POVMAN wrote:
> Can anyone tell me in laymans terms what the "pretrace" settings in 
> radiosity does?

The pretrace makes the renderer run across the image area in a coarse 
(and successively finer) pattern and trace the pixels with modified 
radiosity settings (the modifications being low_error_factor and 
always_sample) before doing the actual render.

The pretrace settings adjust what grid stepping is used for the pretrace.

> My recent renderings have not shown any significant 
> differences when changing this value.

The pretrace influences the distribution of radiosity samples.  There 
are a lot of cases where this does not make much visible difference but 
in general the results *always* differ when changing the pretrace 
settings (the difference might be too small to see).

Christoph

-- 
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http://www.imagico.de/ (Last updated 27 May. 2006)
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