unity UV 动画

using UnityEngine;
using System.Collections;

public class UV_Animation : MonoBehaviour {
    public float _columnCount=1;//行数
    public float _rowCount=1;//列数
    public int _framePerSecond;//帧速率
    float _colIndex=0;
    float _rowIndex=0;
    bool _isPlay=false;
    float myTime=0;
    // Use this for initialization
    void Start () {
        _rowIndex=_rowCount-1;
    }
    
    // Update is called once per frame
    void Update () {
        //改变帧速率
        myTime+=Time.deltaTime;
        _colIndex=Mathf.Floor(myTime*(_framePerSecond-1));
        //计算行列位置
        _colIndex=_colIndex%_columnCount;
        if(_colIndex!=0){
            _isPlay=true;
        }
        if(_isPlay){
            if(_colIndex==0){
                _rowIndex--;
                Debug.Log("1="+_rowIndex);
                if(_rowIndex==-1){
                    _rowIndex=_rowCount-1;
                }
                _isPlay=false;
            }
        }
        //改变贴图uv值
        renderer.material.mainTextureScale=new Vector2 (1/_columnCount,1/_rowCount);
        renderer.material.mainTextureOffset=new Vector2(1/_columnCount*_colIndex,1/_rowCount*_rowIndex);
    }
}