[Radiance-general] Slow spawning of rtrace -n, mkillum -n with many light sources

[Axel Jacobs]

Dear list,

I'm running some rtrace -n xx calculations, and noticed that there is
only one thread for 30 to 45 minutes, before the -n xx kicks in.  My
scene contains some 6,000 artificial light sources.

The question I have is this:  Is there something within rtrace/mkillum
that is not multi-threaded that is run before the actual ray tracing
part starts (which does honour the -n option)?  I could think of some
light source visibility or intensity test that need to be done before
the actual ray tracing.

Many thanks for your thoughts

Best regards

Axel