Writing to RenderTexture in a compute shader doesn't work on Metal

Hi,
I'm writing to RWTexture2D<float4> texture in a compute shader. It's working nicely on desktop with directx. But it doesn't work on metal with iphone or ipad.

I have tried it on 2017.4.4 and newest beta 2018.2b9 too.

Compute Shader

Code (CSharp):

1. RWTexture2D<float4> textureOut;
2. StructuredBuffer<float4> colors;  
3.  
4. #pragma kernel pixelCalc    
5.  
6. [numthreads(16,16,1)]          
7. void pixelCalc (uint2 id : SV_DispatchThreadID){
8.      textureOut[id.xy] = colors[id.x + id.y * 250];
9. }

CPU side:

Code (CSharp):

1. this.outputTexture = new RenderTexture(250, 250, 32);
2.             this.outputTexture.enableRandomWrite = true;
3.             this.outputTexture.useMipMap = false;
4.             this.outputTexture.Create();
5.  
6. this.colorArray = new Color[250 * 250];
7.  
8. // Color size is four values of four bytes, so 4 * 4
9.             this.colorsBuffer = new ComputeBuffer(this.colorArray.Length, 4 * 4);
10.  
11.             // again, we're setting color array to the buffer
12.             colorsBuffer.SetData(colorArray);
13.  
14.  
15.             var overlayGameObject = GameObject.Find("Overlay");
16.             var renderer = overlayGameObject.GetComponent<Renderer>();
17.             renderer.material.mainTexture = this.outputTexture;
18.  
19. ar kernelIndex = this.shader.FindKernel("pixelCalc");
20.  
21.             this.shader.SetBuffer(kernelIndex, "colors", colorsBuffer);
22.             this.shader.SetTexture(kernelIndex, "textureOut", this.outputTexture);
23.  
24.             this.shader.Dispatch(kernelIndex, 16, 16, 1);

Am I doing something wrong or render texture simply doesn't work in metal and compute shaders?

P.S.: I have tried an approach used here. But without success:
https://forum.unity.com/threads/con...ass-shader-to-unity-hlsl.418238/#post-3478159

Basically passing StructuredBuffer in normal shader. And bypassing usage of render texture.
Thanks
Peter

 

Lowering threads to 8 8 1 helped. I will experiment with it further but it looks like it's not working with 16 16 1.

But at least it's working with structured buffer and render rexture

 

Wow, nice find. I thought it doesn't work at all.