7bb512594c
This makes the lighting a bit more diffuse but don't produce negative values. Add a bias of 1.5f to make the lighting a bit more directionnal. The implementation is based on: https://github.com/kayru/Probulator/blob/master/Source/Probulator/SphericalHarmonics.h#L136 which is derived from: http://www.geomerics.com/wp-content/uploads/2015/08/CEDEC_Geomerics_ReconstructingDiffuseLighting1.pdf The shader implementation is optimized and has the same runtime cost as previous method: * no sh eval : 0.13ms * prev sh eval : 0.14ms * new sh eval : 0.22ms * new sh eval opti : 0.14ms