In 2021, I gave a workshop @ STEREOLUX (Nantes - 44 - France) about 3D rendering in Touchdesigner, with advanced buffer techniques.
This knowledge was learned in my past experience, about 10 years in Animation Movies Industry ; we use a lot these render passes to tweak the 3d renders and get the final result.
Here is the Toe file.
NOTES:
On the left : Geometry import / scene setup and 3D render to get buffers
On the center : B2BK custom tools (FastMAT, FastENV, NormMask, PosMask, UVPaint & UVPict)
On the right : Few examples of the use of these tools, to make the teaser image