利用GPU处理大量繁琐的计算，以图像抠图为例（入门级）

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using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class MattingTexture : MonoBehaviour
{
public Texture2D inputTexture;//输入图片
public RawImage outputImage;//输出显示框
public ComputeShader shader;
int k;
RenderTexture t;//输出图片
// Use this for initialization
void Start ()
{
t = new RenderTexture(inputTexture.width, inputTexture.height, 24);
t.enableRandomWrite = true;
t.Create();
outputImage.texture = t;
k = shader.FindKernel("CSMain");
}
// Update is called once per frame
void Update () {
}
public void StartChange()
{
shader.SetTexture(k, "inputTexture", inputTexture);
shader.SetTexture(k, "outputTexture", t);
shader.Dispatch(k, inputTexture.width / 8, inputTexture.height / 8, 1);
}
}

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// Each #kernel tells which function to compile; you can have many kernels
#pragma kernel CSMain
Texture2D inputTexture;
RWTexture2D <float4> outputTexture;
[numthreads(8,8,1)]
void CSMain (uint3 id : SV_DispatchThreadID)
{
// TODO: insert actual code here!
//for (int a = 0;a < dataCount;a++) {
//	if (textureData[a].intR > minR) {
//
if (textureData[a].intG < maxG) {
//
if (textureData[a].intB < maxB) {
//
continue;
//
}
//
}
//	}
//	textureData[a].intA = 0;//不满足条件设为透明
//}
float R = inputTexture[id.xy].r;
float G = inputTexture[id.xy].g;
float B = inputTexture[id.xy].b;
float A = 1;
if (R > 0.5) {
if (G < 0.1) {
if (B < 0.2) {
R = G = B = 1;
//A = 1;
}
}
}
outputTexture[id.xy] = float4(R, G, B, A); //过滤RGB
}