The correct answer is:

2

In case the impossibility didn't hit you yet, I made a patch for POV-Ray 
which adds a new speed and quality feature to POV's dispersion. It's 
ever-so-creatively called dispersion jitter. Here's the interior{} 
statement I used:

interior
 {
  ior 1.5
  #if (!Photons)
  caustics 1
  #end
  dispersion 1.1
  dispersion_samples 2
  dispersion_jitter 1
 }

I believe the concept of jittering the dispersion samples and my 
implementation are physically realistic and my implementation is compatible 
with photon mapping (see attached image). I plan to make this patch 
(currently a Windows binary) available as soon as possible.

I've attached a higher quality image with dispersion_samples 5 and photons 
and radiosity enabled. This image took a little over 5 hours to render @ 
960x720 +a0.1 +r4 IIRC with a P3 871 under the noticeably slower VC++ 
compile.

Post a reply to this message

Attachments:
Download 'disp-jitter-test.jpg' (62 KB)

Preview of image 'disp-jitter-test.jpg'