Strange issue with Shpere, mesh and box colliders and wheel

Unity Engine
1

Hi,

I have a very strange problem on my project. I should create a car like in the Unity Car tutorial or the Jcar demo.

I created my car with this hierarchy in the Editor.

  • Root Node Object
    with rigidbody component
  • Collider Root
  • Colliders GameObject with collider component
  • …etc…
  • GameObject Car Model
  • Wheel
  • Wheel
  • Body
  • Others nodes from my model
  • …etc…
  • Wheel Colliders GameObject
  • WheelCollider Component
  • Wheel Colliders GameObject
  • WheelCollider Component

If, I use box, sphere or mesh collider component in the gameobject colliders. When I start the scene, the car go in the air and fall few seconds after with the gravity. But collide with the terrain without touch it and stay motionless like that!!!

But, if I use a capsule collider, I don’t have any problem!

In both case, the colliders doesn’t touch wheel colliders and they are in the right dimensions with the mesh size.

If I don’t use a collider into the Colliders GameObject, I don’t have any issue too.

I don’t understand where is the source of my problem. Do you have an idea, please?

Thanks you for your help.

Best Regards
Samuel

2

Try pressing the pause button down, then pressing play and switching back to the scene view. Now, select the car object and unpause gameplay. You should be able to see what the car’s colliders are doing in the scene. If they are moving in an unpredictable way, it might give a clue as to what is going wrong.

3

Hi andeeee,

I found the problem. It is very stupid. I unchecked the convex mode for the road object’s collider.

Now I can tune my car’s physic model.

Thanks you for your tip.

Best Regards