材质球图片的运动

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PaTiJianTou : MonoBehaviour {

   
    [Range(0f, 1f)]
    public float speed_x = 0;
    [Range(0f, 1f)]
    public float speed_y = 0;
    private Material mater;
    float x = 0;
    float y = 0;

    // Use this for initialization
    void Start () {
        mater = this.GetComponent<MeshRenderer>().material;
    }
    
    // Update is called once per frame
    void Update () {
        if (mater != null)
        {
            x += Time.deltaTime * speed_x;
            y += Time.deltaTime * speed_y;
            mater.SetTextureOffset("_MainTex", new Vector2(x, y));
        }
       
    }
}