// Attach this to a gameObject that has a renderer.
// Copies any property mat has and assigns it to this transform material

var mat : Material;

if (!mat) {
    Debug.LogError("Assign a material on the inspector.");
    return;
}

renderer.material.CopyPropertiesFromMaterial(mat);

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    public Material mat;
    void Example() {
        if (!mat) {
            Debug.LogError("Assign a material on the inspector.");
            return;
        }
        renderer.material.CopyPropertiesFromMaterial(mat);
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    public mat as Material

    def Example():
        if not mat:
            Debug.LogError('Assign a material on the inspector.')
            return
        renderer.material.CopyPropertiesFromMaterial(mat)