Arnold has three global settings for linearizing input data by applying an inverse-gamma correction. By default, texture maps, light colors, and shader colors are assumed to be already linear, but if you need to linearize them, set the gammas to 2.2.
C:\solidangle\Arnold-188.8.131.52\bin>kick -info options | find "gamma" FLOAT texture_gamma 1 FLOAT light_gamma 1 FLOAT shader_gamma 1
- The texture_gamma applies only to non-floating point textures. Floating point (Half, Float) textures are assumed linear.
- Texture maps used to control things like normals, displacement, and opacity, will also be linearized if you set texture_gamma to 2.2.
- The light and shader gammas apply to colors picked from color swatches in the application UI (that is, color ports that don’t have a shader tree plugged into them).
In plugins like SItoA and MtoA, you can find these gamma settings in the global render options.