I would like to get the red, green and blue color values of a specific pixel in a compute shader. But unfortunately the values I get are always lower than the correct value unless it is 0 or 1.
To test this I have created a shader that writes a certain color in a pixel:
fixed4 frag() : SV_Target
{
return _Color;
}
And read the value in the compute shader:
RWStructuredBuffer _Color;
Texture2D _Source;
...
if (dispatchThreadId.x == 990 & dispatchThreadId.y == 1038)
{
float3 color = _Source[dispatchThreadId].rgb;
_Color.x = color.r;
}
The compute shader is called in OnRenderImage:
private void OnRenderImage(RenderTexture source, RenderTexture destination)
{
int kernel = m_ComputeShader.FindKernel("KCompute");
m_ComputeShader.SetBuffer(kernel, "_Color", m_Buffer);
m_ComputeShader.SetTexture(kernel, "_Source", source);
m_ComputeShader.Dispatch(kernel, Mathf.CeilToInt(source.width / 16f), Mathf.CeilToInt(source.height / 16f), 1);
}
Unfortunately the written and the read values are not equals. If I write for example a 0.5 in the shader, I get a 0.2 in the compute shader. Only if a 0 or a 1 is written, it is the same in the compute shader.
I am pretty sure that the writing is correct, as I exported the Texture as png in the OnRenderImage and validated the pixel color of the png in Gimp.
Do you have any ideas how I can get the correct values?
Does it perhaps have something to do with the sRGB?
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