Creating an OCIO view transform to match default Unreal 4 ACES viewport tonemapper

Discussions - Using ACES VFX
7

Hi Brian, the function effectively used by UE4 in Engine/Shaders/Private/PostProcessCombineLUTs.usf is FilmToneMap defined in Engine/Shaders/Private/TonemapCommon.ush. It uses a fit that includes a 1.45 gain, the function you mention is not used AFAIK and is more a reference.

Hope that helps!

Cheers,

Thomas