Archive for the 'BART Station' Category

Jun 15 2007

Berkurodam 1.1 has been attained

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.


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

No responses yet

Apr 08 2007

Berkurodam 1.0.1 is on grid

Published by under BART Station

Something to Shout About
Overview of Berkurodam Station
Motivated by the need to present something relatively coherent at the California Geographic Information Systems 2007 Conference in Oakland last week, nearly all of the underground construction was completed at the Berkurodam site. The crunch was really clarifying in terms of what level of detail is desirable versus what level was practical for this particular presentation. As it was, my presentation in the late afternoon of 4 April was impacted by some grid downtime that very morning, and I was not able to generate the last-minute machinima that some folks attending my talk were expecting. For those with an interest and willingness to download 18MB of PowerPoint, that talk’s slides are here.

The very last touch that I struggled to include was a set of four soffits that I used to approximate what looks like segments of a dome in the physical Berkeley BART Station, above the mezzanine level and under the cupola. Amusingly, in my hyper-exhausted state I struggled to find the proper proportions for the Second Life tetrahedron prim (a prism that tapers to a point) that would form it into one half of a diagonally split cube. These I fit into four corners that had been formed by the four arches under the cupola. Of course, one must to do this without causing interference for those who ride the escalators. Also of course, all one needs is a lousy triangle to provide the same visual result – perhaps only in the physical station would one really want to fill that space with something that strengthens the ties among the arches. While I’m a bit uncertain about usage here – what I mean to say is that I could have floated a fascia in space and easily produced the same result that I painstakingly formed from a “solid” prism.

The ground surface was a usefully transluscent aerial photo for much of my construction work, but for presentation’s sake, I have temporarily made everything opaque brick. As a practical consideration, I have leveled the site near 25.5 meters, and have not yet paid proper respect to surface topography.

All mapped storm drains and sanitary sewers were included with estimated heights, and several remarkable close fits took shape. Part of my excitement about the value of the SL technique of full 3-d surface presentation is that many complex map layers of underground commodites become very simple, almost intuitive to observe when seen in 3-d. They just make obvious sense in a way that is far easier to read (from a well-chosen perspective) than any superposition of 2-d maps with transparency or symbology.

As of version 1.0.1, Berkurodam is in a draft final state below ground surface. Currently, on the ground surface and above there are only placeholder boxes for about eight structures having photoreal textures—but textures that have not yet been through the rigorous rectification process using ERDAS Imagine, and was applied to several key textures within the BART station. In addition to improvements in texture squareness, I have yet to make proper use of the new 10cm aerial photo, nor yet to build streets, curbs, medians, parking meters, street lights, traffic signals, trees, news racks, and various signs. That surficial detail is targeted for completion prior to the ESRI User Conference in mid-June.

As one of several key learnings I was fortunate to take away from the CalGIS 2007 conference, I now see the importance of cloning the surface building work using Google SketchUp, essentially to re-use the textures and generate far greater visibility for this project than I would otherwise get from SL blogs alone.

There was much more to say about my learnings at the CalGIS conference, but for this evening, it must wait.  Here are a couple more shots from Second Life for perspective.
side view (southerly from canal at edge of parcel)

Main Berkurodam station mezzanine

No responses yet

Mar 27 2007

Textures – the sensuous, the gritty, and the real

Published by under BART Station

Darb's visit to Architecture Island

Much detail has taken shape inside Berkurodam BART satation these past two weeks, even as class projects grow in the parcel across the street. I worked with some of my (un-permitted) in-station shots to create photoreal textures, and realized that some of what was not working quite well had to do with transparency. Thanks to site-focused Google searches such as

site: transparency

I have become familiar with the sticky posts by Chosen Few and Robin Sojourner, and I’m getting much better use of my Photoshop skills thanks to their clear and to-purpose Howtos. My self-generated texture quality grows slowly through experience. I’ve bumped up against the awkward challenge of transparent texture rendering order (on my X1300Pro graphics card) but I’m sticking with what I’ve done for now. There are just so many features in the BART station that require transparency for completeness.

Thanks to the friendly communications from the group “RL Architects in SL”, I feel a part of a much larger community-within-a-community now. It’s like good Berkeley kharma is rubbing off onto the soles of my avatar’s stubby little feet.

There will soon be some new aerial photos as part of a survey conducted by Alameda county that should enhance the RL site mapping beneath which Berkurodam station is being constructed. I’ve also gained a few anecdotal insights about some of the underground commodities that I will be placing under the streets. My time is getting very tight for the conference presentation, and I must get done with some of the textures that I have sunk loads of time into, and in several cases this constraint is helping me to converge to a level of build quality that is, from among the universe of possible choices, the best that I can do in the time that I have.

Finally, though, I feel that I must comment on my experience of seeing ever more detail in the RL BART station. Every day that I pass through it at lunch, it seems I notice new details that I had never noticed in decades of previous visits. I notice them now because the SL Berkurodam model has acquired enough accuracy to be able to use these details. For example, under the cupola is a ring of brick trim that is four or five feet high. The part of this ring that one faces going down the escalator is nearly vertical, but there is progressively more taper back away from the opening on the parts of the ring near the tops of the escalators. (This surely must read wierdly) Fact is, this detail mattered enough that it made it possible to fit my avatar down the escalator where he got stuck before.

On the underside of this brick-faced ring there is a two-to-three foot space with lights underneath before another lower ring, one that is white and textured like all the arched beams in the mezzanine. As it turns out, I built that lower ring in the correct proportion to avoid the Av interference that I mentioned before. Days later, on one of my walks through the RL station, I realized that it was actually built that way although I hadn’t noted that in my sketches and I hadn’t photographed it for reference either. Despite whatever this tells me about my stunning lack of observational acuity when it comes to architectural interior space, I felt a deep realization that there is something inherenty practical in the level of accuracy that is taking shape in my SL build. It’s not about my build skills, but rather about the potential for detail in the current SL set of prims [attributed 3-d points constrained by Havok Physics engine, version 1].


