AO question

[miacreed]

Hi all- hope everyone is well.

I'm attaching a render made by an Argentinian studio. I'm aware that they use Corona. I'm wondering how they created this irregularity on the edges of the concrete slabs on the ceiling (outlined by me in green). I suspect that it was done with an AO map? Perhaps using Maps rather than colors? Anyway, I'm a little lost and was wondering if anyone had any leads as to how this is achieved. Thanks in advance!
Best
Mia

[Beanzvision]

Hi, I'm a C4D user but you should easily be able to do this in Max :)

[miacreed]

Hi, yes! That's precisely what I would like to recreate.

I don't know what I'm doing wrong. I might not be interpreting your screenshot properly- I'm not familiar with the C4D interphase. The occluded color (I made it red as to see it better), looks as if it's evenly being distributed along the edge of the objects, but I'd like it to have a sort of irregular shape, as yours does... am I missing a map here?
Thank you so much :)
 

[romullus]

You're on the right track, just need to tweak some parameters here and there and it should work as you need. Try to increase AO color spread to boost AO effect. Sometimes ray directionality might help as well, don't be afraid to try it as well. Lastly if you want more pronounced unevenness of the seams, you can increase contrast of noise map used as AO max distance. You can do this either by clamping high and low noise threshold in noise map, or by introducing new Corona color correction node and increasing contrast there.

[miacreed]

Ok perfect! It's working now.

Thanks for the help!!!

Best
Mia

[romullus]

You're welcome!