/ light

ltview: a Radiance utility

Update/note: This utility has been through a few changes. It currently exists as a Perl script written by Axel Jacobs, and is part of the Radiance source code. Get some!

/rpg, April 18, 2014


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 Ward’s objview script and modified it to take a single Radiance 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. All the other options in objview are available in ltview. (it's even better, now).

ltview is useful for making sure the distribution of your light source is what you think it is, and that nothing went awry during the ies2rad conversion. It’s also good for checking replmarks triangle orientations.

(Updated April 18, 2014)