- pixels are bucketed into bilateral grid on fixed size tiles (64x64)
- when ViewRect is not a multiple of the tile size, sampling the bilateral grid requires applying a scale to ViewportUV.
#jira UE-177099
#rb none
[CL 26704166 by tiago costa in ue5-main branch]
- Image exposure is locally adjusted by decomposing luminance of the frame into a base layer and a detail layer.
- Base layer contrast can be reduced while preserving detail.
- Support blending with gaussian blurred luminance as proposed in Advances in Real-Time Rendering in Games 2021.
- Controls in PostProcessVolume.
- r.LocalExposure cvar to control whether local exposure is supported.
- Visualization mode in "Show->Visualize->Local Expsoure". Multiple modes controllable using r.LocalExposure.VisualizeDebugMode.
- Bilateral grid generation not yet optimized. Optimization should include increasing depth of grid to match histogram size so that global histogram can be generated from grid.
- Added option to use mirror address mode in PostProcessWeightedSampleSum, since black border adds noticeable vignetting to the blurred luminance.
#preflight 612f65169db3090001ba3eec
#rb Brian.Karis, Guillaume.Abadie, Krzysztof.Narkowicz
#ROBOMERGE-SOURCE: CL 17385317
#ROBOMERGE-BOT: (v865-17346139)
[CL 17387198 by tiago costa in ue5-main branch]