Sanity Testing BSDFs


When simulating light transport with light-backwards raytracing, complex macro- or micro-geometry that obfuscates light sources -- especially a small, intense light source such as the sun -- generally cause the alrogithm to break down, leading to gross error. In other words, when doing a lighting calculation, nasty bits at the window can cause the calculation program to take a shit. In recent years, the Radiance lighting simulation system has been adapted to support lighting simulation of complex fenestration systems (a.k.a. nasty bits at the window), by way of the so-called Radiance Three Phase Method. At work, my co-workers and I are integrating this simulation method into OpenStudio, to allow designers and engineers to more accurately simulate the effects…

Continue Reading

Published


So, last month, I presented a paper at SimBuild 2010. Today, the lab I work for published a link to the preprint, which enters me into the scientific roll call. I am stoked. Check it out: http://www.nrel.gov/docs/fy10osti/47522.pdf…

Continue Reading

Radio Radiance


Last Thursday, I hit the airwaves, yakking about lighting simulation. For some reason the Boulder Green Building Guild was interested in my take on the use of simulation in optimizing the energy efficiency of building designs in the US, on the latest installment of Footprint Radio. It was a thrill to share the half-hour with Kostas Papamichael from the California Lighting Technology Center, and my buddy Mike Plann from Lightlouver. I hope one or two people listen, and are intrigued enough to explore daylighting design, or at least turn off the lights once in a while. The cool thing is I'm now in the iTunes Music Store. Check it out by listening to the show on the BGBG's website, or…

Continue Reading

Update


Still alive. Brenda saw her third production season at the Colorado Shakespeare Festival to fruition; all shows are up and running, her crew gets tighter every year and she seems to like it more all the time. Riding my bike again; still outta shape. The four eggs nesting in our hanging plant out front have hatched; got a couple of crappy pictures, lack motivation to get them off the camera. Hooper weighs 58 pounds, a 16% increase from past vet visits; still considered normal, but he could stand to lose a few lubs, just like his owner. The goddamned TV is busted, on the final week of the Tour; parts on order, will arrive after the Tour. In one week…

Continue Reading

I don't get it.


Once again, I have had a humbling experience working with Radiance. Just when you think you know even a little bit about this program, you are told otherwise, simply by attempting to learn more about it. Details here: initial results with rtrace's multiprocessing feature 9QM93TAVDT59…

Continue Reading

Blast from the Past


(light transport simulation geekery alert) Freshly inspired from the recent Radiance Workshop, and cooped up under 22 inches of snow in Boulder, yesterday I took an old web page I created and integrated it into my website. It's a summary of my first foray into the use of illums on a project. This page dates back to 2003; I've been told it's helpful, so I thought I'd get it back online with all my other crap. Here's the link: http://www.rumblestrip.org/interests/light/using-the-illum-material-for-smoother-renderings-in-radiance/ Happy rendering.…

Continue Reading

Lettin' the Cat Outta the Bag


I know, it's been a while. Here's the thing: I got a new job! After almost four years at the firm I work for, I am moving on to a new job, in a new town. It's still a lighting/daylighting/sustainable design job, but it's in an entirely different setting for me: a national laboratory. To say I'm excited understates things a smidge. In a few weeks, I (and my co-worker) will be the new resident daylighting "experts" at the National Renewable Energy Laboratory, down the road in Golden, CO. I'll be applying my skills as a lighting designer and simulator, hopefully assisting research aimed at helping us bring light into buildings in more sustainable and useful ways. I'm…

Continue Reading

Speedy


3421 seconds. That's how long it took my new laptop to render the de facto radiance benchmark scene. That's good enough for 13th place on the list, not bad for a laptop marketed to college kiddies and soccer moms. My old laptop is 36% slower in this test, and cost me $700 more than my new one. Amazing. Full stats: rpict user time: 3421 proc: Intel Core 2 Duo cores: 1/2 clock speed: 2.4 GHz cache: 3 MB OS: OS X 10.5.6 Radiance ver: 4.0a compiler: gcc 4.0.1 compile options: -O2 -ffast-math -funroll-loops results: 691120680 rays date: 2008-12-29 submitter: robg…

Continue Reading

Lumen Awarded


A former co-worker just IM'ed me to let me know that a project I worked on has received two Lumen Awards for exemplary lighting/daylighting design. I am pretty psyched, since to date these are my first two Lumens in my 15 year career in lighting. Awards are stupid, until you win one. Yay! Looking back, it's interesting because this was the project that finally got me to get over the learning curve of Radiance, as the tools I had been using were simply not up to the job of simulating the daylight and electric lighting in this complex space. This project forced me to learn Radiance, made me jump back to the Apple Macintosh world (because of OSX's superior…

