View Full Version : GI + FG Light spill artefact.

01 January 2007, 12:24 PM
A small render issue for you to help me with!

Ive done this render with Mental ray, using Global Illumination, Final Gather, and an ordinary maya light source, the problem is, that light seems to be spilling through the corner (blue arrow) of the ceiling (red) and wall (green), but the wall actualy passes through the ceiling to stop just these problems! The yellow arrows are the light source on the other side of the wall, which is a directional light, specificaly emitting 50000 photons at 1000 photon intnsity, In the render globals, the GI Accuracy was set to 200 and GI Radius was set to 2.

This was just a test render, so some of these setting need to be changed, but how does one get rid of this unwanted light spill?

Thanks, again, in advance!

01 January 2007, 05:42 PM
Model solid thickness into your walls and ceilings.

Preferably you want them thicker than the radius settings for FG and GI, but just getting the normals right in the solid modeled area can remove most of the light leak.

01 January 2007, 08:30 PM
As bgawboy said, you need to fix your walls. That way if the room is a box for instance, just select the box and make an overall extrusion. At least that works for me :).

01 January 2007, 02:53 AM
from the looks of your scene, you could probably just use final gathering with secondary diffuse bounces. Is there any specific reason you need actual photons and GI?

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01 January 2007, 02:53 AM
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