Darb Dabney’s OpenSim Blog

What’s real-life terrain without real-life imagery to top it off with?

This is a view of Kentfield, Greenbrae, and the Corps of Engineers-enhanced portion of Corte Madera Creek.  The College of Marin athletic fields are on the left, Marin Catholic High School fields in the upper right, and Marin General Hospital in the lower right.  The NAIP imagery is textured on a flat 256 meter square prim fixed at 15 meters scaled elevation, so the sim’s terrain shows above it in several hilly places.

Here, another sim has Phoenix Reservoir and Bill Williams Canyon, both above Ross, California.  Mt. Tamalpais East Peak is behind the lake but does not yet have specific texture on it.  The edge of another 256-meter square prim with the next orthoimage tile to the west is visible in the right.  Two sims farther west, all of Bon Tempe reservoir imagery has been nestled within its proper terrain.

I wish that I could simply use my orthoimagery as a drape over the terrain; alas, that does not seem to be an OpenSim (or Second Life) priority at this time.  None the less, I have already created the first seven sims’ worth of image tiles, and they can be used to provide horizontal control for a great amount of future construction.

Whee! The OpenSim experience grows more wondrous each week. My humble trash-to-testing server, 1 GHz Celeron, 1.5 GB memory, Ubuntu Gutsy Gibbon, is now running at capacity: 49 standalone OpenSim regions, seamlessly covered in 1:4.57-scale real-life terrain, a single user and just the first couple of prims.

The scale works out to a real-life terrain square almost 8.2 kilometers on a side.

The very first couple of prims have gone in to mimic the Gardner Fire Lookout on top of East Peak.

This feels like a bona fide breakthrough for me, knowing that prototypes of Berkeley could be set up, perhaps 49 regions to a test box, on just 10 servers for starters. That would be supporting a 1:1 scale, 500-region model of the City. Much to think about!

My open-source mental nodules have really had a feast these past couple of weeks. First, I had a great insight when I finally listened to a colleague who had spoken well of Ubuntu for some time. When I started using Feisty Fawn and got far, well, and with an attractive and performant result and little effort, I knew that things had evolved well in the past few months.

My previous favorite was a CentOS 4.3 upon which I installed a large commercial mapping package (ESRI ArcIMS 9.1) over Apache and Tomcat. The vendor supported an RHEL configuration and I got close enough for very few problems with CentOS.

But at the home lab, my hardware had to be wrung from random bits of machine that left me with a 1 GHz Celeron / 1.5 GB memory on an ABIT VH6T board, and a new 160 GB PATA disk. First I installed server, but then just relaxed and had Ubuntu Feisty just slide into place. My goal with this box was to dedicate it to OpenSimulator.org testing. In the process of getting Mono, LibSL, and OpenDynamicsEngine all built in place, I also elected to update to Gutsy Gibbon.

Late last week I got first one, then four OpenSim regions working with default starter islands. Next, I applied some spatial resources (ERDAS Imagine) to extract an appropriate amount of real-life digital terrain data. As I am wont to do with my RL-related builds, I scaled down my canyon of interest (Strawberry Canyon above the UC Berkeley campus) to 1/4 scale so it would fit on my four sims.

Just a few tweaks were needed for my extract.
First, ERDAS Imagine has a ton of export formats, and I ended up having success with the IEEE 32-bit floating point format, using swapped bytes (not unswapped, nor any specified -endian flavor).

When I had success, it took me a fiew minutes to realize that the sim was reading in X and Y in a swapped order from the RAW file, and so my terrain had a 90-degree counter-clockwise rotation relative to the original. My original is in WGS84 UTM zone 10 north meters, and has a two-meter posting interval so that it would have come in as a 1/2-scale terrain in OpenSim. I downsampled my terrain clip to a 4-meter interval and rotated it 90 degrees clockwise, then exported a 1K by 1K raw float as described above. It worked just fine and dandy for my first four sims.

Next I worked on a (now I know) naive goal of taking the correponding area’s orothoimagery to drape over my shiny new terrain. I prepared a co-registered 1K by 1K, 24-bit Targa file, then sliced it up into four tiles for my four sims. When I loaded it in using the Estate controls, was I ever surprised! Not only was my pixel-perfect texture tiled all over the place, I realized that there isn’t any way in the Estate controls to change that repeat.

Thanks to nebadon for helping me realize that there’s just no hope for the draped orthoimagery, before I tried too hard to find a magic tweak that wasn’t going to be there. I’ll be able to set up buildings in their proper places using orthoimagery on a sim-sized megaprim, so I’m not totally stumped.

But all in all, my open source nodules are overflowing with wondrous Ubuntu, Mono, and OpenSim progress this past week. I’ve also set myself a goal of modeling Mt. Tamalpais in time to make a poster for the AGU.org Fall Meeting in early December in San Francisco. If I tune the terrain along the fire roads, it might someday be possible to actually ride a virtual mountain bike around the summit of a 1/4-scale East Peak, on an 8 x 8 standalone set of sims.

