Mael wrote:
> 
> > That looks very interesting, i have some troubles understanding how it
> > works though.  The phong model needs the light direction, how do you
> > determine it with radiosity lighting?
> 
> This sampling is independent of the radiosity inter-diffuse stuff. It occurs
> at each intersection point if there is a non zero phong in the finish. An
> adaptive number (calculated with phong_size and a global parameter rad_phong
> (a kind of density)) of rays are shooted near the direction = incident ray
> reflected (samples rays are choosed with an adequate probability density
> function -see the images- that's why it's called importance sampling) and
> light is gathered. Yes that sounds cpu consuming - and it is, but for high
> phong_size the number of samples can be low.

Very clever.

But i guess it is really quite awfully slow.  It could be worth
considering some caching function but that will probably be less helpful
than with diffuse radiosity since the result varies much stronger with
position and surface normal.

How does it look with very low sample counts? Does it look mostly noisy or
are there other artefacts?

Christoph

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