This article covers color management options in Corona for Cinema 4D. For general information on color management, see: Color, Color space, and Color Management Basics
Corona and Cinema 4D Color Management
OCIO is supported in Cinema 4D 2023 and 2024 and can be configured in the Project Settings.
Basic color management
The default setting of Color Management for any new document (or document loaded from an older Cinema 4D version) is Basic, meaning OCIO is disabled and color management is handled the same as in previous versions.
In this mode:
- Colors set via the Cinema 4D Color picker (e.g. Base layer color in Corona Physical material) are interpreted as using color profile set by Input Color Profile configured in Project Settings (sRGB by default).
- Colors set in the Corona UI (e.g. Lister dialog) allow setting color either in sRGB or Linear sRGB color space.
- Bitmaps are expected to be stored in sRGB by default, with automatically detected gamma and possibility to override it (e.g. to get linear input for Normal shader).
- Renders in the Picture Viewer and the Corona VFB are shown in sRGB color space.
OCIO color management
Setting Color Management to OpenColorIO will enable OCIO for the whole document.
In this mode:
- The Cinema 4D Color Picker will now allow picking which color space is used by the user for input, allowing to use sRGB as before, but also color in Rendering or Display color space as selected in OCIO configuration.
- Similarly, colors set in the Corona UI (e.g. Lister dialog) now additionally allows setting colors in several color spaces, including sRGB and Render.
- Color profile of bitmaps can be configured when using the standard Cinema 4D Bitmap Shader. This can be used, for example, to use bitmaps stored in one of ACES color profiles.
- Both the Picture Viewer and the Corona VFB will now apply View Transform configured in Project Settings to the rendered image.
More information about OCIO in Cinema 4D can be found in the Cinema 4D OCIO documentation.
Converting existing projects to OCIO
When a document already contains materials, shaders etc, switching color management in Project Settings might not be enough. This is because for basic color management, all colors stored in the Cinema 4D document are saved in sRGB color space by default, however, in OCIO color management colors are stored in Render color space. This means that when an existing document is switched to OCIO, all colors that were previously set in sRGB will now be interpreted either as ACEScg (in ACES preset) or as Linear sRGB (in sRGB preset). To resolve this, Cinema 4D allows you to convert all document colors to proper color space using Convert to OCIO… tool in the Project Settings:
NOTE: The conversion utility in Cinema 4D 2024 has a few limitations:
- It does not support UNDO, so it is recommended to backup the scene before using it.
- It might miss some colors, e.g. Display color in Project Settings is not converted.
Corona limitations (as of Corona 11):
- Corona will internally still use its default Adobe Wide RGB render color space regardless of Render Space configured in Color management. Note that this only affects Corona internals, all color inputs that are selected to use Render color space, both Cinema 4D color pickers and Corona UI, will use correct color space as configured in Color management.
- Corona Bitmap is currently missing the section for selecting OCIO color spaces that are present in the Cinema 4D Bitmap.
- While the Corona VFB does apply the selected View transform to the rendered image, it does not have any quick selector for selecting alternative view transforms that is present in the Cinema 4D Picture Viewer.