THE VIRTUAL DDA

THE VIRTUAL DDA—A PILOT FOR

A 3-D ATLAS OF ANN ARBOR

Sandra L. Arlinghaus

February 2, 2004

Part of a continuing project:I hope to come away with a sense of what folks would like and then give it to them (pro bono), with timing reflecting various priorities.

All computer files are available online, http://www.InstituteOfMathematicalGeography.org/(follow link to current issue of Solstice) or from the author (by request to sarhaus@umich.edu )

All virtual reality models require that the free browser plug-in, Cosmo Player (go to Google and type in Cosmo Player to find a convenient download site) be loaded (in advance).

1.3D views of the DDA showing buildings without textures or detail—see online animation at link above showing a growing building at a site noted by The Mayor.The building grows from 3 to 12 stories and there are two views of it—one showing the impact of the new (red) building on the skyline and the other on the view looking west along Huron Street.Some of these files have been demonstrated to the Ordinance Revisions Committee of Planning Commission over the past year or more.List in this category is organized by ease of execution, beginning with easiest and moving to most difficult

Issues that are easy to deal with

Where are new buildings desired? Tell me some locations and I’ll build them.
How high—give me a range of heights and I’ll animate the scene, as in the demo.

Issues that are easy because the conceptual strategy is in place, but are a bit time-consuming:

Building footprints were digitized from aerials—the current digitizing is rough. How important is accuracy (tradeoff with time and with timing)?

Accuracy can be improved by simply spending time with more careful digitizing
Accuracy can be improved by field checking all positions, including using a GPS.

Building heights were extruded from files from Planning—again, the information is rough. How important is accuracy? Again, field checking and having folks look at the files can improve accuracy.

Issues that are somewhat more time-consuming and require some extra conceptual work

How important are upper story setbacks—these require extra digitizing and extra field work.
How important are building shadows—these require extra digitizing from the aerial, for existing buildings.

For proposed buildings, the might require use of GPS and calculation using trigonometry.
A quicker estimate is to use existing shadows as a rule for shadows for proposed buildings

Issues to think about that will take even more time and conceptual work:

How important are premiums?
How do you want to have setbacks enter the picture?
How do you want to use information if mapping extends beyond the DDA?

2. What style of output is desired?About a year ago, I took Karen Hart on a visit to the CAVE and the 3D lab at the Media Union.This past summer, Matt Naud came out to the CAVE, too.This past November, a group came to the GeoWall to view the skyline file and offered input.Input from Karen, from Matt, and from Jean Carlberg and Joan Lowenstein, as well as on a more casual basis from some members of the Ordinance Revisions Committee, has been helpful in shaping direction for this project.I’d also like to factor into the continuing work any priorities of this group.For example, Joan noted that she thought the files would be useful, pretty much as is, but that street names needed to be added (subsequently I added them—as one takes a closer look, they become evident).

Animations of VR have certain benefits and can be viewed easily online. Consider the animation in which a building “grows” across the street from City Hall.
VR files can be viewed online, on the GeoWall, or in the CAVE at the UM Media Union. If you want a GeoWall or CAVE display, it will take some time to schedule it. Generally, global files play well on the GeoWall and local files, only, play well in the CAVE.
Virtual experiences are exciting, but are just that—virtual. There are various ways of capturing them, from the easy animation of selected shots, to the amazing (but expensive) 3D printouts available at the Media Union (you can see sample items at the 3D lab).

3.Kelbaugh showed me maps from Planning involving buffers: I think it is an easy matter to make 3D maps from those files and

In the short run, make what you want and give you the output as an animation and as VR (requiring Cosmo Player) or other files and printouts.
In the mid-run, train someone to use the appropriate extension so that Planning becomes self reliant—do training at the University where we already have all the appropriate software. Planning already makes excellent use of GIS capability so it will not take much to give selected individuals a bit more training.
In the long-run, get the appropriate software for the City (through grants or some such) if it is not already available.

What I need next is to get files from Planning if you wish to pursue this direction.

4.Local view—see attached printout.This past fall, I agreed to serve as a “Faculty Advisor” in Prof. Peter Beier’s Engineering 477 course at UM.The name of the course is “Virtual Reality.”I worked with a group of four students throughout the term (with some input from colleagues Matt Naud and John Nystuen).The students took the base files I’d made linked at December 21a 2003 and field checked them for four blocks, one each direction from the intersection of Main and Liberty (see link to December 21b 2003 file).Then, they photographed that area, in detail, and applied the photographic evidence to the skeletal skyline to come up with a virtual reality file of that area.One view of that scene is attached.There is a certain roughness to this scene:

·the foreground has not been removed from the photographic evidence, so cars, people, trees, and so forth is plastered against the building—removal of the foreground should be done but is quite time-consuming.

·The street trees, sidewalks, streets, and other “artifacts” are simply virtual clip art.

·The building rooftop texture and street/sidewalk textures were not photographed

·Peter worked on the final file to reduce its size; these files take time to load.

5.Currently, I am working, with a team of associates (including John Nystuen, Matt Naud, 3D Lab at the Media Union, Mitch Rycus, Jerry Lax, Merle Johnson, Jim Turner, and Kris Oswalt) to generate a large grant that will produce files

·Of the entire city at least at the level of the animation files above

·Of the entire DDA at the level of detail showing photographic textures.

The grant will employ a number of students and others.One focus is to create this 3D model.The application is to Urban Security.The City will receive a copy of all completed files, as a 3D ATLAS OF ANN ARBOR, to use as it wishes—in Environmental Coordination, in Planning, and elsewhere.One component of the proposal involves creating a training facility at UM to train first-responders (on a regional basis).More will be forthcoming on this matter; work already done with 3D modeling of Ann Arbor, and work soon to be done, will serve as a pilot for this larger project.

Solstice: An Electronic Journal of Geography and Mathematics, Institute of Mathematical Geography, Ann Arbor, Michigan.
Volume XV, Number 1.
http://www.InstituteOfMathematicalGeography.org/