Create image with rtrace -n option?

radiance-general
1

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.

2

Hi Marija.

I haven't tried this but you should be able to specify four separate
rtrace processes where each renders a subimage of your workplane.

If you want a perspective view you can use the "-vs" and "-vl"
options to get a continuous perspective.

Regards,
Thomas

···

On Wed, Oct 13, 2010 at 7:21 AM, Marija Velickovic <[email protected]> wrote:

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.

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3

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 <[email protected]>
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.