AO bug/error

[Eddoron]

Here's my replication.
low vs high sub-division.
phong(pretty much any angle) vs none.
native c4d ao shader
edit: saved out the wrong file for opensubdiv. just lower the subdivision and change it and it becomes visible.
also happens with boole'd geometry.

 

[houska]

I don't know, man. I looked at your scene and it looks weird indeed, but I could not get C4D AO to look good either... Let's ask Tom Grimes, what he thinks...

[Eddoron]

The C4D shader isn't the best option either but it was the quickest example.

But hey, at least it's not SSAO.

I also noticed a difference between IR(left) and Final.(right)

Terrifying but which is da wei?

[TomG]

Sorry, didn't have time to look into this yesterday. That turned out to be potentially useful, as I did notice a difference with an SDS object in IR and offline rendering while working on other stuff, and it may be related.

I was using the free scene from Yarko Kushta / Studio Heisenberg at https://www.patreon.com/posts/free-scene-for-8459185 and with an offline render, I get artifacts on the curtain, but not in IR (image of the artifacts attached). No AO used here, but definitely something different with SDS in IR vs offline.

[TomG]

As well as similar results from native AO in C4D, the same thing also happens in Max.

Solutions that I can see for now are - the object is very small in scale, larger scales seem to work better; and of course raise the number of Subdivisions :)