Sampling in the Compute Shader not working

Question

I'm trying to sample a image in the compute shader.

My code is

    [numthreads(1, N, 1)]
void VertBlurCS(int3 groupThreadID : SV_GroupThreadID,
                int3 dispatchThreadID : SV_DispatchThreadID)
{

    float4 test = gDiffuseMap.SampleLevel(samAnisotropic,0,0);
    gOutput[dispatchThreadID.xy] = test;
}

I'm getting one solid color.

What is wrong with my code?

Answer 1

You are sampling from the same location on the texture for every output, therefore the output is a single colour.

See the documentation for SampleLevel

A fix would look something like this:

float2 uv = float2(dispatchThreadID.xy) / float2(textureWidthHeight); float4 test = gDiffuseMap.SampleLevel( samAnisotropic, uv, 0 );