Hi Remo_G,
I hope I got your question correctly. Please have a look at the scene file and the one minute clip:
Perhaps download the clip for a better viewing experience
https://www.amazon.com/clouddrive/share/jOVZppg6aJObmDQZxqVc1KNaLVm1IQJa2wa6LlAsRkr
The Mat0 uses the sliders and the Mat1 uses a Color Shader to receive the values of the Mat0. The Color Shader is used here for the demo. It should be a linear (float file) that represents the gray value.
A simple gray channel with no gamma should work fine, as in float, but test any gamma based format if it matches the values in the game engine. This is a data file, not really an image file, so it should work. You can compare easily with this set up any image file how it matches the value.
You can create a texture directly in C4D: Go to texture, to the triangle and chose the values you need – “Create New Texture …”
The slider above the texture should be set to 100%, as the value of the texture is multiplied with this value.
Any combination of specific textures and parameters (sliders), as well as the wide variety of today’s Game Engines (besides the two obviously most named Unity and Unreal) creates many possible answers perhaps. I’m not certain if there is a tutorials or even a plug-in (CV-C4D 2 UE4) for your specific needs here on Cineversity.
Let me know if I got your question correctly and if that solves your workflow question.
All the best
