> Sorry I don't get it... Is it possible to make POV emit light from more
> than a single infinite small point?

> "Area lights" in POV are nice but they only affect shadows, and not the
> light itself.

There's been some confusion on this subject and tinkering with the code I
found something interesting.  An area light does emit light from the entire
area.  What's important is how to define light.  What it does is test if the
point is lit or shaded for every area on the surface of the area light.  It
takes all the resulting light colors and shadow colors, without any surface
shading, and averages them together.  The important detail here is that no
shading is done.

Lambertian shading (diffuse) models the falloff of light as a cos of the
incident angle of the light.  This assumes that most of the light is coming
from the same general direction.  I don't think the same rules apply to a
light covering a large area.  Furthermore, phong and specular are light
tricks that mimic the spreading of a reflection of a pointlight by the
roughness of a surface.  Making the highlight larger would probably be all
that is needed (or using reflection of the surface with a high exponent).

Anyway, after performing the area light calculations, you have a softly lit
representation of the scene without any finish.  The problem I ran into is
that when POV does the diffuse calculation it only uses the center of the
light and renders self shadowing black - it also causes the edges of the
diffuse 'highlight' to render black.  This pretty much kills all the soft
lighting effects from the area light.  So I just skipped that part when
doing the patch area light.   :)

It's not perfect but I think it's a step in the right direction.

-Mike

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