I have created scene with more than 16000 instances of sphere_sweep
(catmul_rom, 9 spheres for each). I have tested this image with cones - it
took no more then 3 minutes to render on PII 233. I have started sphere_sweep
version on P4 1GHz (2 proc). Parsing/bounding/vista/light initialization was
no longer then 5 minutes. No other long tasks on this computer. Sphere sweeps
are evenly distributed over whole image so I suppose each line should take the
same amount of time. But after first day I found at beginig of output stream:

  -:--:-- Rendering line    0 of  600 supersampled 38 times.       
  9:40:17 Rendering line    1 of  600 supersampled 64 times.       
 10:29:44 Rendering line    2 of  600 supersampled 41 times.       
 11:11:45 Rendering line    3 of  600 supersampled 15 times.       
 11:46:41 Rendering line    4 of  600 supersampled 13 times.       
 12:21:07 Rendering line    5 of  600 supersampled 8 times.       
 12:54:12 Rendering line    6 of  600 supersampled 7 times.       
 13:15:59 Rendering line    7 of  600 supersampled 9 times.       
 13:32:42 Rendering line    8 of  600 supersampled 17 times.       
 13:50:26 Rendering line    9 of  600 supersampled 15 times.       
 14:07:57 Rendering line   10 of  600 supersampled 8 times.       
...

Any idea why first line took so much time ? Is there so much to initialize ?
I know it is hard to say without sources but it is possible I use it for
shortest code contest. I wait with publication and want ask first if it is
known problem (of course I know sphere sweeps are slow in nature).

ABX

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