I asked:
>> I'm not sure how spotlights are coded, but I would assume they
>> calculate the inner and outer radius and then the intermediate results
>> are calculated with some mathematical function. Can't a similar
>> approach be used for *shadows*? Use the extreme points of the area
>> light to determine maximum and minimum shadowing and apply some
>> mathematical function inbetween, rather than banding it with
>> intermediate lights? (I guess a similar effect could be obtained by
>> using spotlights instead of point lights inside the area light)

Daniel Hulme gently replied:
> But how would a point between full illumination and full darkness know
> how far it is from either? It is easy with spotlights: you just find the
> off-axis angle for the light, and subtract angles. With shadows, you
> don't know what the full shadow and full illumination angles are,
> because they depend on the other objects.

Actually I've been doing some tests and it's even worse; with curved
objects there are points that should be in shadow that aren't ...

So the problem is that the "true" way to do the things would be to
measure the ratio between the area of the area light which is seen by
the point and the total area of the area light, but such areas may be
complex to calculate, right?

Is there a way in POV-Ray to make projections from a point? Maybe it's
possible to design something that does this manually ...

-- 
Giuseppe "Oblomov" Bilotta

Hic manebimus optime

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