Warp wrote:
> 
> [...]
> 
> > And finally, pretrace. As I understand it, pretrace is
> > just another pass over the picture in order to check
> > if enough samples are present at any given spot.
> 
>   AFAIK pretrace is simply a preprocessing step to get some initial
> samples in the scene, thus speeding up the actual raytracing.

No, pretrace does not speed up the render, on the contrary it nearly
always slows it down.  Its purpose is to achieve a better distribution of
the radiosity samples taken.  How much this affects the results depends on
the settings.  Just try it out yourself.

In quite a lot of cases it can be efficient not to use pretrace but you
should know what you are doing since it is more likely to cause problems.

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 17 Jun. 2003 _____./\/^>_*_<^\/\.______

Post a reply to this message