Hi @seth_richardson I’ll try to answer as extensively as I can.
3: When working in a sRGB/Linear Workflow what is the correct setup for Vray 6.1?
I’ll start with a brief explanation of the state of working in sRGB/Linear Workflow as this is mostly applicable for older versions of Cinema 4D (R26 and older).
Disabling the “Linear Workflow” is not really supported, as V-Ray always uses Linear sRGB or ACEScg as a render color space internally.
The “Input Color Profile” option basically determines the color transformation that will be performed on classic material****s and shader color inputs. When this option is “sRGB”, an sRGB → Linear transformation is performed, when it is “Linear” no transformation is performed on the colors. Note that this does not affect the node materials which are always storing and using linear values, but the color inputs there allow the values to be previewed either as linear or as sRGB, by this button in the expanded control:
So having covered the inputs, the color management in the V-Ray render settings only determines the render color space that is going to be used, but it is important to note that even if ACEScg is selected, the color inputs in the classic materials and shaders are considered in the color space determined by the “Input Color Profile”.
1: When working in a ACES workflow what is the correct setup for Vray 6.1? I am assuming it is setting C4D Project settings to OCIO ACES.
It depends on your version of Cinema 4D. If you are using older Cinema 4D version (R26 and older) there is no much choice - there is only the “Basic” color management.
For 2023 it depends on whether you are starting a new project or trying to convert an existing one. You can of course still use the “Basic” color management,but you will have to take into account the difference in input color values that I wrote before.
If “OpenColorIO” color management is used, you should note that you should always use the “Convert to OCIO…” button (even for new scenes), andin order to preserve render result for existing scenes, it is important to use the following color spaces when converting:
Note that using the “OpenColorIO” color management without converting the scene leaves it with the basic color inputs, but tries to use the OpenColorIO management for rendering which makes matching previous render result impossible to match.
You should also note that using the “OpenColorIO” will
disable the “Color Management” option in the V-Ray settings, because the option will now be used from the OpenColorIO tab in the project settings (more details below).
So after the scene is converted, all color inputs in the scene (both in classic materials and shaders, as well as in node materials) will have the buttons in the color details to choose the exact color space in which to view the value of the color (left in the screenshot below).
While the render space used will be determined by the “Render Space” option in the document color management (right on the screenshot above) or simply use the “Preset” drop-down above. You should just note that currently V-Ray supports only the “ACEScg” and “scene-linear Rec.709-sRGB” as render color space.
2: When working in a AGX workflow what is the correct setup for Vray 6.1, mainly around color swatch issues?
About AGX - it is only a display transformation so it does not have direct relation to the actual rendering color space or inputs.
I hope this more or less answers your questions about how to use the color management with V-Ray.
We were interested in setting up the aces color management in c4d o that we could use the color picker to make matching brand colours for product visualization easier. For redshift this is an easier thing because if you switch the color picker to “Display” mode. It reverses the color management and it tris to match the colours to acescg. This is all well and good but with vray this doesn’t seam to work.