Wheels on different physics objects.

News & General Discussion
1

Tarmac and gravel. Ice and grass. Gummy bears and banana skins.

From the Unity manual: The reported hit is always the closest one. Because the tire friction model does not automatically respond to other PhysicMaterials, any simulation of different ground materials must be done manually by adjusting forwardFriction and sidewaysFriction based on collider’s material returned here.

So, wheel colliders don’t react to physics materials. And to make this happen you have to do it yourself. Thanks. That helps no end.

The slightest wiff of a suggestion as to how might have been an idea when writing this ‘help’ page, but obviously beyond the pay of the author.

I’ve looked at the grounded and hit stuff, but I can’t see anywhere how I’d get the object the wheel is currently touching, only the current friction data. I need to get the object the wheel is touching then change some friction stuff.

I’m sure this is completely obvious to someone who knows the WC intimately, but I don’t. Could someone please give me a pointer?

Thanks.

2

void OnCollisionStay(Collision collisionInfo)
{
Debug.Log(“TOUCHING SOMETHING”);
}

In theory, looking at the manual and from some other posts this should work. However nothing gets sent to the log at all. This in in a script that is connected to 4 wheel colliders in my scene which are (hopefully) always going to be on the ground, so the log should be going nuts.

Could someone please let me know why this isn’t getting called (when it should be every frame) and how I make it get called? Or does this not work and I should be using something else?

Thanks again.

3

is your ground using box colliders or mesh colliders

4

Mesh. Is that the problem?
Can I use a mesh? If the floor has to be a big box that will be a problem!