Resolved Error when attempting to read from input RWTexture2D<float4>

Hello!

I am fairly new to writing compute shaders, so please bare with me.
I am creating a custom mesh in Unity3D, but I am doing it through the use of the GPU. However, while I can happily write to a RWTexture2D<float4> without issue, reading from it is a bit different.

The offending HLSL code (I only need the first line of pixels at this stage):

Code (CSharp):

1. #pragma kernel SubdivideMesh
2.  
3. float size;
4. RWTexture2D<float4> InputTrigData;
5. RWTexture2D<float4> OutputTrigData;
6.  
7. [numthreads(8, 8, 1)]
8. void SubdivideMesh(uint3 id : SV_DispatchThreadID) {
9.   int index = id.x;
10.  
11.   float4 origPos1 = InputTrigData[index][0];
12.  
13.   //Make modifications to "origPos1" here
14.  
15.   OutputTrigData[index][0] = origPos1;
16. }
17.  

The error being thrown is:

Code (CSharp):

1. Shader error in 'PGSFirstWorld.compute': invalid type for index - index must be a scalar, or a vector with the correct number of dimensions at kernel SubdivideMesh at PGSFirstWorld.compute(54) (on d3d11)

which is referring to how I'm trying to get the float4 (RGBA) out of the RWTexture2D<float4>. Am I missing something here about how textures work on the GPU? I thought that RWTexture2D variables are treated just like a standard 2D array of float4's, so you can just do "InputTrigData[X co-ordinate][Y co-ordinate]" and just have a float4 come out?

I am incredibly confused, and it seems like such an incredibly simple thing I'm trying to do. Just read a pixel from the incoming texture and save that as a float4.

Any help would be greatly appreciated!

 

Edit: I found a different way around it using "RWStructuredBuffer<float3>" using the "ComputeBuffer" class which works perfectly for this project. However, I am still curious as to how to access 2D textures on the GPU like above for a different project later on.

 

Almost!

Code (CSharp):

1. uint2 index = uint2(id.x, 0);
2. OutputTrigData[index] = InputTrigData[index];

 

Thankyou so much! I knew I couldn't have been far off the mark.

I shall keep this in mind next time I work with 2D textures, which should be very soon!