Creating textures with compute shader not giving no results.

I am trying to create 3 textures with each pixel having random color. I have it working on CPU but I am trying to port it to GPU using compute shader. Its not working and my textures are just not being created.

C#

Code (CSharp):

1. //Create world map textures (GPU aka compute shader)
2.         if (bUseComputeShader)
3.         {
4.                 //Create render texture X
5.                 var rTextureX = new RenderTexture(worldMapTextureSize,worldMapTextureSize, 0, RenderTextureFormat.RFloat)
6.                 {
7.                     enableRandomWrite = true
8.                 };
9.                 rTextureX.Create();
10.  
11.                  //Create render texture Y
12.                 var rTextureY = new RenderTexture(worldMapTextureSize,worldMapTextureSize, 0, RenderTextureFormat.RFloat)
13.                 {
14.                     enableRandomWrite = true
15.                 };
16.                 rTextureY.Create();
17.  
18.                  //Create render texture Z
19.                 var rTextureZ = new RenderTexture(worldMapTextureSize,worldMapTextureSize, 0, RenderTextureFormat.RFloat)
20.                 {
21.                     enableRandomWrite = true
22.                 };
23.                 rTextureZ.Create();
24.  
25.                 //Do shader paramaters (0 is kernel index of world textures)(Make sure thread data is exact *8,1,1* as compute shader)
26.                 computeShader.SetTexture(0, "entityWorldTextureX", rTextureX);
27.                 computeShader.SetTexture(0, "entityWorldTextureY", rTextureY);
28.                 computeShader.SetTexture(0, "entityWorldTextureZ", rTextureZ);
29.                 computeShader.Dispatch(0, worldMapTextureSize / 8, worldMapTextureSize / 8, 1);
30.  
31.                 //Create world map texture X
32.                 worldMapTextureX = new Texture2D(worldMapTextureSize,worldMapTextureSize, TextureFormat.RGB24, false);
33.                 RenderTexture.active = rTextureX;
34.                 worldMapTextureX.ReadPixels(new Rect(0, 0,rTextureX.width, rTextureX.height), 0, 0);
35.                 worldMapTextureX.Apply();
36.  
37.                 //Create world map texture y
38.                 worldMapTextureY = new Texture2D(worldMapTextureSize,worldMapTextureSize, TextureFormat.RGB24, false);
39.                 RenderTexture.active = rTextureY;
40.                 worldMapTextureY.ReadPixels(new Rect(0, 0,rTextureY.width, rTextureY.height), 0, 0);
41.                 worldMapTextureY.Apply();
42.  
43.                 //Create world map texture z
44.                 worldMapTextureZ = new Texture2D(worldMapTextureSize,worldMapTextureSize, TextureFormat.RGB24, false);
45.                 RenderTexture.active = rTextureZ;
46.                 worldMapTextureZ.ReadPixels(new Rect(0, 0,rTextureZ.width, rTextureZ.height), 0, 0);
47.                 worldMapTextureZ.Apply();
48.         }

C# Draw Textures

Code (CSharp):

1. //Used to debug our world map texture
2.     void OnGUI()
3.     {
4.         if (!bWorldMapGUIEnabled)
5.             return;
6.  
7.         const float size = 128;
8.         const float margin = 10;
9.         GUI.DrawTexture(new Rect(0,0,size,size), worldMapTextureX);
10.         GUI.DrawTexture(new Rect(0,size + margin,size,size), worldMapTextureY);
11.         GUI.DrawTexture(new Rect(0, size + size + margin + margin,size,size), worldMapTextureZ);
12.     }

Compute shader

Code (CSharp):

1. RWTexture2D<float4> entityWorldTextureX;
2. RWTexture2D<float4> entityWorldTextureY;
3. RWTexture2D<float4> entityWorldTextureZ;
4.  
5. [numthreads(8,8,1)]
6. void CSCreateEntityWorldTextures (uint3 id : SV_DispatchThreadID)
7. {
8.      //Set world texture X pixel
9.     float r = frac(sin(dot(float2(0.1,1),float2(12.9898,78.233)))*43758.5453123);
10.     float g = frac(sin(dot(float2(0.1,1),float2(12.9898,78.233)))*43758.5453123);
11.     float b = frac(sin(dot(float2(0.1,1),float2(12.9898,78.233)))*43758.5453123);
12.     entityWorldTextureX[id.xy] = float4(r,g,b,1);
13.  
14.     //Set world texture Y pixel
15.     r = frac(sin(dot(float2(0.1,1),float2(12.9898,78.233)))*43758.5453123);
16.     g = frac(sin(dot(float2(0.1,1),float2(12.9898,78.233)))*43758.5453123);
17.     b = frac(sin(dot(float2(0.1,1),float2(12.9898,78.233)))*43758.5453123);
18.     entityWorldTextureY[id.xy] = float4(r,g,b,1);
19.  
20.      //Set world texture Z pixel
21.     r = frac(sin(dot(float2(0.1,1),float2(12.9898,78.233)))*43758.5453123);
22.     g = frac(sin(dot(float2(0.1,1),float2(12.9898,78.233)))*43758.5453123);
23.     b = frac(sin(dot(float2(0.1,1),float2(12.9898,78.233)))*43758.5453123);
24.     entityWorldTextureZ[id.xy] = float4(r,g,b,1);
25. }

 

So I got some results on gpu but not what I want. First I will show cpu results which is what I want.
you can see 3 random textures being generated on left side screen. Each pixel is just a random color.



