Hi Ali,
I agree that this is an interesting and unexpected result. I've looked
over the code, and I suspect the cause is having so many ambient samples
for a small starting radiance is causing the ambient super-sampling code to
hit the 1e-7 (FTINY) threshold for ignoring differences between adjacent
ambient divisions.
What happens to your series when you use -as 0. I would expect the errors
to go up for all brightnesses, but hopefully you will at least get the same
errors for all gensky -b settings at that point. This would confirm my
suspicion, and allow me to implement a fix.
Cheers,
-Greg
*From: *Christopher Rush <[email protected]>
*Date: *April 21, 2017 7:46:08 AM PDT
I don’t think I’ll have the answer to your question, but to be sure we all
understand… although you get more consistent values between –b 10, 100, and
1000, when you increase –ad they all converge toward the trend you would
expect from –b 1?
-Chris
*From:* Ali Fatoorechi [mailto:[email protected]]
*Sent:* Friday, April 21, 2017 10:15 AM
Yes the posted figures are sort of avg of multiple runs.
I noticed for -b 10, 100,... options the -ad has to be increased to some
x4 more to get same accuracy as -b 1.
But I am not sure if this is expected in Radiance.
Regards,
Ali Fatoorechi
MBS Survey Software Ltd
On Fri, Apr 21, 2017 at 2:38 PM, Christopher Rush < > [email protected]> wrote:
Ali,
If you run the same commands multiple times, do you always get similar
results? Does -b 1 always give proportionally 2% higher value than the
higher orders of magnitude if you repeat the process multiple times, or
does it vary?
If you change the –ad or –lw parameters do you get any different degree of
consistency?
-Chris
*From:* Ali Fatoorechi [mailto:[email protected]]
*Sent:* Friday, April 21, 2017 7:57 AM
Hello guys,
I am a bit struggling to make sense of numbers I get. I might have done
something wrong.
The rtrace gives roughly same irradiance figures(apart from the exponent
component) for overcast sky generated with -b 10, -b 100, -b 1000,
or any other power of 10, while -b 1 gives slightly higher value.
rtrace -w -h -I -ab 12 -ad 10000 0 -as 4096 -aa 0 -ar 0 -lw 1E-05 room.oct
< pnt.txt
!gensky 3 21 10 -c -a 51 -o 0 -m 0 -b 1
-b 1: 9.245390e-002 9.245390e-002 9.245390e-002
-b 10: 9.045287e-001 9.045287e-001 9.045287e-001
-b 100: 9.023538e+000 9.023538e+000 9.023538e+000
-b 1000: 9.039278e+001 9.039278e+001 9.039278e+001
This is a simple room with an opening and no glazing.
Thanks,
Ali
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It gives ~same results with -as 0 for all -b