unity material offset script

using UnityEngine;public class Example : MonoBehaviour
{
    // Scroll main texture based on time    float scrollSpeed = 0.5f;
    Renderer rend;    void Start()
    {
        rend = GetComponent<Renderer> ();
    }    void Update()
    {
        float offset = Time.time * scrollSpeed;
        rend.material.SetTextureOffset("_MainTex", new Vector2(offset, 0));
    }
}