Archive for the 'Scale Issues' Category

Jul 06 2009

OpenSim Terrain notes, and Darb has Process Credit history!

I’d read about this, but never before experienced the agony first-hand.  Extracting funds from SL, the wait for funds to arrive at PayPal was a bit slow.  In fact, in the time it took funds to go from Linden to PayPal, a bamboo shoot in my back yard could have grown taller than me (that’s my RL not SL height!), and would have been over 2 meters tall.  Anyway, Process Credits are quite lacking in symmetry with how quickly credit charges can flow into the Linden realm.

During this week of waiting my random prims have been cleared out from Amida and nary a trace of Berkurodam BART Station remains besides a video in Gualala.  The video screen was actually entombed by a neighbor, who may not like it but did not send any message.

Anyway–for me this week is all about generating maps and graphics while keeping up with work.  I’ve generated a 50cm terrain grid for parts of my county where perhaps 150,000 people live.  With computational process improvements I should be able to make production stable enough to generate a 25cm grid.  The point is to model terrain slope and aspect within urban parcels.  OpenSim can pack 64 terrain megaprim sculpties over each region to refine terrain more than the built-in 1-meter postings, and display 10cm orthoimagery at full resolution.

Last year, I used first-return LiDAR data of the UC Berkeley campus to generate a 25cm grid for 10cm imagery.  Now, I’m working with bare-earth LiDAR data from FEMA, topographic contours (densified to 1.5m vertex spacing), and most importantly, photogrammetric terrain and water break lines.

Throwing all those data into the mix, the data are built into an ESRI Terrain Dataset, from which I generate TIN and GRID models at various reolution and extent.  The ESRI ArcGIS 3D Analyst Terrain-to-TIN generator breaks down after about 10 mega-faces (so would I…)  And the ArcGIS Terrain-to-GRID generator seems to drift into Windows-unconsciousness after about 1.0 giga-cells.  So for the grid, I break it down and do the pieces, then merge the tiles using ERDAS Imagine, because the ESRI ArcGIS raster mosaic function does not produce output grids much over 10 GB.  As annoying as learning these ArcGIS limits can be, it is very satisfying (and instructive) to see huge swaths of seamless terrain with great detail once it all comes together.  Thanks to the break lines, many driveways and most home building site cuts and fills are resolved.  And it will be a lot of terrain by OpenSim standards–enough to calibrate terrain for over 20,000 contiguous regions–not that I ever expect to build it all at 1:1 scale!

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Feb 24 2009

Civic Center terrain version 0.9 – dumped in Stanford region

The terrain forge was fired up tonight, and the virtual dump truck made dozens of runs into immersive reality.  Compared with OpenSim where terrain megaprims can be fine-tuned to the precise size requirement, in Second Life I must back-calculate the scale from actual terrain sculpties.  Apparently my trusty Gene Replacement 40-meter spheres can be induced into 35.70-meter terrain blocks, using the method I developed for use in Level 2 OpenSim build of UC Berkeley.  This version 0.9 of the terrain made some mis-calculations about the ultimate size of the top sections of each sculpted prim.  Look for better scale control with version 0.91 soon!

view Sly in RL, vu Ely in SL, northerly Stanford region

view Sly in RL, vu Ely in SL, northerly Stanford region

closer look at drive-under location ("first arch")

closer look at drive-under location ("first arch")

view Wly in RL, view Sly in SL Stanford region

view Wly in RL, view Sly in SL Stanford region

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Feb 16 2009

Terrain on tap – OpenSim on deck

There’s some progress on a couple of project fronts.  I’ve started assembling some USGS terrain for a 1:10 scale Level 1 build that could involve more OpenSim regions than I’ve ever stood up on one machine before.  Snapshot of progress is here, with a goal of 304 OpenSim regions for the model.  I expect that the OpenSim server will be re-imaged and a new build attempted in the next couple of weeks.

Vicinity of Colorado Springs, CO - with a full mile of terrain elevation subtracted

Vicinity of Colorado Springs, CO - with a full mile of terrain elevation subtracted

The site design for the Marin Civic Center build in Second Life Stanford region is also moving along with its target 1/8 region (two SL acres) based on RL terrain and building at 1:1 scale Level 3 build.  Progress sketch below:

Context model data of terrain for Civic Center Administration Building

Context model data of terrain for Civic Center Administration Building

A bit more can be reviewed by looking at the PDF of the same map here.cc_topo_20090211

Finally, a sky tag has been added to the space above the build. It is visible as a streak to anyone who visits SLURL.com by a mouse roll.  The Stanford region now has a large “MARIN” visible in its upper reach, squarely in the middle of the ancient Second Life Outlands.

