[Radiance-general] Re: graphing radiance raytrace paths

[Jelle Feringa // EZCT / Paris]

% ximage someRendering.pic | rtrace -ab 5 -otodLpnsm -h -x 1 -i  
someOct.oct > rays.txt


	Wow, that's getting very close to what I need, thanks very much,
indeed I had problems getting rays to bounce. I'm sorry I never got to
wrestle rtrace before, I was stuck too long with the DTPrad wintel
binaries, I'm glad to have radiance's full power on my disposal now
(thanks Fransesco!)

Also, this will not show all the rays returning to the light sources, 
as this part of the calcuation never gets fully 'traced', the reason 
being that the direct calculation in Radiance attempts to minimize the 
actual number of rays followed to sources as an optimization.  If you 
want to see the paths all the way back to the sources, you'll have to 
get into the rt/source.c file and start modifying the code directly.


	Now that would be computationally perverse to undo that! Hmmmmmmm...
	Since I'm only starting to program (god bless python) that might be
somewhat ambitious ;-)
	Also tracing the rays to the source would be for sake of the image,
there's no numerical ardour to get that done...

Regarding the -s option in xshowtrace, you can go in and change it 
yourself.  The sleep call is on line 260 in px/xshowtrace.c.  
Unfortunately, sleep only takes integer arguments, but you can replace 
it with a call to nanosleep() on most systems.

	Now that sounds like something I could pull off!
	Cheers, thanks a lot!

Jelle.