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billpayer2005
09-05-2007, 12:14 AM
Hi,
Does anyone know of a solution to the problem of shooting photons from the sun shader into an interior room? (specifically from a midday sun position)

I have diagnosed my photon distribution, and most photons end up hitting the 'roof' of my room, ie. the side of the ceiling that is not visable to my camera. The ceiling is a solid cube geometry.

Is it necessary to turn of photon emission from the sun directional light, and create an spotlight photon only emitter, aimed in another direction ?
That would seem like a weird work around.

Or perhaps emit photons from an area light at the window of the room ?

Thanks !

phix314
09-05-2007, 10:53 AM
Yea I was thinkin about this the other day and, generally speaking, using a directional light emitting photons isn't the best idea considering the distance, so I've always favored the spotlight method. Using an area light might cause some unnatural blooming around the opening.

billpayer2005
09-06-2007, 10:29 PM
Also, the scale and position of the directional light has a HUGE impact on the distribution of photons. Which is not what you might expect from a directional light.

I have found limiting the distribution of photons can help, I think it tries to limit the photons to around the camera. There is a setting in the sun attributes that has a min / max distance setting for photons.

Having a directional light emit photons seems like a counter intuitive idea.

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09-06-2007, 10:29 PM
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