Christoph Hormann wrote:
> 
> I already made this scene some time ago but i thought this might be a 
> good occasion to post it since we have just released MegaPOV 1.2.1 which 
> includes the radiosity patches used.
> 
> This image demonstrates the use of the adaptive pretrace and adaptive 
> error_bound patches in a large render of a detailed scene.  One major 
> problem of such renders is that they tend to be very slow at large size 
> since a lot of additional samples are taken in the final pass which also 
> results in a raise of memory use.  The adaptive error_bound gives better 
> control over this - in this case there were only 19 radiosity samples 
> taken in the final pass so you can predict the render time and results 
> much better from a small size test render.
> 
> The adaptive pretrace can reduce the pretrace time in a scene with large 
> areas only requiring very few samples (like the sky here).  However you 
> have to use a low pretrace_start to avoid areas to be completely skipped 
> by the pretrace.  The pretrace time here was 4 hours (final pass time 
> was 13 hours for 6400 x 3600).
> 
> The radiosity settings used are:
> 
>   radiosity {
>     pretrace_start 0.006
>     pretrace_end   0.0015
>     adaptive 1
>     count 100
>     nearest_count 3
>     error_bound { 0.8 adaptive 1.5, 20 }
>     recursion_limit 1
>     low_error_factor 0.2
>     gray_threshold 0.0
>     minimum_reuse 0.015
>     brightness 0.85
>     always_sample off
>   }
> 
> Christoph
> 
> 
> ------------------------------------------------------------------------
> 

It's just that most of your images are fantastic...

Sebastian

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