Stanford vicinity from SLURL.com on 15 Feb 2009

Stanford vicinity from SLURL.com on 15 Feb 2009

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Feb 03 2009

SIMGIS Move: OpenSim for workbench, SL for presentation

Published by Darb under Marin Civic Center, Scale Issues

Down in the “basement” a server awaits a bit of configuration to become an OpenSim lab to support the Marin Civic Center development.  How nice it would be to load terrain into a portion of a Second Life region, but alas–it seems unavailable to those of us without Estate controls.  The 1:1.00 scale terrain will need to be calculated to back the base ortho-image that has already been tiled over the site as shown in the last blog posting.  I have verified that one of the 40-meter sphere oversize prims in my inventory can be rebuilt into a massive terrain sculptie.  Placing a 32×32 sampling (30×30 at most that are usable for terrain) of 1-meter terrain samples will give me a guide, and then I’ll just need to diddle with the SL client bulldozer tool to approximate the terrain prim, before disposing of it.

Thanks to the frequent updates of the region map at SLURL.com, I can already see some of the build taking shape.  On the second image below I sketched my virtual moving van’s path from Gualala to Stanford.  To aid overview map navigation and VFR-flying avatars, I have constructed a large readable sky label in crude imitation of the long-standing skywriting by SL resident Web Page in region Da_Boom.

Da Boom -- probably named after De Boom

Da Boom — probably named after De Boom

From that origin, the old Gualala locale was at region grid (1008,998), and the new Stanford site is at region grid (1006,1000).

The heart of the old SL Mainland

The heart of the old SL Mainland

Oddly enough, Stanford appears to be the fourth-oldest region, according to this relatively ancient map.

Second Life regions 2002 11 21

Second Life regions 2002 11 21

On the ground, I’m still in process on some lot line adjustment I’d like to make before breaking ground. The terrain sculptie method has been proven, although I have yet to grid actual terrain values for the project site. Also, I’m trying to minimize RL dimension measurements if possible, by using best available historical information on the RL site.

Some things have changed in SL viewers in the last few months. About a year ago, it was possible to take an oversize prim and modify a single dimension, having that snap to 10 meters. Currently, any change in a dimension of an oversize prim results in all three dimensions snapping to values less than or equal to 10 meters. It’s a new challenge, but can be managed. Still, once a builder has tasted the freedom of OpenSim, it is awfully hard not to chafe at those sorts of restrictions.

I’m giving thought to a copy of Second Inventory to facilitate the use of OpenSim for dev and SL for production, but the issue of prim size shrinking will be a big issue for me.

Curiously, I have found that physical prims to not drop to the ground in Stanford.  This has never been the case in Gualala, so I’m intrigued and opened a ticket with Linden Lab.  I’ll see what they say. Meanwhile, I’ll keep my eye on the sky for the project’s mark (in the old ceneter of OUTLANDS)

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Jan 31 2009

Marin Civic Center 1:1 scale texture in Stanford – feels bigger than OpenSim

Only the four-story Administration building (wing), not the two-story Hall of Justice. I’m tired so I’ll let the shot speak for me.

photo from 2009 01 30

photo from 2009 01 30

To me, it’s mildly amazing to realize that F.Ll.Wright’s design fits so snugly in 1/8 of a Second Life region at 1:1.00 scale.  The Civic Center Administration building is a Real-Life building that can be visited, providing an easy way to get a true RL immersive sense of its scale.  Building at 1:1 scale in Second Life for the first time, this has been my first experience of transferring that awareness into the multi-region contigous space of the very beautiful Second Life.  Sure, I’ve built large areas at 1:1 using draped LiDAR data, but to have a rather large single building (or at least its footprint for now) in context with existing builds that I’ve seen for months, well, at the moment SL seems larger than I’d thought.  That shift in my perception of SL scale may be the contrast between flying (quite fast as it turns out) around 40 to 100 OpenSim regions versus walking around the site and knowing how long it takes to traverse the RL building.

