Darb Dabney's 3d GIS – OpenSim

Nothing like a user conference to motivate poster production! Somehow the chance to share work with perhaps 20,000+ eyeballs at the San Diego Convention Center always adds a bit to the excitement. There are now eight 3-foot by 4-foot color posters that emphasize shots of the progress made on the land surface, buildings, street signs, street lighting, sidewalk lighting, and foliage.

Oh, and there’s one other panel that has SL snapshot images for decoration, but is really a little manifesto of the importance of metaverses (in 2007) to the future of spatial systems.

This is Darb’s manifesto posted for attendees in the Map Gallery of the ESRI International User Conference in the Sail Room of the San Diego Convention center, 18–22 June 2007
The attendees are geographic information systems professionals, managers, and supporting industry folk who largely work with maps, map servers, and related technology for a living.

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YOU WILL SOON WANT A METAVERSE FOR YOUR SPATIAL DATA

Metaverses are immersive 3D computer graphics platforms
- They are not too much like 2-1/2D raised terrain or globes.
- Their objects may not support the vertex model of GIS or CAD,
but use parametric points or U-V maps and raster textures instead
- Through a viewer or other tools, metaverses immerse the user into the 3D model.
- An immersed user is as likely to look up or under as a globe user is to look downward.

If the metaverse holds a model built honoring GIS data, then a metaverse might
- Place the user into the map
- Allow one to stroll through a geodatabase
- Publish spatial data in real-time 3D for very many simultaneous users

Metaverses can allow massively simultaneous at-will rendering in near-real time
- As an example, Second Life is built on grid computing with >5000 processor cores
- Second life spatial data are integrated parametric point objects and raster textures
(34 Terabytes as of 5 May 2007)
- Second life supports over 40,000 simultaneous users worldwide with streaming audio and video.
Integrated VOIP is in beta.

Open-source options exist for single regions, and are developing for grids
- Second Life’s producer, Linden Lab, has announced plans to open source their server code
- This would allow cost of hardware / server power / model development to become the
limiting factors for a civic-scale metaverse
- City of Berkeley could stand up a 1:1 scale immersive model on about 512 processor cores,
or 1k cores with a redundant grid

Metaverses typically include a physics engine
- this manages object collisions and optionally provides gravity and
- in Second Life, the physics engine in each processor core handles collisions among
up to 15,000 objects in the core’s region.
- the engine does so at 40 Hz (forty cycles per second) to allow rendering throughout
the region as real-time movies for each client.

Metaverses will change your data center expectations
- There will be a desire to build out grid computing
- Performance will be tied to processor cores, while most related resources such as
system memory and disk storage (per core) are not exceptional
- In metavserses, the simulated space expands linearly with the number of regions in your grid.
Second life has 64K square meters, about 16 acres, at 1:1 scale, for each processor core
- people interested in grid computing are very interested in having processors with more cores
- these people may be equally uninterested in having operating system costs, or even server application costs, scale with the number of cores

SL Darb Dabney, Berkeley, California 20070615

Yea sure, resident accounts do slide upward. I recall seeing concurrency over 42,000 on Sunday 3 June. What I’m struck by this blog cycle is how sticky the figure of about 1.7 million distinct logins in the past 60 days has become. Also, I find myself facing a tedious day now and then when checking “second life” as a search term on news.google.com and finding certain very persistent themes, and a day or two between what still seems new+exciting stuff. Surely I might be getting adjusted, but I’m left with a bit of a nagging impression, like the persistent 1.7 mil uniques in 60 days, that the active online SL community is more cruising along than growing explosively these past couple of months.

But in my little corner of Gualala, there has been some intense building and changes. To the detriment of RL household serenity, I’ve probably logged something more than 20 hours/week on Berkurodam construction in the past month. What’s made it more intense has been an initial, perhaps misplaced, goal of trying to get material together for the Fifth International Symposium on Digital Earth at the UC Berkeley campus. That hasn’t happened, but the desire to show off some urban literalism, and the Berkurodam build’s current theme of surface features and street furniture has driven a few refinements. The hard deadline will be to prepare posters for this month’s 27th Annual User Conference for Environmental Systems Research Institute (ESRI) in San Diego. That means that I’ve got to consolidate my feces in time for a flight on 17 June, only twelve days away now.

And happily, it is coming together almost proudly. A handful of, shall one say, creative insights has led to some new mural panels surrounding the build in nearly all horizontal directions, and a somewhat extraordinary unification of the parcels westerly and northwesterly of The Street. What’s really drawn in hours of my attention has been gaining dexterity with sculpties.

Thanks to the blessed prose from Amanda Levitsky, and the foundational Wiki Book Blender 3D Noob to Pro, I got my start over a couple of evenings. Then as so often happens with these builds, one success inspires a couple of other attempts, and if one of those works out, the chain reaction of skill memes continues unto my exhaustion or distraction by RL issues. I’ve learned that it is important to start with a cylindrical UV space to get Blender filling the output image square. (I haven’t yet found Blender functions to crop the resulting UV image, nor to stretch a generated UV grid along a single axis) Just as the sim in Gualala seems now to accept 1K by1K texture images, the sculpties seem to max out at a 64 by 64 grid of 24-bit pixels in UV space.

Although the Linden Lab descriptions of sculpted prim applications emphasized organic shapes, my need was strictly inorganic: fire plugs, traffic signals, street light fixtures, and deco sidewalk lights. For a public works / asset management application, it seems crucial to stay quite close to a 1:1 ratio between cataloged asset and prim. Thus, if I can represent an asset such as one particular traffic signal fixture (say a basic red-yellow-greed triad) with a single prim (rather than a linked collection of four, six, or more cylinder and box prims) then it remains a simpler proposition to automatically convert a single GIS-managed 3D point into a SL traffic signal. Vice versa, if the [x,y,z] position of that traffic signal and its [roll, pitch, azimuth] orientation are tightly refined in the metaverse, it seems most natural to extract those attributes from a single prim into a GIS asset point. All philosophy of balance between GIS and metaverse object counts aside, it usefully conserves sim resources to use one sculpted prim rather than six where possible.

The last variable in the past month’s excitement has been the exceedingly useful release of Google Street View for the RL site that Berkurodam is modeling. As carefully as I like to take my own texture shots, having Street View online as a reference for object geometry and relative positions is stellar. I surely remember the MS Virtual Earth street-level imagery from Fall 2006, but by comparison their interface was odious. Thanks to MS for breaking the ground in a large-scale street-level web service, and thanks even more to Google for publishing an interface to similar data with vision in its soul. As an exercise in 3D visioning, I have located a half-dozen “shoot the shooter” images where I grabbed views of the acquisition platform. In Berkeley, it was a green minivan with the cameras seemingly disguised to register (in peripheral vision) as a black streamlined rooftop storage bin. Of course, the 15-cm diameter survey grade GPS antenna mounted behind it gave away its purpose to knowing eyes. But very few people seemed to notice the van on Berkeley streets, which is either a tribute to the van’s low profile, or a measure of pedestrian preoccupation. Who knows?