Doing this in Cycles is not easy and was never really intended to be a thing. If you are trying to get realism, AO is not needed in Cycles.
In Cycles, there is little focus put on ambient occlusion, because Cycles has full realistic bounce light, which is considered better than AO. Basically, AO is a cheap replacement that realtime renderers use to fake what Cycles does by default.
If you really want AO in Cycles, you will find a section called “fast GI approximation” in the render settings. This feature allows light rays to be replaced with AO after a certain number of bounces and will give you an AO tinted with the world color.
However, if you want more control, you will need to do it in each material one by one.
can´t believe that i´m the only one that misses the global ao feature. maybe all the rest composes.
for me it looks better with a bit of AO everywhere in the edges… it is possible to see that after compositing AO renderlayer in… afterwards…
Vray is an old renderer. If I understand correctly, it has gone through multiple rendering methods. Depending on when and how you used it, it’s possible AO was in fact needed to replace missing details in the bounce light.
However, if you used it recently, maybe you didn’t really need the AO. Your Cycles image here is actually realistic, if you compare it with real life (it looks fake mostly because it lacks textures). You can see an AO effect naturally happening in the shadow, while the side of objects in the direct light looks mostly flat. This is actually realistic and how it happens in real life. AO is the shadowing of ambient light and doesn’t affect direct light.
It might look better and “more 3D” if you put a full occlusion pass over your render, but if you start looking at objects in real life, you will realize the AO is really only visible in the shadows and only affects the soft ambient light.
thanks jonathan for your time and work,
…as i said in the initial post, i did not want to compose. i knew that it is possible to edit every material or to do it in compositing. but i wanted to get it directly rendered in.