red echo

I gave my camera to my younger siblings Abigail (9) and Timothy (7) on Friday afternoon, and they took pictures until the batteries ran out. Here's what the world looks like through their eyes.

I built a new frontend for the Cuttlefish engine today, and now it can generate videos. It doesn't run in realtime yet, but the app lets you set up a video and then render it for later playback using QuickTime. Here are a few samples:

160x120, 5 sec, 0.9M	160x120, 60 sec, 5.2M	160x120, 30 sec, 4.4M	160x120, 15 sec, 3.7M
160x120, 30 sec, 3.4M	320x240, 60 sec, 10.1M	320x240, 20 sec, 3.5M	320x240, 20 sec, 3.5M

Video generation has been the obvious next step since I first started working on Starfish, but I've been waiting a long time for hardware to catch up. It's quite a thrill watching it finally get up and run. I may have jumped the gun by a year or two, in terms of realtime video, but this dual G5 machine comes really close and I might still be able to pull it off. In the meantime, I can think of a couple of people who are going to have lots of fun playing with the offline rendering mode.

I went out tonight intending to hit a couple of parties, but plans, as they often do, changed as I went along. I met up with Paul and Dana for dinner at Cactus, then after a little stroll along the waterfront and some tea we headed over to Adam's place. We met an Aussie and a couple of Canadians who were stopping over in Seattle on their way back to Whistler from Costa Rica, and spent a couple of hours relaxing in the basement with drinks and silly videos. After this began to wind down, I took off for the Alien Monkey Love Nest party over at CoCA. There were lots of familiar faces, the music was fully danceworthy, and the whole place was done up with black light reactive decorations. Much to my disappointment, my obnoxiously orange BRSD shirt - the only thing in my closet that even resembled the party's "day-glo" costume theme - failed to respond to blacklight at all. Oh, well! At least the laser backpack convinced the door staff that I was trying. It was two-thirty by the time I felt like leaving, so I never made it to the “Camp Blood” horror-movie costume party a few blocks away; but that was OK since I couldn't figure out what to wear anyway. All told a good evening indeed.

I spent the day setting up my new Mac G5. It's a little weird getting used to a mouse and full-sized keyboard again, after four years working on a laptop all day. I really like the big bright flat-panel monitor, though; display technology has come a long way.

The imminent arrival of this machine is what provoked me to start working on the Cuttlefish project, so of course that was the first program I copied over to run as a benchmark. The results were less impresive than I had hoped; this 2 GHz G5 only generates images about four times faster than my old 500 MHz G4 did. I haven't set Cuttlefish up for multithreading yet, so it's not taking advantage of the second processor, but I will have to dig around and figure out where the bottleneck is. I still have hopes that I will be able to run Cuttlefish in real time on this machine, by offloading some of the rendering work to the video card, but at least it's fast enough to render video clips now.

The 4x speedup seems to apply across the board, actually; that is the approximate level of improvement I see when compiling REALbasic 2005 and other large projects. The really cool thing, though, is that the second processor means I can keep working on other things while something compiles without slowing the compiler down. On the PowerBook, I pretty much had to just leave the machine be while it was busy crunching on code.

I'm happy to see that Apple has addressed some of the things that got under my skin with Mac OS X. They still haven't put the Open Files dialogs back the way they used to be, but I'm surprised to note that the list of volumes they added in 10.4 actually makes the dialog pretty comfortable again. With my new 19" monitor, the dock is so much less intrusive that I've actually turned off the “keep hidden until mouse-over” feature. The new platinum Finder look is widgety and strange, but it goes away when you turn the toolbar off, so I'm still happy. Mail.app looks and acts less like a toy; it has grown up into a pretty fair replacement for Outlook Express. It has a nice simple three-pane layout now instead of that awkward drawer, the “smart folders” are great, and they've fixed a number of my gripes relating to saved mail folders.

