Rigidbody.angularVelocity

Description

The angular velocity vector of the rigidbody.

In most cases you should not modify it directly, as this can result in unrealistic behaviour.

// Change the material depending on the speed of rotation
var fastWheelMaterial : Material;
var slowWheelMaterial : Material;

var rb: Rigidbody;
var rend: MeshRenderer;

function Start() {
	rb = GetComponent.<Rigidbody>();
	rend = GetComponent.<MeshRenderer>();
}

	
function Update () {
	if (rb.angularVelocity.magnitude < 5) {
		rend.sharedMaterial = slowWheelMaterial;
	}	
	else {
		rend.sharedMaterial = fastWheelMaterial;	
	}
}

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public Material fastWheelMaterial;
    public Material slowWheelMaterial;
    public Rigidbody rb;
    public MeshRenderer rend;
    void Start() {
        rb = GetComponent<Rigidbody>();
        rend = GetComponent<MeshRenderer>();
    }
    void Update() {
        if (rb.angularVelocity.magnitude < 5)
            rend.sharedMaterial = slowWheelMaterial;
        else
            rend.sharedMaterial = fastWheelMaterial;
    }
}