No responses yet

Feb 02 2007

In Touch With Textures

Published by under BART Station,SL In General

Berkurodam on 20070202

With some preliminary surface features in place now, there are textures on the station cupola and easterly face of 2150 SHATTUCK AVE. I used my venerable Canon A-1 with Canon FD 14mm f2.8 L rectilinear wide angle lens to capture some textures. After getting things pretty well squared up with the powerful analog optics, I made a 35mm shot, had it processed at Long’s Drugs where one can now get 35mm film processed directly to CD for $2.99/roll with C-41 processing and an index print. If one asks for the “5×7” scan resolution, there is a 1535 x 2137 (3.1 Mpel) scan for every full frame which throws out a fair bit of detail but seems adequate for most 512 x 512 textures in SL.

I tried fairly hard to get the subject building face filling as much of my field-of-view as possible, knowing that the CD scan will be less than I’d try to squeeze off from a 4×6 (10cm x 15 cm) glossy print in my own scanner.

Despite my best efforts in the viewfinder, things always seem a bit warped in the scan when I first view them on the screen. For that, I bring out the big guns. Using Adobe Illustrator I make a sketch of any repeating geometry that is in the building (say 11 floors and 16 windows per floor), render that as a TIFF and use that for registration in ERDAS Imagine. With a second-order polynomial warp, perhaps 16 well-distributed control points, I can get the texture close enough to impress on first blush.

When grinding through the control points, one’s mind may wander. In my case, I considered the terminology of how ERDAS ground control points (GCP) as might help georeference an image are being used in this task as texture control points (TCP). There is no projection per se, but there certainly is a load of rectification going on. With ERDAS, it goes on about as well as one has the patience to give it.

No responses yet

Jan 24 2007

Taking Shape

Tonight the ramps that serve as placeholders for the main entrance and exit escalators are in place under a provisionally textured cupola. Pudgy Darb fits down the ramps with a ~20% boost in width relative to RL escalators.

I’ve started to get the notion of how Darb now maps into full scale RL. He’s somewhere around 183 cm (6 ft) tall and likely would scale up to a weight of 135 kilograms (298 lbs). Because of this, and the lack of flexibility in his arms, some of the 1/3.048 scaled dimensions may need minor expansions.

Also, it’s not clear to me precisely at what level does Darb hit his head and can’t walk under an object, because the blockage is occurring somewhere above his hair in what looks to be vacant space. When ducking through the mezzanine which is now under trusses and jumping down to the platform (because there aren’t yet stairs or escalators in place) it is a lot easier to use Mouselook. Pulling back to the typical view where I see the av’s back as the SL client normally does, the view point is about where Darb’s head would be if he weren’t a Tiny avatar. That is to say, POV is about 1.8 meters above his feet, although his Tiny makes him only about 60 cm tall.

In open space having a full-height POV on a Tiny av is not a problem. Inside a tightly scaled structure, however, it can be very disorienting–and sometimes just doesn’t work if the POV tracks an av walking underneath the floor the POV is floating over at nose-length.
All the same, it’s pretty cool to see Darb walk down the escalator turn around and walk back up the other escalator, walk around the gates and hop down to the platform. I’m just getting the first flashes of what a Mouselook machinima might look like.

Next up will be placing the four-foot-high divider properly to separate the paid and unpaid areas of the station, visit the RL station with a laser tape measure to get real ceiling heights and floating escalator lengths, and nail down structure dimensions.

After the structures are in place, I expect to rent a dual-head strobe unit at Adolph Gasser, buy a fistful of Ektapress for my venerable Canon A-1, and put my vintage FD-14L rectilinear lens to some serious texture acquisition. I’ve spoken about this lens’ great suitability for this purpose for many years—and finally I seem to be a couple of weeks away from actually putting textures usefully into place!

No responses yet

Jan 23 2007

A shade smaller is not better, but much easier

Published by under BART Station,SL In General

Full-scale Ruth for reference

When actually taking measurements with a foot-denominated wheel and transcribing to about 1/3 scale, it became clear earlier this week that what we really want to build at (to save L$ in purchased land and $ in tier fees) is to build at 1:3.048 scale, because that way our field notes taken in feet can be translated directly to decimeters. Practical value from experience.

Also, following directions found on, I was able to get the last 16 m2 plot of formerly abandoned land sold to me by a Linden. That leaves only a 32 m2 peninsula of an advertiser’s plot that I hope to work out a deal for. The goal is most worthy: to build the Jupiter beer garden in glorious 1/3.048 scale…

I joined the three SLGIS parcels together tonight as well, to simplify the settings for permissions after getting a complaint of exclusion. Also, I improved the music (on-parcel streaming audio) to motivate me as I build. The mezzanine’s scaled openings to the platform are now in place, although textures are placeholders. Also, my 60 cm-tall avatar can walk around on the platform and also under the trusses of the mezzanine without getting stuck. This has been a worry!

No responses yet

Jan 09 2007

Downtown Berkeley BART station progress

Published by under BART Station

earlier Darb on platform

I’ve sketched out some starter six-car trains, begun a platform, and put a few prims in place for the station’s mezzanine level, above the platform and about two floors below street level. I found that I could use the aerial orthoimage as a guide, but certain variables make it a guess to dimension objects below ground like a) depth below ground of the mezzanine, b) actual angle and length of the stairs and escalators, and c) actual dimensions and alignment of the island platform relative to the rotunda.

No responses yet

« Prev