The View from the Top:  Visualizing Dowtown Ann Arbor in Three Dimensions
Sandra Arlinghaus, Frederick Beal, Douglas Kelbaugh *
Under Construction until at least June 7, 2004

     In previous issues of Solstice, a variety of 3D models of parts of the city of Ann Arbor have been presented as visual tools used in preliminary form by policy makers (in the Ordinance Revisions Committee of City of Ann Arbor Planning Commission) and as draft tools to which policy makers might respond.  This article chronicles the actual use of 3D models by the City of Ann Arbor Taskforce to Increase Residential in the Downtown.  The Taskforce was charged with "...whatever is appropriate here...creating x number of new units of residential in the downtown."  The creation of the models was an interactive process between modeller (first author) and Taskforce, principally Kelbaugh (architect) and Beal (real estate development expert).  Other members of the Taskforce participated in various aspects of process and are listed at the end of this article.
    The focus in this paper is to display the models that were developed as a result of a six week interactive process between modeller and Taskforce.   The process began February 2, 2004.  On April 27, 2004, the models as they were at that stage were presented in a public hearing at City Hall.  Readers wishing to examine the developmental process of the models may find all materials attached to the following link; readers wishing to hear the public hearing may do so by listening to material attached to the following link (the audio file is quite large; over 126 mb).  We recommend, however, that readers wishing to follow either of these links do so after reading this more general article:  return to these links so that they are viewed in an appropriate developmental context.  Subsequent to an overview reading, the materials in this article serve as an historical archive:  primary source audio and video materials are captured in the context in which they were presented.  The internet offers a unique opportunity for such preservation in an environmentally sensitive manner. (Unlike film, the user may choose to focus exclusively on audio or video, or coordinate them.)

DDA:  2500 residential units / 25 years

April 27, 2004

Existing:
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
  • Includes all building footprints extruded according to heights currently available from the City of Ann Arbor Planning Department.
  • If heights are not available, a height of 3 stories was assigned arbitrarily, rather than leaving the height at 0 stories.
  • Building heights are converted to feet assuming a value of 12.5 feet per story (conversion to work appropriately with the software).  Eventually, more precise measurements of height in feet will be needed.
  • There are buildings within the floodway in the existing pattern.
  • Historic districts are noted in a shade of gray darker than the rest of the core

    • University of Michigan buildings are noted in a shade of gray lighter than the rest of the core.
  • Standards involving map accuracy and measurement issues are in progress.
The animation below emphasizes ONE new view:
YELLOW BUILDINGS ARE ON VACANT OR SURFACE PARKING LOTS;
BLUE BUILDINGS ARE ON HURON STREET (BUILT OVER EXISTING BUILDINGS, PERHAPS)
RED ARE INFILL ON LIBERTY, ASHLEY, FIRST, SOUTH MAIN (AND NORTH MAIN, OFF MAP)--BUILT OVER EXISTING BUILDINGS, PERHAPS
Tall: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
  • excludes from consideration all parcels
    • in a current historic district
    • in the floodway of Allen's Creek
    • whose centroid lies in the floodplain of Allen's Creek
    • currently containing a place of worship
    • designated as public lands of the University of Michigan, and most others, as well
    • containing existing parking structures
  • general model considerations:
    • each story is assigned a height of 12.5 feet
    • City of Ann Arbor contour files, with contour interval of 5 feet (spacing between successive contours is 5 feet), were used to generate a Triangulated Irregular Network to represent the topographic surface.  The buildings, roads, and so forth were then draped over this topographic surface.
    • Sun position:  was set in the south at a height of 42.28 degrees, simulating the position of the sun in the sky at noon in equinox conditions at the latitude of Ann Arbor.  This setting creates lighting of the buildings; it does not create shadows of the buildings on the ground (that is a separate process for the future).
  • within these constraints, 5,000,000 new square feet are added as follows:
    • yellow point towers erected on lands categorized as "vacant or surface parking."   Each tower has a 90 foot by 90 foot floor plate.Where suitable, they are erected on a three story platform.   The tower heights are 9, 12, and 15 stories; distances between adjacent towers on the same parcel are 50, 75, and 100 feet depending on height (9, 12, and 15 stories respectively).  Where possible (according to spacing requirements), taller towers are erected at lower elevations.
    • blue buildings are erected along Huron Street at heights of 9, 12, and 15 stories.  The position is arbitrary.
      • East of Division Street (to the right on the models) the front setbacks are 20 feet; west of Division Street front setbacks are 0 feet.  These selections are in keeping with the present front setback pattern of buildings already present on Huron.  The goal is to keep a uniform, rather than a staggered, appearance in front setbacks (consistent with a "Grand Boulevard" approach).
      • Rear setbacks are 40 feet; side setbacks are 10 feet.
      • Upper story setbacks beyond the third floor are 20 feet in structures west of Division.
    • red buildings
      • setbacks and lateral information:
        • have three story platforms
        • have upper story setbacks of 20 feet beyond the third story (except on a few small parcels that have only three story buildings)
        • have 40 foot rear setbacks, 10 foot side setbacks, and 0 foot front setbacks.
      • height and vertical information:
        • on Liberty Street may rise to a total height of 8 stories (including the three story platform) with the upper stories set back 20 feet from the three story platform
        • on 1st and Ashley Streets may rise to a total of 4 or 6 stories (50/50), with upper story setbacks of 20 feet above the third floor, arbitrarily placed
        • on North Main, out of the picture, rise to a height of 6 stories and have 20 foot setbacks from the road.  Building footprint is placed on the parcel in accordance with the golden ratio.
    In this style of plan, zoning follows spatial pattern of buildout.

