External Light bleed with Path Trace JJ04

Al/Rich

Noticed this on Kitchen render.

When walls and ceilings are perpendicular (flat box shape) to each other no problem, when ceiling is sloped (wedge) ie not @90 then you get light bleed from outside.
Image below

EDIT delete next post and added by invisible tool bar

Attached skp test light bleed.skp

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Permalink Reply by Boothy on October 6, 2010 at 8:54am

Is the top of the box (ceiling) a separate group \component to the walls ? I only ask because I sometimes find that the standard renderer can sometimes have bleed from sun if the componenets are not overlapped.

Boothy

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Permalink Reply by Richcat on October 6, 2010 at 8:58am

No group or component to walls ceiling, but I'll try over lapping the top plane of the box see if that works.

EDIT extended top box plane but there is still an edge still there and renders with light bleed again

EDIT Its appears not be edges or edge lines (I drew some in example below) but where planes meet at angles

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Permalink Reply by Render Plus on October 6, 2010 at 12:47pm

Are there 3 planes on the ceiling, but only one for each wall?

EDIT: Is this in path tracer, or both?

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Permalink Reply by Richcat on October 6, 2010 at 1:16pm

Yes 3 planes as I divided it up to see if it was the edge/lines causing the problem an single for walls, Model attached above before splitting planes, which they appear not to. Thinking about it I'll try 3 planes to ceiling at different angles - report back later.

The above images are both path tracer last one with render edges lines , below packet method which shows less bleeding but its there

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Permalink Reply by Render Plus on October 6, 2010 at 1:34pm

Here is the same model without lights, with PT:

And here it is with Packet mode:

I will point Roy to this thread, but I think the answer, if you want to avoid bleeding entirely is to make the ceiling and walls thick. All rendering is done in single precision math, and some errors in calculations of intersections will always be possible.