[Radiance-general] Create image with rtrace -n option?

[Greg Ward]

Hi Marija,

In the latest HEAD, I have changed the behavior of rtrace so if -x is anything but 1 and -y is non-zero as well, ray flushing does not take place.  It was really a performance issue rather than an issue with artifacts, however.  You should get acceptable results with the 4.0 release.

I can only suppose that you are seeing lines in  your example because you are not sharing the irradiance cache between processes.  I recommend you add a -af option to do so.  Also, it may indicate that your -ad parameter needs to be a little larger.

I hope this helps.

Best,
-Greg

> From: Marija Velickovic <maricanis at gmail.com>
> Date: October 13, 2010 5:21:52 AM PDT
> 
> Hi,
> 
> I was experimenting with rtrace -n option and I would like to create irradiance image of the building workplane for DF analysis.
> 
> As Greg mentioned on Workshop, rtrace -n doesn't work well with -x option, because after every line values are flushed.
> It means that output image would have lines-like patterns (because no cashing between lines, for various rtrace processes).
> 
> So question is for Greg, but I think answer can be interesting for list users:
> Is there some other way to get proper image with rtrace running in multiple processes.
> 
> For the moment I'm using command line like this:
> rtrace -n 4 -ab 5 -ad 1024 -as 512 -aa 0.1 -av 0 0 0 -ar 300  -h+ -I+ -ov -fac  -x 1024 -y 448  octree.oct < points.txt > image.hdr
> 
> and resulting image has lines-like artifacts.
> 
> Thanks in advance,
> Marija.