Lightmass ambient occlusion applies to backfaces?

**Tl;dr ** I made a couch with cushions. The cushions make ambient occlusion on the outside of the couch.

I’ve fiddled with some Lightmass settings but I don’t want to end up abandoning my ambient occlusion to avoid some stupid shadows. The cushions on my couch intersect the inside face by a little bit, but I would think Lightmass would ignore the backface of the outside. The side of the couch is also pretty thin, so setting my Occlusion Distance to a puny amount would make the whole AO thing pretty negligible.


I typically don’t like bumping, but I feel like this is an important issue that people might search for.

I’ve experienced this as well. Although in my case I did not use lightmass AO, instead it was the secondary lighting leaking through to the other side of a thin object.

My guess would be that there is some kind of issue with the way lightmass interpolates between samples, but at the time I was not able to find a solution and had to work around it instead. If anyone knows how to solve this, I would be quite interested to know as well.

It’s been almost 2 weeks, but after playing with a lot of lighting settings for different reasons this problem disappeared. I figured I would let future searchers know how I fixed it. Like Arnage said, it wasn’t AO like I thought, but the indirect lighting. I’m not sure what his work-around was, but I ended up decreasing the Static Lighting Level scale to .8 to get more detailed light calculations. I also cranked up the indirect lighting quality to 4, so the Global Illumination is stunning. :cool: I was scared that my geometry was the problem.