Wheel Collider has different rotation with the wheel GameObject

Question

I want to add a wheel collider in my car wheel but it comes with 90-degree rotation.

This is the image:

How can I adjust the collider to the car wheel?

Answer 1

One of the best thing you could do is that, before importing the game object, make sure that the game object is Y Forward. You can change that in blender while exporting.

Answer 2

For further reference, i am writing down my comment as answer.

Simplest solution that i can think of is; add an empty gameObject. Attach wheel collider to that empty gameObject. And make the empty gameObject child to your car's wheel. With this you can rotate the empty gameObject so that your collider will be rotate. @Programmer also shared a link about WheelCollider Tutorial. Which can be found here

Answer 3

I had the same problem. However, simply rotating an empty parent object doesn't work in the modern version of Unity (2019.4). You have to rotate an object that has the rigidbody that the WheelColliders are attached to.

Assuming that your car has a rigidbody, the solution is to make sure that the X-axis orientation of the car's rigidbody matches the desired X-axis orientation of the wheel colliders.

Based on this post:

https://forum.unity.com/threads/unity-5-wheelcollider-wrong-rotation.349596/#post-2264801

WheelColliders always point in the "forward" and "down" direction as the rigidbody they're attached to. The steerAngle value is relative to the rigidbody's forward direction.

Please bear in mind, however, that your car's model(the visuals that display the car body) might have a different orientation from the object that contains the rigidbody that wheel colliders are attached to.

In my case Hierarchy looked like so:

• MainScene
  • CarRoot
    • CarModel
    • WheelColliders
      • Wheel_FR
      • Wheel_FL
      • Wheel_RR
      • Wheel_RL

The CarRoot had a rigid body on it. When I rotated it, it would rotate the wheel colliders with it. That would also rotate the car model. Which was not good. So I had to:

1. Unparent the CarModel and WheelColliders(made them children of MainScene)
2. Rotate the CarRoot by 90 degrees on the Y-axis(to align its X-axis with that of the WheelColliders)
3. Make CarModel and WheelColliders children of CarRoot again.

That did it for me.

P.S. Sorry if this is a bit of a necro-bump. But this still has no answer.

Answer 4

I had a ton of trouble over this because none of the export settings or rotations in Blender fixed the problem for me. I eventually found a solution though. Create an empty gameObject, and attach the rigidbody, mesh filter, and mesh collider to it. Then parent the model to the empty gameObject, and then try adding wheel colliders. Wheels are relative to the rigidbody's transform.up and transform.forward, so putting the rigidbody on a default thing fixes all the issues.