Unity3D NGUI刮刮卡效果

线上效果 

确保你的纹理的read/write 是勾选的，纹理格式是 RGBA32的

//代码

using UnityEngine;

[RequireComponent(typeof(UITexture))]
public class ChangeTexturePixel : MonoBehaviour {
	private UITexture mUITex;
	private Texture2D MyTex;
	public int Radius = 10;
	public Color Col = new Color(0,0,0,0);
	void Awake()
	{
		mUITex = GetComponent<UITexture>();
		var tex = mUITex.mainTexture as Texture2D;
		MyTex = new Texture2D(tex.width, tex.height, tex.format, false);
		MyTex.SetPixels(tex.GetPixels());
		MyTex.Apply();
		mUITex.mainTexture = MyTex;
	}

	void ChangePixelColorByCircle(int x, int y, int radius, Color col)
	{
		for (int i = -Radius; i < Radius; i++)
		{
			var py = y + i;
			if (py < 0 || py >= MyTex.height)
			{
				continue;
			}

			for (int j = -Radius; j < Radius; j++)
			{
				var px = x + j;
				if (px < 0 || px >= MyTex.width)
				{
					continue;
				}
				if (new Vector2(px - x, py - y).magnitude > Radius)
				{
					continue;
				}
				MyTex.SetPixel(px, py, Col);
			}
		}
		MyTex.Apply();
	}

	int[] WorldPos2Pix(Vector3 worldPos)
	{
		var temp = transform.InverseTransformPoint(worldPos);
		var pos = new Vector2(temp.x+mUITex.width/2,temp.y+mUITex.height/2);
		float rateX = mUITex.width / (float)MyTex.width;
		float rateY = mUITex.height / (float)MyTex.height;

		return new []
		{
			(int)(pos.x / rateX), (int)(pos.y/rateY)
		};
		
	}

	void Update ()
	{
		if (Input.GetMouseButton(0))
		{
			Vector3 worldPos = UICamera.currentCamera.ScreenToWorldPoint(Input.mousePosition);
			var posA = WorldPos2Pix(worldPos);
			ChangePixelColorByCircle(posA[0], posA[1], Radius, Col);
		}
	}
}