The default color manager implements the open-source OpenColorIO (OCIO) color management system and uses an OCIO v2 config shipped with Arnold. The color manager is configured to leverage the industry standard ACES color encoding system, setting the rendering color space to ACEScg.
Viewer devices (e.g. monitor, TV screen, etc.) have limited dynamic range and color gamut. To display the rendered image properly on these devices, it has to be transformed to the viewing color space (usually Rec 709 for TV and sRGB for web).
Besides the color transform, the image can also be tone mapped. Arnold uses the ACES 1.0 SDR-video view transform by default which offers filmic tone mapping.
When rendering to the Picture Viewer or in Commandline or Team Viewer, Cinema 4D applies its native sRGB color transform, expecting the output to be in linear color space with sRGB primaries. That's not the case in Arnold when using a custom color manager (e.g. an ACES workflow with a custom view transform).
To get the correct output, this flag has to be set based on the image format we are targeting:
This built-in color manager (the default color manager in Arnold 6) supports two color spaces:
This color manager is equivalent to the native color management in Cinema 4D.
The color spaces are grouped by the families defined in the config file.
This is the default color space used on linear input textures which uses sRGB primaries. Typically HDR (high dynamic range) images, e.g. skydome or area light textures.