[Radiance-general] Getting number of pixels for fisheye view

[Lars O. Grobe]

Hi list,

to be able to integrate the luminance values of a fisheye view, I need 
the number of pixels in the image that are part of the view. I can take 
all pixels which have not a value of exactly 0 (as this should never 
exist for a valid material), but this seams to be not very accurate. I 
know that I can test if a pixel is inside the field of view using pcomb, 
which defines S(n) as zero for pixels outside the view, but I do not 
know how to access this value to count pixels inside the view. At the 
moment, the easiest way for me would be to render a fisheye pointing 
towards a 180 degree source without any geometry and count all 
none-black pixels, but I am sure that there must be a better way to test 
for the pixels' validity.

CU Lars.