Anyway, check out the build’s progress at secondlife://Stanford/100/235/30

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Jan 13 2009

Meta-machinima, Berkurodam for sale, OpenSim server offline

After two years, it seems time to work on a new big build.  In the interest of conserving SL resources, I’m looking to get enough from selling the Gualala land and Berkurodam build to purchase adjacent land for a new build at the Stanford site.

I’m interested in selling the Berkeley build to architecturally-minded SL folk, so that with a properly sized and shaped parcel, I can do another RL scale model build (not based on any location in the East Bay). Work circumstances have changed and I’ll be spending much less RL time in Berkeley, so Inquiries are welcome care of darb (at) simgis.com.

Unfortunately, the public-facing OpenSim server that was loaded with the 40 region 1:1 scale UC Berkeley model has now been taken offline and is in search of a data center slot.

Meanwhile, just to prove that I’m still around the metaverse, I’ve made my first meta-machinima. Using the YouTube MP4 streaming service, which is apparently available for any uploaded video, one can map a texture into a video stream as part of parcel media settings on Linden servers.  This machinima was shot at the Gualala Level 3 Berkurodam build.

For those with the site blocked, the URL is http://www.youtube.com/watch?v=Ntjkj4eyQvM 
I’m embedding the video below

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Dec 11 2008

A time for OpenSim reflection – standalone Linden servers on the horizon

Silent though these pages be, much has been thought.  I’ve had some quality time with inquisitive Lindens and learned to expect some sort of standalone Linden server product along about 2009.  For me, that’s a game-changer as it’s hard enough to suggest (at work) creating content without also keeping up with an open source thread to stand that content up upon.

This past week I’ve made a real-life geographic shift for a family event, and learned that I’ve got a relation involved in the study of architecture.  That insight has reinvigorated my interest in Jon Brouchoud and some of his writing here.  The notion of architecture as it is currently an academic subject, versus architecture as a current professional practice, and the disruptive possibility of widespread virtual world deployment—this is a notion not so different from geographic science as an academic subject, GIS as a professional practice, and the possibility of immersive 3D disruption of the status quo.

Others in academic circles, including University College London, Centre for Advanced Spatial Analysis (CASA), published a Working Paper about the time this past summer when I was so focused on my 1:1 immersive build.  It was gratifying to see the CASA acknowledge Second Life technology’s place in the world of neogeography and geospatial informatics.

Sitting side by side yet somehow abstracted from mapping, gaming and digital earths
is Second Life and other similar virtual environments. Second Life and their like are
easy to dismiss as pure distraction and entertainment. Yet look under the lid of
Second Life and it contains one of the most powerful geographical data visualisation
kits available

And the fine writing and attention to detail of Jon / Keystone was spotlighted in NY Times’ Style magazine this past weekend.  It was a pleasure to share that link with architecture students!

It’s a big world, and immersive 3D systems must balance the tradeoff between quality and performant physics, and an economically practical level of large land areas served up to relatively sparse users, if we are to identify applications that consume vast tracts of GIS data.  Spanning that scale will require that standalone Linden servers have the ability to shortcut some of HAVOK’s demands to pile in many more than four regions per physical server.  After all, if I can get 100 regions stood up on a 1 GHz Celeron using OpenSim, then a four-threaded dual 64-bit Xeon server really ought to do the same for standalone Linden regions, right?  I surely hope so.

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Nov 19 2008

Immersive 3D article in BAAMA Journal – GIS in OpenSim and Second Life

Published by Darb under OpenSim, Scale Issues, osim.bargc.org

The San Francisco Bay Area Automated Mapping Association is our local URISA chapter, and publishes a twice-yearly journal that covers some interesting local geospatial projects.  The latest,  BAAMA Journal Volume 2, Issue 2 was released today for GIS Day.  It contains one article that provides an overview of the work blogged here: “IMMERSIVE 3D SIMULATOR-BASED GIS: SHARING THE 3D EXPERIENCEThe shot below details Mulford Hall on the UC Berkeley campus where our local GIS Day event was held again this year.  Thanks to the GIF, ASPRS, and BAAMA organizers!

