Radiance User: "Boy, that objview script sure is handy for looking at scene geometry; if only there was something like that for looking at the distribution of my light source files."
Announcer: "Well, THE WAIT IS OVER!! That's right, now there's a script that has the ease of use of objview, but is scientifically engineered for use with Radiance light source input files! Plus, if you call now, we'll include K-Tel's "70's platinum hits" -- on eight-track -- absolutely free! Don't delay, limited offer, operators are standing by, yadda-yadda-yadda."
Ahem, sorry. In all seriousness, I took Greg's objview script and modified it to take a single scene input file and place it at 0,0,0, then surround it on five sides (top, bottom, E, N, W) with opaque surfaces. It sets -ab 1 and -ds .15 and then loads rvu with a view looking into the box. The box is 48 units square by default; you can change the size of the box with the -bs switch (and no, there isn't a -bs- option for my posts, sorry). All the other options in objview are available in ltview.
ltview is useful for making sure the distribution is what you think it is, and that nothing went awry during the ies2rad conversion (also good for checking replmarks triangle orientations, Lars). Anyone who wants a copy just ask and I'll email it to ya.
···
----
Rob Guglielmetti
e. [email protected]
w. www.rumblestrip.org
Hi Rob
I've tried ltview with this luminaire (lumen output is prob. wrong, but it doesn't matter):
erco.rad:
···
--
void brightdata erco_dist
4 flatcorr erco.dat source.cal src_theta
0
3 100 0.035 0.0005
erco_dist light erco_light
0
3 1 1 1
erco_light ring erco.d
0
8
0 0 -0.00025
0 0 -1
0 0.0175
erco_light ring erco.u
0
8
0 0 0.00025
0 0 1
0 0.0175
--
erco.dat:
--
1
0 180 37
3.91061 3.6933 3.25531 2.61173
1.80559 0.368156 0.157542 0.0374302
0.0145251 0 0 0
0 0 0 0
0
--
The lamp is correctly positioned in the middle of the room, but the box looks just grey. No light/shadow is cast by the luminaire. Setting it to 10 (metric) units doesn't help.
If I use
room.rad:
--
void plastic box_mat
0
5 .5 .5 .5 0 0
!genbox box_mat box 10 10 10 | xform -t -5 -5 -5
--
with this view file:
--
rview -vtv -vp 10 0 0 -vd -1 0 0 -vu 0 0 1 -vh 90 -vv 90 -vo 5.5 -va 0 -vs 0 -vl 0
--
(clip front surface), it works hunky dory: splotch on the floor!
I can't see which one of the default rvu parameters causes this. Could be one of the -a* or -d*, but I am not sure...
My feeling is that -av should be set to zero. The lamp might be very dim, in which case it's washed out with the ambient. Is it really necessary to involve rad? this is done in objview, because you don't know upfront how big the scene is etc.
Cheers
Axel
Axel Jacobs wrote:
Hi Rob
I've tried ltview with this luminaire ... <snip>
I can't see which one of the default rvu parameters causes this. Could be one of the -a* or -d*, but I am not sure...
My feeling is that -av should be set to zero. The lamp might be very dim, in which case it's washed out with the ambient. Is it really necessary to involve rad? this is done in objview, because you don't know upfront how big the scene is etc.
Hi Axel,
Hmm. The only parameters I change in the script are -ab (1 from 0) and -ds (.15 from 0). I suppose rad is making some other changes? The reason I'm using rad is because with the addition of the -bs option the script also dosen't know how big the scene is. I suppose I could change it to set up a default view like you have, and scale the -vp if the user enters a different value for -bs. I was trying to change as little of objview as possible though. Anyone who's seen any of my programming knows why. =8-)
I set -ab 1 because the scene just looks better, the bounce reveals fixture geometry and glow sources; I thought by scaling the room with -bs you could always have the light source close to the room surfaces, minimizing the ambient washout problems.
Your erco source file shows a tiny ring (radius of .0175), but your room/box is 10 units square (in your example). Did you maybe assume meters for one thing and milimeters for the other? I did "ltview -bs .2 erco.rad" and it looked fine (and there is approx. 1730 Lux under the fixutre, .1 units away). I can't read an ies2rad -> rad file and spot errors easily (hence this ltview utility), but I suspect maybe there's a units mismatch. That doesn't explain why your test scene at 10 units square looks OK, though. Hmmm.
Could you double-check your ies2rad input?
···
----
Rob Guglielmetti
e. [email protected]
w. www.rumblestrip.org