C#

Code (CSharp):

1. //create world map texture X
2.             var worldMapTexture = new Texture2D(worldMapTextureSize,worldMapTextureSize);
3.             for (int x = 0; x < worldMapTextureSize; x++)
4.                 for (int y = 0; y < worldMapTextureSize; y++)
5.                     worldMapTexture.SetPixel(x,y, UnityEngine.Random.ColorHSV(0.2f, 1f, 0.2f, 1f, 0.2f, 1f));
6.             worldMapTexture.Apply();
7.  
8.             //create world map render texture x from above texture
9.             worldMapRenderTextureX = new RenderTexture(worldMapTextureSize / 2 ,worldMapTextureSize / 2,0);
10.             Graphics.Blit(worldMapTexture, worldMapRenderTextureX);
11.  
12.             //create world map texture y
13.              for (int x = 0; x < worldMapTextureSize; x++)
14.                 for (int y = 0; y < worldMapTextureSize; y++)
15.                     worldMapTexture.SetPixel(x,y, UnityEngine.Random.ColorHSV(0.2f, 1f, 0.2f, 1f, 0.2f, 1f));
16.             worldMapTexture.Apply();
17.  
18.             //create world map render texture x from above texture
19.             worldMapRenderTextureY = new RenderTexture(worldMapTextureSize / 2 ,worldMapTextureSize / 2,0);
20.             Graphics.Blit(worldMapTexture, worldMapRenderTextureY);
21.  
22.              //create world map texture y
23.              for (int x = 0; x < worldMapTextureSize; x++)
24.                 for (int y = 0; y < worldMapTextureSize; y++)
25.                     worldMapTexture.SetPixel(x,y, UnityEngine.Random.ColorHSV(0.2f, 1f, 0.2f, 1f, 0.2f, 1f));
26.             worldMapTexture.Apply();
27.  
28.             //create world map render texture x from above texture
29.             worldMapRenderTextureZ = new RenderTexture(worldMapTextureSize / 2 ,worldMapTextureSize / 2,0);
30.             Graphics.Blit(worldMapTexture, worldMapRenderTextureZ);

Now here is gpu results. I am just getting red textures for some reason.



Compute shader

Code (CSharp):

1. RWTexture2D<float4> entityWorldTextureX;
2. RWTexture2D<float4> entityWorldTextureY;
3. RWTexture2D<float4> entityWorldTextureZ;
4.  
5. [numthreads(8,1,1)]
6. void CSCreateEntityWorldTextures (uint3 id : SV_DispatchThreadID)
7. {
8.     //rand (is range)
9.     float2 rand = float2(0,1);
10.  
11.     //Set world texture X pixel
12.     float r = frac(sin(dot(rand .xy, float2(12.9898, 78.233))) * 43758.5453);
13.     float g = frac(sin(dot(rand .xy, float2(12.9898, 78.233))) * 43758.5453);
14.     float b = frac(sin(dot(rand .xy, float2(12.9898, 78.233))) * 43758.5453);
15.     float a = 1;
16.     entityWorldTextureX[id.xy] = float4(r,g,b,a);
17.  
18.     //Set world texture Y pixel
19.     r = frac(sin(dot(rand .xy, float2(12.9898, 78.233))) * 43758.5453);
20.     g = frac(sin(dot(rand .xy, float2(12.9898, 78.233))) * 43758.5453);
21.     b = frac(sin(dot(rand .xy, float2(12.9898, 78.233))) * 43758.5453);
22.     a = 1;
23.     entityWorldTextureY[id.xy] = float4(r,g,b,a);
24.  
25.     //Set world texture Y pixel
26.     r = frac(sin(dot(rand .xy, float2(12.9898, 78.233))) * 43758.5453);
27.     g = frac(sin(dot(rand .xy, float2(12.9898, 78.233))) * 43758.5453);
28.     b = frac(sin(dot(rand .xy, float2(12.9898, 78.233))) * 43758.5453);
29.     a = 1;
30.     entityWorldTextureZ[id.xy] = float4(r,g,b,a);
31. }

 

So the function just does not seem to work at all. Its return all black textures. Not sure what I am doing wrong. Perhaps its numthreads or something?

Code (CSharp):

1.  
2. Compute shader
3. [numthreads(8,8,1)]
4. void CSCreateEntityWorldTextures (uint3 id : SV_DispatchThreadID)
5. {
6.     //Should be gray
7.     entityWorldTextureX[id.xy] = float4(0.5, 0.5, 0.5, 1);
8.  
9.     //Should be blue
10.     entityWorldTextureY[id.xy] = float4(0,1,0,1);
11.  
12.     //Should be green
13.     entityWorldTextureZ[id.xy] = float4(0,0,1,1);
14. }

C#

Code (CSharp):

1. computeShader.Dispatch(0, worldMapTextureSize / 8, worldMapTextureSize / 8, 1);

 

At glance seems you are creating your render textures as RFloat, which only contain a single channel, but your compute shader expects a texture with four channels. Maybe that's the problem?

 

Thanks. I got it working. I was creating render texts in C# wrong by typo.

I had

Code (CSharp):

1.  worldMapRenderTextureX = new RenderTexture(worldMapTextureSize,0, worldMapTextureSize);

Supposed to be

Code (CSharp):

1.  worldMapRenderTextureX = new RenderTexture(worldMapTextureSize,worldMapTextureSize,24);
2.  
3. Not sure how typo happened when I did it right in CPU version.
4.  
5. Thanks anyway.