GRAYSCALE IMAGE, BELOW, EMPHASIZES THE MASSING OF STRUCTURES
 

Virtual reality files with navigational paths, lower left corner of Cosmo Player, were created to show fly-throughs with navigational paths consistent from one model to the next (download and install Cosmo Player in your browser):  There are a number navigational viewpoints predefined in Cosmo Player for ease in navigation (or fly through at your own risk!).  In addition, predefined viewpoints enable comparison of identical views under different buildout scenarios.  The set of animations below corresponds to each of the two scenes, existing, and tall, viewed in that order from each of the four viewpoints.  Transitional frames were inserted so that the viewer might be able to see the new replacing the old.

Links to VR

Animations made from some VR viewpoints.

Link to Audio File of Public Hearing of April 27, 2004.

DDA:  Taskforce to increase residential in the downtown
May 10, 2004
Audio file of Public Hearing of April 27, 2004, delivered on CD, as a .wav file, to DDA.
The 3D modeling of the entire DDA is done using ESRI software so that the model works directly from existing city base map GIS files and associated database files.  The GIS is driven by the underlying database.  Hence, all information needed to do the mapping is available in the database (.dbf) files (which can be opened in Excel).  Here is some more information from the various databases associated with the variety of files (over 2000) generated in association with the various 3D models created in response to Ordinance Revision Committee (Planning Department and Commission), Taskforce, and other request (that has been ongoing over the past 2 or so years)

There are 739 buildings on 755 parcels in the DDA (some parcels have more than one building); some parcels have less than one building (a building overlaps more than one parcel), as with One North Main, Campus Inn, and Sloan Plaza.  Some of the new buildings, on vacant land or surface parking lots, also overlap more than one parcel, as in the Brown block or the Library block...and elsewhere in the yellow layer.  There are 418 parcels in the set of target parcels (see below* for definition) and 405 buildings on target parcels (again, some overlapping parcels but more frequently, there are multiple buildings on a single parcel).

Vacant or Surface Parking parcels

Parcel inventory:
Square footage background of base layer: * a target parcel is a DDA parcel that is not: public land, in an historic district, in the Allen Creek floodway, such that its centroid lies in the Allen Creek floodplain, a church parcel.

Thus,


Building inventory, smaller than parcel inventory
The following table answers the following questions:
     How many square feet are there currently in the built buildings?  How many if all premiums were used?  How many if all buildings less than 6 stories were to grow to 6?
     In the target population, using building footprints, same questions as above--then, how many new square feet are brought in, in the target parcels, by such vertical add-ons?

Current All Premiums Used Six by right
All Buildings 7.5 million 13.4 million 15.6 million
Targets, only 4.9 million 8 million 9.3 million
New for targets 3.1 million 4.4 million

 

May 10:
Response to public hearing in relation to 3D model buildout:

Total in this model, with expanded yellow layer reduced in height and the addition of S. University along with a reduction in the blue layer and in the N. Main layer:  5,351,209.778
Click here for virtual reality; download Cortona or Cosmo Player, first, then view in your browser.  There is the same set of viewpoints as previously available plus two new ones along South University.

Colored virtual reality model
Grayscale virtual reality model
 
 

An additional color (green) might be used to separate, visually, the Ashley/First buildings from others.  Added colors may offer certain focused clarification of the model; however, they also fragment the visualization power of the model, as a whole.  There are merits and drawbacks; the needs of individual cases will determine how many colors to use.
 

Animations of selected viewpoints from the Virtual Reality files; please feel free to suggest other viewpoints to put into the VR files.

Sequence of animation frames:  gray is existing followed by taller scene of April 27 followed by shorter scene of May 10.

View from South Main

View from Main and William

View from Main and Washington

View from Main and Huron, looking North

View from Main and Huron, looking West

View from Main and Huron, looking East

View along Huron looking East from the west side

View along Huron looking West from State

View along S. University looking East from the Diag

View along S. University looking West from Washtenaw

Links to similar approaches:

http://depts.washington.edu/~uweek/archives/1998.08.AUG_06/_article2.html


Arlinghaus, Adjunct Professor, The University of Michigan; Director Spatial Analysis, Community Systems Foundation
Beal, President, Beal Construction
Kelbaugh, Dean, Taubman College of Architecture and Urban Planning, The University of Michigan.

Modeling work donated by S. Arlinghaus.