🚀 go-pugleaf

OK, finally a question to tax you, cos it's taxing me.

I want to produce a fully stochastic raytracer, integrating across the picture
plane by jittering pixels, across light source areas and across time. These are
the easy bits. I want to integrate across the reflection function, that is I
want to jitter a ray using IMPORTANCE SAMPLING so that it produces a series
of n jittered rays each with a probability of direction proportional to their
associated reflectance value. How do I do this?

All I want is to be able to produce glossy surfaces and an aparrent effect of
'diffuse transparancy' which I take to mean Tupperware. Please note I am not
asking for a package to solve all my worldly problems, provide 3rd world
relief, cure cancer, produce colour overheads and make an entertaining lunchtime
friend.

As I see it, the reflectance function can be a very complex shape roughly
maximum at the reflected rays direction but certainly not symmetrical or even
a volume of rotation. Erk.

Please email me some insights into this problem. It's just another example of
SIGGRAPH papers saying '...which is left as an exercise for the student...'
God I HATE that!!

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- RJGreen.