[Radiance-general] experiences with the photon map

[Lars O. Grobe]

> I think you are right. Anyhow, I'm not sure, if Roland implemented the
> correct pmap conform rpict-call within findglare - I'm pretty sure he
> never worked on that. Therefore there is no other way as rendering the
> whole hemisphere and than evaluating the picture.
Help!!! I do not get it... to get the illuminance from a 180 degree 
fisheye picture (no matter if taken by a camera or rendered by rpict), I 
have to integrate the luminance values over the circular surface of the 
projected hemisphere. This means that I somehow have to sum-up the pixel 
values. Still I do not really know the maths to do it, can anyone give 
me a hint, please? Is it the average of the pixel values multiplied by 
the surface area, the  pixel values being weighted according to the 
solid angles they cover?

CU Lars.