yafray: artifacts with area lights

any yafray-cracks around?
Now that blender has a build in yafray function even a lazy guy like me can try out rendering with yafray. My first try is not satisfactory though.
http://home.arcor.de/ulf.lorenz/yaf1.jpg
Besides the redish lamp in the right I placed blueish area lights outside the windows (that don’t have panes). The lights have exact the shape of the windows. While the light inside the room behaves allright it casts strange artifacts at the window frame. Any idea why? Here are my settings:
http://home.arcor.de/ulf.lorenz/yafshot1.jpghttp://home.arcor.de/ulf.lorenz/yafshot2.jpg
thanks, ulli

Hm, not so many yafray experts around it seems. Meanwhile I have the artefacts under control by setting the lights farther back outside. But instead I have these eluminating parts on the window frame. All frame parts are the same material. This is even more enoying since the rest of the pic looks real good to me. :frowning:
http://home.arcor.de/ulf.lorenz/yaf4.jpg

ulli

Is the emit value of these windowframes set to zero?

Is the emit value of these windowframes set to zero?

yes it is. it looks like emitting light but it isn’t. the brighter the light from outside the worse this error…

ulli

I’ve had some weird issues too w/ Yafray doing weird stuff. It seems when dealing with things that are both reflective and refractive, it creates extra light. i.e. in reality when a ray of light hits glass, part is reflected, and part is refracted. However it seems the same amount must go both ways (maybe I need to play w/ the fresnel effect stuff). Try setting the CDepth to zero maybe? I was playing around w/ caustics recently and rendered this:

http://astro.scu.edu/~ted/3d/causticstest01mini.jpg

For some reason, my area lights disappear when I turn off “tune photons”. So this scene has effectively no real light source. Yet, the box with the water is glowing. I think this is because the light gets reflected and refracted the same amount. Since the same amount is going both ways, the light in that area gets amplified. The same applies for the apparent glow underneath the wine glass. I may be wrong in my theory regarding the cause, but something deffinately is askew with GI and transparent objects.

So, my guess is the brightness by your windows is due to the windows themselves generating light. Could you maybe move the camera to focus on the window pain area?