thank you so much blobbybarack and juanjgon for your answers!!!
i`m aware of the opengl shaders, and it already helps A LOT to use them the way you described...
and also found some more infos in your links.
in fact i was wondering if there is a way to fetch an already mixed Texture or layered Texture of an OCTANE material, as sometimes you have a more complex material which i didn`t manage to use in the opengl parameters,
as i only can load an image OR a channel reference from the vopnet but not the generated texture...
So i was trying to fetch what is declared as NT_TEX_MIX:color or NT_TEX_RGB:color maybe inside the color channels of opengl params?
well probably not... right?
best
jn