The "custom unity asset" collider turns off and does not interact with anything at all if you enable physics!
Is there a plugin that fixes these problems?

 

[murn]

I too would like to know why the cube does not collide with the hair. ( I think I read it somewhere a few days ago why it's like that but I can't remember) You can make your own or use atani's sub scene I think some of the shapes used in atani's scene has the alpha material turned all the way down so some of them are not seen.

 

[telobarsik]

I too would like to know why the cube does not collide with the hair. ( I think I read it somewhere a few days ago why it's like that but I can't remember) You can make your own or use atani's sub scene I think some of the shapes used in atani's scene has the alpha material turned all the way down so some of them are not seen.

yes, thanks, I make a collider from capsules myself, but it's not as effective as if we could make a plugin that allows you to control the collision properties of any atom in the scene.
I still hope that this is possible.

 

[hazmhox]

For example, the capsule affects hair, but the cube does not?

Probably an oversight from meshed.

The "custom unity asset" collider turns off and does not interact with anything at all if you enable physics!

If you're refering to actual CUAs, it should not! If you have that behavior the CUA is probably badly made/broken.

if we could make a plugin that allows you to control the collision properties of any atom in the scene.

No we could not

Let's contextualize that:

1. For hairs/clothes, the collision system is GPU based, so we would need a specific collider setup to handle this on custom assets. This is not something we have access to, hence why nobody has came up with a solution.
   
   
2. An object ( in general ) has not collision by default. It's not because you "see" a sphere ingame that its collision is a sphere. The devs/artists needs to create a collision for it. Making a plugin being able to create collisions is a bit more complex than simply "enabling" something. You would need to be able to choose your collider type, edit it's size, position, properties.
   
   So joke aside, yes we could. Is it easy? No. Either from a user perspective or a dev perspective.

 

[SlimerJSpud]

One thing that bothers me in Vam is that long hair has ends that wiggle like crazy when the model is just standing there. The only way I've found to stop that is to turn off breast hard colliders. Some hairs are worse than others. I use Atani's hair collider now in scenes where a person is lying down on some CUA bed or something and I want the hair to spread out on the surface. The ends wiggling can even happen when a model is lying down. The wiggling is always near the breasts. I consider this a bug in Vam, that hair can defy physics like this.

 

[telobarsik]

One thing that bothers me in Vam is that long hair has ends that wiggle like crazy when the model is just standing there. The only way I've found to stop that is to turn off breast hard colliders. Some hairs are worse than others. I use Atani's hair collider now in scenes where a person is lying down on some CUA bed or something and I want the hair to spread out on the surface. The ends wiggling can even happen when a model is lying down. The wiggling is always near the breasts. I consider this a bug in Vam, that hair can defy physics like this.

try adjusting the hair physics parameter "friction" and "snap"

 

[telobarsik]

For hairs/clothes, the collision system is GPU based

i.e. the capsule collider is based on the GPU, since it interacts with hair?

 

[hazmhox]

yup! it's not a standard Unity collider : )

 

[telobarsik]

If you're refering to actual CUAs, it should not! If you have that behavior the CUA is probably badly made/broken.

I double-checked, I can't make it so that the collisions of the CUA are not disabled when physics is turned on.

With shapes (cube, sphere, etc.) everything works as expected, when I turn on physics and gravity for a cube, it falls to the floor and stays there thanks to the collision, but with the CUA this does not work, the CUA always falls through the floor.

 

[hazmhox]

With shapes (cube, sphere, etc.) everything works as expected, when I turn on physics and gravity for a cube, it falls to the floor and stays there thanks to the collision, but with the CUA this does not work, the CUA always falls through the floor.

This is a different problem. This is due to the collision setup. Collision can work, but the going through the floor is an incorrect collider setup for fast moving objects. This is explained in this at the B - Create sub-colliders if you want to use prefabs as physical objects chapter.

 

[SlimerJSpud]

try adjusting the hair physics parameter "friction" and "snap"

These adjustments only helped a little. They did not cure the problem.

 

[telobarsik]

This is a different problem. This is due to the collision setup. Collision can work, but the going through the floor is an incorrect collider setup for fast moving objects. This is explained in this at the B - Create sub-colliders if you want to use prefabs as physical objects chapter.

thank you, this clarifies the situation a little.
I have tried many CUAs downloaded from this resource, I have not yet come across a single one that had collisions with working physics))
so it turns out that the shapes of the VaM (cube, sphere...) have two colliders?

 

[hazmhox]

so it turns out that the shapes of the VaM (cube, sphere...) have two colliders?

They have probably one collider, but a basic one Sphere, or Cube collider. Those are fast and can handle fast motions. Mesh collider are very bad for perfs and extremely slow at computing the collisions. It's quite ok for slow motions, or static objects tho.

 

[telobarsik]

It's quite ok for slow motions, or static objects tho.

i.e. if I reduce gravity so that the object falls very, very slowly, it won't fall through the floor?

 

[hazmhox]

i.e. if I reduce gravity so that the object falls very, very slowly, it won't fall through the floor?

Possibly! But not guaranteed