Light bleed 3DS Max - Mental Ray

#1

I come across this every time I try and create architectural interiors and I can never work out why. My interior space is completely enclosed and solid (I have a material override on in the render setup), yet I still get light leaking through the corners of my room. I have a lighting setup using MR Daylight and a skylight. Here is a screenshot of a test render (which I would have thought would be completely black as there should be nowhere light can enter from the outside) and a screenshot of how my floor and ceiling intersect with my wall

light bleed render.jpg

light bleed screenshot.jpg

Does anyone know what causes this light bleed and how I might prevent it?

Thanks
James

#2

Seems to be combination of photon radius settings and your walls, which seem to be unrealistically thin. Try making the outer walls thicker. If you want to leave the walls as they are, you would probably have to adjust the sampling radius to be about the same as the thickness of your walls.

#3

That’s great! Thank you for that - i’ve had to make my walls crazily thick but it’s worked a treat

Thanks
James

#4

You shouldn’t need to do this at all. Are you not using FinalGather as well? I never create any thickness at all to my walls, except structurally, but exterior walls are always a singly poly face in thickness. Only with glass windows which border an outside scene/backdrop would you need actual two-faced opposing thickness. Perhaps your Normals are not aligned?

#5

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