Nuff for now: here’s Strawberry Canyon towards sunset. Four OpenSim regions with one continuous RL terrain.

The main page at SecondLife.com has lost its counter of resident accounts, but a year’s worth of calibrated experience suggests that the count is rolling over 10 million about now.

Much more concretely, it is with IMMENSE pleasure that we are happy to welcome a new collaborator avatar Rat Dawg, new to Second Life this month, but very persistent with the following of directions from OpenMetaverse. A wonderful recycling of an ancient 1 GHz Celeron with 1.5 GB of memory, fresh installs of Ubuntu Feisty, Mono, and OpenSim have made a new world!

The current SecondLife client 1.18.3 (5) worked swimmingly; sculpties were fine as long as they didn’t emit light (whereupon they reverted to toruses!) and the modifications of terrain were laggy. Otherwise it was an awesome thing to see stuff happening like uploads without any visible debiting of L$, and the uploads were near-instantaneous over the local network.

OpenSim is at Alpha 0.4, but most assuredly worth a look. Having success with it in a Windows-free environment, learning more about Mono and getting major (open source) environmental benefits from it is so fine. Thanks to Ubuntu, I really start to feel like some of my brain cells are awakening from a twelve-year-long, NT-induced stupor. What’s more, I really have a much warmer, fuzzier feeling about collaborating with dotNET developers, knowing that their fine work need not run on servers beholden to Redmond WA.

-=Darb

Silence is not becoming of a little blogging avatar. I’ve posted here and there, nagging others and such over the past 10 weeks or so. I’ve even missed the 9 millionth SL account somewhere along the line. But despite my silence in this space, it’s not like I’ve been sitting on my spherical posterior!

In August I brought together a few bits of technology, tested out a Vista-based budget PC with a little ATI Radeon X1500 upgrade to its graphics. Lo! and behold, somehow the SL viewer worked OK under Vista. Annoyingly, the MS OS trolls rated the native ATI driver at a lower “Windows Experience” rating than the default MS graphics card driver. But the Pentium Duo box was fairly stomping for around $550 with the upgrade. Later in the month (OK, maybe a couple of days later) I wedged the box into luggage and got it set up about 10 zones easterly of SL time.

The cool part was being set up in a medium-sized eastern European city, with cable modem, trucking around SL and having perfectly nominal voice conversations with known avatars. I may have been many thousands of RL miles displaced from home, but I had to say so to have anyone notice. In fact, they were probably a bit skeptical about my claims (like many people might be the first time they get an overseas Skype call.) Try as I might, there wasn’t any difference in the experience that I could tell between using voice-enabled SL in the SF Bay area, and using it in Romania. SL might eventually turn out to be a pleasant supplement to webcam conversations.

Technology-wise I’ve also gained a bunch of media knowledge in these quiet weeks. Thanks to the good folks at Berkeley Community Media, I copped 24 hours of training in field production and Apple Final Cut Pro; for someone like me who has almost enough undergrad and graduate Documentary Film Studies classes to get a minor, it is wonderfully refreshing to see non-linear editing in action. Sure, I’ve got a copy of Adobe Premiere Elements in the home lab running on a PIII/800 Coppermine, and I keep a Pentium D running XP Media Center edition to get some DV capture action happening. But compared to a Dual-Xeon 3 GHz G5 Mac with 4 GB of memory and Final Cut Pro, it’s kids’ stuff that I have at home.

Add some FRAPS action and the SL script Filming Path (from Geuis Dassin and Nand Nerd), and I feel equipped to exploit the Berkurodam build as a sound stage. Now if only I had talent to match my technology…

I did set up a burning car crash in Berkurodam and then neglected to clean it up for several days. Apparently some of my neighbors were displeased, or a strolling Linden took exception to the air pollution that was released by the fire, and (embarrassingly) the mess was cleaned up by them and returned to me. After that, I’m determined that any carnage left on the Berkurodam set will be cleaned up shortly after filming.

Also, in another mainland area, I’ve built a machinima studio of moderately grand proportions, and had some dialog with not-so-near neighbors who suggested ways of lowering my albedo, particularly at night. With very little effort, I blissfully got with the Goth program and have had some fun. Now the studio is a one-acre tower with a shroud of darkness on the outside, and chroma key blue glowing on the inside.

Again this semester, I’m very glad to say that there is a student group has been willing to set up a term project in Second Life. There’s no more space in Gualala, but there should be plenty in the machinima studio for the time being. I look forward to their construction!

Finally, before I fade into RL dreamland, I want to echo my appreciation for Orange Montagne’s book Metaverse Manifesto that I read over the Summer. It’s great! While I haven’t heard from Mr. O directly, I was pleased to post a review of the book on Amazon where I got my copy and recognized today that he’s read the review.