Detail of 1:16 Level 2 model, in Second Life Agni grid, Amida region, on 2008 11 19 GIS Day

Detail of 1:16 Level 2 model, in Second Life Agni grid, Amida region, on 2008 11 19 GIS Day

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Oct 30 2008

GIS Day Video of Miniature OpenSim Builds in Second Life

One thing about these tiny builds is that they’re easy to see from one end to the other, so why not make a video of these miniature builds in Second Life?  I offer this for the amusement of Geospatial Information Service (or Geographic Information Systems if you prefer) folks who may be introducing themselves to immersive 3D.  International GIS Day will be here in a couple of weeks, so I’m posting this now.

 I’ve also challenged myself to improve my video production standards.  Who knows, maybe more than 1300 people will view it if I make it more fun to watch with a bit of editing and title-based metadata?  Nothing deep is intended with the score, it just caught my attention as matching the length of the machinima rushes tonight.

I’ve tried to improve the video with some titles to explain what’s being seen at the Level 1 (bare earth with draped ortho) 1:42-scale build, Level 2 (first-return reflective LiDAR gridded surface with draped ortho) 1:16-scale build, and Level 3 (full immersive 3D vector features in Second Life primitives with real world textures) 1:3-scale build.

If the embedded link does not work, the video is hereколи под наем which is at http://www.youtube.com/v/6joRvDH52jU

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Oct 28 2008

Glimpses of Berkurodam in Second Life for GIS Day

The 10th annual GIS day is arriving on 2008 11 19, and an article on the techniques that I’ve been blogging may be published on that day. In anticipation of that article, I’ve taken some time to upload selected strips of the Open Berkurodam model that has been built at 1:1.024 scale on 40 OpenSim simulator regions to Second Life. In that way, many more people may find this work and take a closer look.

In the article are three terms I’m suggesting be used for work that involves translation of GIS data into immersive 3D simulator environments: Level 1 build, Level 2 build, and Level 3 build. Level 1 is like Google Earth or MS Virtual Earth, basically bare earth gridded terrain with draped orthoimagery. Level 2 is what I’ve got as a placeholder in the Open Berkurodam 40-region 1:1-scale build, with a reflective LiDAR gridded surface draped with orthoimagery. Level 3 is just standard immersive 3D vector features that fill so much of Second Life, but in the special case of an immersive 3D build based on GIS-grade scaled mapping of building exteriors and possibly interiors.

The Level 3 build was what inspired my efforts starting back in October 2006 (Darb Dabney just has his second Rez-day celebration), but the Level 2 seems like the most important one for actual civic builds, because the grid of LiDAR data brings full-scale, full coverage data to hold the place and fill the mass of both buildings and trees, until one can afford to create the Level 3 build.

So now at the SIMGIS land in Stanford, there is both a Level 1 model (bare earth terrain with draped orthoimagery) of the entire 40-region sim at a reduced 1:42 scale, as well as a Level 2 model (gridded LiDAR first-return surface with draped orthoimagery) from the Berkeley BART station up Center Street, and on to the UC Berkeley Campus at Mulford Hall at a reduced 1:16 scale. It’s fun to see these tiny models, and it helps to convey some of the value that OpenSim offers those of us who would publish entire cities. A copy of these two models has also been placed in Amida, just across the channel from Gualala.

My selection of that path between BART and Mulford Hall was made to offer an entertaining Level 2 swath for those who would be taking transit to an ASPRS – BAAMA – GIF GIS Day event.

First the view in Second Life from Amida toward Gualala, with my Level 1 (1:42 scale), Level 2 (1:16 scale), and Level 3 (1:3 scale) (full immersive vector features with interiors) models of the downtown Berkkeley BART area. Second is the view of the SIMGIS Stanford site, with the same Level 1 (1/42-scale) and Level 2 (1/16-scale) builds.

Level 1 (1/42 scale) at base, Level 2 (1/16 scale) and Level 3 (1/3 scale) in distance

Level 1 (1/42 scale) at base, Level 2 (1/16 scale) and Level 3 (1/3 scale) in distanceAnd here's a view of the new SIMGIS Stanford region site, as viewed from Hawthorne region. The Level 1 model 1/42-scale is just above the water, and the Level 2 model 1/16-scale is above it.

Level 1 (1/42-scale) above water, and Level 2 (1/16-scale) above that.

Level 1 (1/42-scale) above water, and Level 2 (1/16-scale) above that.

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