Unwanted Light Spots when using Final Gather

Anoif

I've been working on lighting this scene in Maya using mental ray. There are weird light spots that are showing up under the window sill and on the right wall near the floor. It only shows up when final gather is on. I tried turning up all the settings under Final Gather, Caustics, and Global Illumination. Some of them would improve the spots, making them smaller and dimmer but they would get to a point where it would no longer improve. For example, I would turn Caustics Accuracy from 100 to 1000 and see an improvement. Then I would change it to 10000 and seen no change at all. I did this with each setting that has a numerical value in the Final Gather, Caustics, and Global Illumination sections of the render settings. Please help me if you know anything about this.

nezach

That kinda looks like a light leak. Samples from the lit side of the wall could be showing up on the dark side. You could try to make the geometry solid so it won't collect from the other side through the cracks. Or you could try to dial down the sample radius to lower than the thickness of the walls and see what happens.

If you go for the second I would turn off all the indirect stuff and then render turning one system on at a time to see if you can isolate which one is causing issues. That way you know which one to dial down, rather than randomly adjusting stuff and crossing yer fingers.

Anoif

I tried both solutions. I haven't dealt with the textures yet because I wanted to make sure it worked. The walls, floor, and window sill are all 1 object. I hope by sample radius you meant sample level min and sample level max (that's what maya support referred me to). I changed both a few times and had the best results with min:0 and max:1(was 0 and 2). It definitely helped a lot. It's almost invisible under the window sill, but it's still there on the wall on the right.