I started shopping for skybeam parts today, and ended up with two bikes and two training stands. These are the older style of training stands, where you remove the front wheel and bolt the fork onto the stand. The newer type are much smaller, and you simply bolt in the rear wheel, but I like the big frames better. They are heavier, which should make it easier to keep them from moving around - but mostly, I don't much like the idea of leaving fully functional bikes sitting out on the playa unattended. Missing their front wheels, I think my generator-bikes will be rather less tempting targets for theft.

I'm gearing up to begin work on this year's edition of the Human Skybeam, and I have a variety of design changes in mind. For starters, I'm going to scrap all of last year's custom bicycle fabrication: instead of converting bikes into stationary power-generators by welding on various brackets and swivels, I'm going to mount ordinary bikes onto modified training stands. These stands are already set up to hold a bicycle upright and to provide some kind of rolling resistance to the rear wheel, so all I need to invent is a way to connect the generators in place of the fan or magnetic resistance gadget. I don't know exactly how that will work, but I'm sure I'll be able to figure something out when I see the parts. I did briefly consider using training stands last year, but rejected the idea for budgetary reasons, not realizing you could get them so inexpensively second-hand.

The next major change will be the inclusion of a voltage regulator. I considered including such a device last year, but dropped it when it became clear that I was going to run out of time. It would have been nice to have it, though: lacking a limiter, people managed to pedal fast enough to burn out two of the lights on the first night I had them set up. I'd like my project to last a little longer this time!

Finally, I'm redesigning the lights, starting by replacing the flimsy spotlight gels with sheets of tinted plexiglas. The gels did not stand up at all well to the sun and wind, and caused me all kinds of trouble as I had to redesign the reflector system on the spot to keep from melting them. The reflector system itself turned out to be redundant; the auto headlight elements I used were focused well enough already. I'm going to leave the head of the tower alone, since the big silver dishes look really cool, but now they will simply be protective housings for the lamp elements instead of functional beam-focusing devices.

The result should be sturdier, more reliable, and easier to set up and take down. It will also involve a lot less construction than last year's edition, especially considering the fact that I can simply reuse the tower. In fact, I hope to have it ready for an initial test by early June; my goal is to have the whole thing done and ready to roll in time for Critical Massive.

I stopped in at Dorkbot last night, which as usual got my brain ticking with new ideas. Eric McNeill, creator of the big grid of LEDs at the most recent “People Doing Strange Things With Electricity” show, had some interesting comments about the circuitry he uses and the combinations of technical and human factors that influence his design decisions. One particularly interesting tidbit was his description of the microcontroller boards from Rabbit Semiconductor: you can get a 22-MHz computer the size of a keychain with four serial ports, 256K of memory, and an Ethernet port (!) for fifty bucks. Ahh, the possibilities...

My latest Burning Man-inspired project idea: combine the light-up blinky backpack with a water backpack. Burners always need to have water handy, and at night they need to be lit up so people don't run them over, so why not combine the two for the ultimate playa backpack? I imagine a lexan bottle rigged up with backpack straps and a hose with bite valve. I'd mount microphones on either side of the bottle, glue a battery pack underneath, slather the entire circuit board and all exposed wiring in epoxy to keep the water out, and mount the whole thing inside the water bottle. As you walked around, the LEDs inside your water bottle would pulse in time with the sound around you.

I've been investigating an idea for Cuttlefish that might make my performance goals much easier to achieve. The core algorithm is a big function that computes a value for a pixel, and this function has the handy property that every pixel's value depends solely on the (x,y) coordinates and the input parameters, and is thus independent of the values of any of its neighboring pixels. This, it turns out, means that it is really well suited for the sort of work modern video cards are apparently optimized for. I've been looking into the OpenGL Shading Language; it looks like it may be possible to port the most important parts of the Cuttlefish algorithm and run them directly on the GPU. I'm not entirely sure how practical this is, but it will be fun if it works.