Hi Micha,

> My first guess is that POV-Ray always uses the same light direction
(namely
> the vector from lightsource "main" location to the hitpoint) for the
> calculation of the lighting (diffuse, phong, etc.). Or it does this
> calculation only once (with a light source intensity calculated from all
> the shadow rays shot for each sub-light of the area_light). This would
> explain pritty much all of your effects.

That might be it - however, without looking at the source code, I guess I
won't know for sure. I'm kinda busy with work and getting ready for college
in a few weeks at the moment, so hopefully I'll get a chance to look through
it soon.

>Also, if the light source is
> relativly far away from the illuminated objects it will not make a big
> difference as the vector only changes a bit.

Agreed. However in my test scenes, the lights were only a few units away
from the objects at most, so they should have recieved plenty of
illumination. The Povray arealight seemed to leave the sides of the spheres
in the dark, even with very long lights (see the extra 'cat's-eye' test near
the bottom).


John

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