Problem with Color Correction and 3D LUT

lipsryme · 2013-05-19T00:55:31

I'm having some issues with color correction using a 3D LUT. I'm using a neutral LUT 16x16x16 from the UnrealEngine page here: http://udn.epicgames.com/Three/rsrc/Three/ColorGrading/RGBTable16x1.png I've open it up in photoshop and saved it as a Volume Texture DDS (32bpp unsigned ARGB8) using the nvidia plugin. And here's my shader: float4 PS(in VSOutput input) : SV_Target { float3 rawColor = InputTexture0.Sample(LinearClampSampler, input.UV).rgb; float3 scale = (float3(16, 16, 16) - 1.0f) / float3(16, 16, 16); float3 offset = 1.0f / (2.0f - float3(16, 16, 16)); float3 colorCorrected = LUT.Sample(LinearClampSampler, scale * rawColor + offset).rgb; return float4(colorCorrected, 1.0f); } The code is from this sample here: http://http.developer.nvidia.com/GPUGems2/gpugems2_chapter24.html Can someone spot the problem ? : / Not sure if the problem has to do with the order of rendering. I'm currently tonemapping my linear result to a R8G8B8A8_UNORM_SRGB target, then use this as the input for the color correction which then outputs to my R8G8B8A8_UNORM_SRGB backbuffer. Here's a screen of what my result looks like: http://d.pr/i/xGYR And here's the original for comparison: http://d.pr/i/I6SL