[Radiance-general] implementing Radiance reflection model

[Tarik Rahman]

Hi there
I'm still trying to get the correct values for the Radiance reflection model,
they're close but not quite right. So for isotropic reflectance I get K as below


			             [ exp(-tan^2(delta/alpha^2)]
			  K =     -----------------------------------
			         cos(theta_i)*cos(theta_r) *4pi*alpha^2


and use the formula to get the returned colour as
Li = Ii*projected_solid_angle(rho_diffuse/pi + rho_specular*K) where

				cos(theta_i)*PI*r^2
projected_solid_angle =		-------------------								         dist_to_light^2

and r is the radius of my spherical light source.
when I do rview -vf view.vp -av .5 .5 .5 file.oct do I just add this -av value
for ambient light as below?
Li = light.colour*projected_solid_angle*(rho_diffuse/pi +rho_specular*K)
+ ambient;

Thanks for any help

Tarik
--
Tarik Rahman
PhD student, Institue of Perception, Action and Behaviour
School of Informatics
University of Edinburgh