Yeager wrote:
> Hi!!
> 
> I'm a new user of POV. I looked your FAQ but I didn't find answers to my
> problem.
> 
> I need to model a cornell box with photon mapping. I used different scenes
> gave with pov to do it.
> 
> However, my photons in the scene are not always shot and when they are shot,
> they don't give good results of global illumination. I don't see any
> difference between basic ray tracing and photon mapping?

POV-Ray uses photon mapping for calculating caustics but not for global 
illumination.  In other words - photons in POV-Ray only take into 
account the specular but not the diffuse light transport.  This is 
explained in detail in Wann Jensen's work and Nathan's paper on the 
POV-Ray photon patch (you can find it at 
http://nathan.kopp.com/photons.htm).  In fact photons can't be used 
efficiently for global illumination directly, you can just use them for 
speeding up other global illumination techniques.

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 23 Sep. 2004 _____./\/^>_*_<^\/\.______

Post a reply to this message