thanks a lot for the reply. So, piping data from rsensor to contrib with
-I+ , makes rcontrib to use measurement point position and direction from
the view file (as expected) but ignores the rays emitted in accordance to
the sensor file. That explains the fact that the results remained more or
less the same when sensor file was replaced. Now comparing the results
(narrow versus cosine corrected sensor, overcast sky) using rsensor/rcontrib
3phase method, without -I+, there is a difference (58%), but it is
much-much less than the difference observed using rsensor only command.
Consequently, calculation of illuminance values with 3phase method can be
done either using the standard method (measurement points to rcontrib with
-I+ ) or with the combination of rsensor (cosine corrected sensor file)
/rcontrib without using -I+ but with some "handling" of the rays emitted in
order to get similar view matrix files.
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Sent: Wednesday, April 30, 2014 10:00 PM
To: [email protected]
Subject: Radiance-general Digest, Vol 122, Issue 33
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1. Re: rsensor/rcontrib (Greg Ward)
Date: Wed, 30 Apr 2014 10:21:38 -0700
From: Greg Ward <[email protected]>
To: Radiance general discussion <[email protected]>
Subject: Re: [Radiance-general] rsensor/rcontrib
Message-ID: <[email protected]>
Content-Type: text/plain; charset=us-ascii
I am puzzled by your use of the -I+ option to rcontrib (first command) and
-i option to rsensor (second command). These options are very different from
each other, and I don't think you really want to use either. The -I+ option
tells rtrace to interpret its 6 input values as virtual illuminance point
and orientation, rather than ray origin and direction as produced by
rsensor. Using the -i option in the second rsensor command tells the
program to evaluate surfaces in your scene as if they were all Lambertian
with 314% reflectance. Again, probably not what you had in mind.
Try taking these options off and seeing what you get. The rest of it looks
OK as far as I can see.
From: Aris Tsangrassoulis <[email protected]>
Subject: [Radiance-general] rsensor/rcontrib
Date: April 29, 2014 9:43:44 AM PDT
trying to compare illuminance values on a single point on the working
surface located in the middle of a south facing room, three methods have
been used (rtrace, rsensor and 3phase method using rsensor|rcontrib to
estimate the view matrix) with the results difference been explainable.
Sensor file represents spatial resonse file of a cosine corrected sensor.
When I have changed the sensor file with one having a narrow filed of view
(2x10 degrees) illuminance value using the 3phase approach was the same (~1%
difference) as in the case of the cosine corrected sensor.
The command was :
rsensor -h -rd 5000 -vf view_test.vf narrow10.dat . |rcontrib -c 5000
-f klems_int.cal -bn Nkbins -b kbinS -m glazing -I+ -ab 11 -ad 50000 -ds .1
-lw 1e-5 test_r.oct>narrow10.vmx
Repeating the calculation with rsensor command only (again narrow versus
cosine corrected sensor file):
rsensor -h -rd 5000 -ab 5 -ad 2500 -ar 300 -aa 0.1 -i -vf view_test.vf
narrow10.dat overcast.oct|rcalc -e
results differ 98%. Any hint would be appreciated.
I've examine the ray directions coming out from rsensor for both the
sensor files and are in accordance with the spatial response. Using NREL's
R4.2.a.4 on Windows.
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