Continue Reading

Good and Bad


Well, it's been a few days now, and I have good news and bad news about the new MacBook Pro. First off, it's fast; much faster than my old Powerbook, but then again my old Powerbook is four years old and that's not a fair comparison. Regardless, I'm pleased as hell with the speed, and recently ran a Radiance benchmark test on it and the MacBook Pro proved its mettle. But some other niggly details are pissing me off and ringing in my ears (literally) and I feel the need to vent. Where the hell did tabbed browsing go? I'm using Safari once again because it's a Universal Binary, and I'm trying to simplify my life so I thought running…

Continue Reading

Dualin' part Deux


The other day, I was gushing on this site about my newfound access to a dual processor linux machine. But now, after yesterday's announcement at Macworld, I have ordered one of the new Apple laptops, which will sport a dual core Intel cpu. Come February (hopefully), I'll have a personal computer that's about eight times faster than my current one, at a cost about $300 cheaper than the last Powerbook I bought four years ago. Unbelievable. I know I'm in for some version 1.0 blues, as new hardware and software always have some "issues", but I'm looking forward to being able to run Radiance simulations on my lap, try out the new Tiger features ( I'm still on OS X…

Continue Reading

Dualin'


It's sad, but this excites me: Today I got access to a dual processor Radiance machine, and finally got to try out a newish feature of rpict, the -N switch. Using this option, rpict will send multiple renderings to multiple CPUs if your machine has them. If I had four CPUs, rpict could render four images in parallel. In the image above, you can see that two rpict processes are getting 99% of a CPUs resources. Trust me, this is cool.…

Continue Reading

Long Overdue Update


Hi. It's been a while. Rest assured, I am alive and well. But my lack of presence online and an untimely email outage actually led my friend John to think I actually was dead. I'm not. I'm alive. And busy. My last post was about my trip to the Oshkosh airshow. Since then, here's what's been goin' on: I passed the LEED accreditation exam, so now I am now a LEED accredited professional, or LEED A.P. If you want to talk about stormwater runoff management, or, say, innovative wastewater technologies, or perhaps the amount of operable windows you need for every 200 feet of perimeter space (space being defined by that zone within fifteen feet of the perimeter of…

Continue Reading

In the Company of Giants


I think that when you appear in the release notes for this software, you are officially a geek. Scroll down a ways, through all kinds of compu-lighting-geekery, and you will discover that yours truly has added a tiny piece of functionality to a fantastically complex piece of software, software that excels at modeling the ultimate complexity, light. While I realize that in comparison to all the work done by Greg Ward and several other giants in the Radiance community, my contribution—comprised of nothing more than a little copying and pasting from a shell script, I might add—amounts to the equivalent of a key grip credit on a Hollywood feature, I’m still pretty happy to…

Continue Reading

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…

Continue Reading

Geek Fest


Two weeks from today, I’m going to Berkeley, CA to attend the Second Annual Radiance Workshop”, where people from around the planet will convene for tutorials on using Radiance, and to share their experiences with the software. If you are into simulating light, then you are into Radiance (or you should be). So, gathering with some of the best Radiance minds in the world for a week will be educational, and tons of fun. I’m looking forward to it. Last year, the workshop was, for me, more of a kick in the ass to learn Radiance once and for all after struggling & dabbling with it in fits and starts for the last several years.…

Continue Reading

Trans flowchart


<p>Hi. Miss me? So, for the last week or so I have been struggling to understand some screwy results I&#8217;ve been getting with <a href="http://floyd.lbl.gov/radiance/">Radiance</a>, using the trans material to emulate some sun control shades. After a <a href="http://www.radiance-online.org/pipermail/radiance-general/2003-May/000732.html">flurry of emails</a> today from the very talented membership of the <a href="http://www.radiance-online.org/">radiance-online.org mailing list</a>, I think I have been shown the light. Specifically, I wanted to post a link to this <a href="http://www.schorsch.com/…

Continue Reading

pcond and small viewing angles


<p>OK, here&#8217;s another one. </p> <p>Problem: Running a site rendering (or any image with a very narrow viewing angle) through pcond -h causes the image to become blurry.</p> <p>Solution: Disable the visual acuity adjustment, thusly:</p> <p>pcond <del>h -a</del> image.pic > clearimage.pic</p>…

Continue Reading

Rendering falsecolor on glass with vwrays


vwrays -x XRES -y YRES -vf viewfile -fd | rtrace -h -fd -opn octree \ | rtrace -fdc -I renderoptions -x XRES -y YRES octree > illumpicture.pic The first rtrace computes the intersection point (which is fast) and the second rtrace does the illuminance calculation. Cool, yes? Yes.…

Continue Reading