would it be possible to explain in more detail what each does?
the help documentation does not reveal any references other than a redundant explanation.
what are good measures for these? the standard settings are kind of very random since all vallues differ a lot, i assume that these are set to output a general performance to quality relation. but how far can these be set, meaning how far does it make sense at all? any kind of reference for each would be interesting.
thanks!
https://docs.blender.org/manual/en/latest/render/cycles/render_settings/light_paths.html
Diffuse helps with light bouncing about diffuse material properties. Higher means more bounces between surfaces, which in turn essentially means more indirect lighting
Transparent bounces - how many transparent surfaces a ray will travel through until it terminates. If you set it very low you’ll see black spots on glass. If you don’t have transparent surfaces you can turn this down. Transmission is very similar.
Glossy bounces - similar to transparent, except now for shiny surfaces like metals. If you have a huge amount of metal objects you want to crank this up. If you have only a few you could lower the number.
Volume is actually not otherwise exposed in materials, so you can ignore that really.
Maximum bounces is the cap for a ray. So in total a ray will bounce that many times at most.
There should be more posts on this forum showing some different settings for these.
For instance if you are not interested in indirect lighting you could set diffuse bounces to 0 or 1, giving you black, sharp shadows. It will also be faster than doing indirect light bounces.
See for instance Shadow Study Rhino 7 - #2 by nathanletwory .
And like the example images I added for glossy you can do the same for glass materials and transmission/transparent and see how these affect the render results. Diffuse effects are in the linked discourse post.
