Unity AsyncGPUReadback 接口测试

Unity2018新加入了该接口，可以做到异步RenderTexture->像素数据和异步的ComputeBuffer.GetData

那么写了几个例子来测试下。

1.RenderTexture->Texture2D

异步：

IEnumerator Start()
{
    var rt = new RenderTexture(, , );
    //Graphics.xxx...
    var req = AsyncGPUReadback.Request(rt);
    yield return new WaitUntil(() => req.done);

    var tex = new Texture2D(, , TextureFormat.RGBA32, false);
    var colorArray = req.GetData<Color32>().ToArray();
    tex.SetPixels32(colorArray);
    tex.Apply();
}

同步：

RenderTexture.active = rt;
var tex = new Texture2D(, , TextureFormat.RGBA32, false);
tex.ReadPixels(new Rect(, , , ), , , false);
tex.Apply();

2.AsyncGPUReadback GetData

cs:

#pragma kernel CSMain

struct TestData
{
    float3 pos;
};
RWStructuredBuffer<TestData> MyData;

[numthreads(,,)]
void CSMain (uint3 id : SV_DispatchThreadID)
{
    MyData[id.x].pos = MyData[id.x].pos * ;
}

异步：

public class ComputeShaderAsyncRequest : MonoBehaviour
{
    public struct TestData
    {
        public Vector3 pos;
    }
    public ComputeShader computeShader;

    IEnumerator Start()
    {
        var kernelID = computeShader.FindKernel("CSMain");

        var testData = new List<TestData>();
        for (int i = ; i < ; i++)
            testData.Add(new TestData() { pos = new Vector3(i, , ) });

        var computeBuffer = new ComputeBuffer(testData.Count, );
        computeBuffer.SetData(testData);
        computeShader.SetBuffer(kernelID, "MyData", computeBuffer);
        computeShader.Dispatch(kernelID, , , );
        var request = AsyncGPUReadback.Request(computeBuffer);
        Debug.Log("frame1: " + Time.frameCount);//
        yield return new WaitUntil(() => request.done);
        Debug.Log("frame2: " + Time.frameCount);//

        var testDataArray = request.GetData<TestData>().ToArray();
        for (int i = ; i < testDataArray.Length; i++)
            Debug.Log("i :" + i + "item: " + testDataArray[i].pos);
    }
}

同步：

public class ComputeShaderAsyncRequest_Sync : MonoBehaviour
{
    public struct TestData
    {
        public Vector3 pos;
    }

    public ComputeShader computeShader;

    void Start()
    {
        var kernelID = computeShader.FindKernel("CSMain");

        var testData = new List<TestData>();
        for (int i = ; i < ; i++)
            testData.Add(new TestData() { pos = new Vector3(i, , ) });

        var computeBuffer = new ComputeBuffer(testData.Count, );
        computeBuffer.SetData(testData);
        computeShader.SetBuffer(kernelID, "MyData", computeBuffer);
        computeShader.Dispatch(kernelID, , , );
        var array = new TestData[testData.Count];
        computeBuffer.GetData(array);
        for (int i = ; i < array.Length; i++)
            Debug.Log("i :" + i + "item: " + array[i].pos);
    }
}