APPENDIX

Summary of 3D Modeling

The Taskforce had the opportunity to view over 100 different 3D models of the DDA and other nearby regions. Because the models are three dimensional, they really cannot be captured in a two dimensional document.The figure below is included here simply to offer a picture of the style of model used:a structural model devoid of building textures or other detail.It offers the reader of this document, familiar with the existing downtown, a chance to view a 3D model in 2D and make some sense of it.Three-dimensional models of proposed realities are best viewed as three-dimensional files.A link to a site including all 3D and animated materials available to the Taskforce was included (does not work following completion of Taskforce effort):http://www.arlinghaus.net/ddaheight/To fly through the various models, the reader will need to download Cortona, a free download and easy to install, in the browser prior to attempting to view virtual models.Click on the next link to download Cortona: Cortona download.

The idea is simply to have models that allow the viewer to create a virtual downtown with buildings of heights determined by underlying zoning premises and other constraints.An increase in residential is an increase in density; when the increase in density occurs in a heavily built up area, that increase means extra height.Thus, a variety of models were built in virtual reality for the Taskforce to consider.

Some of the basic constraints in creating new virtual buildings were:

Some of the many models that were built responded to commentary from the Taskforce:the decisions they made helped to guide the models that were built.

Models were built based on:

·Alteration of zoning conditions:

oComplete buildout using only FAR, from lot line to lot line as well as from existing building footprints.

oPartial buildouts using only FAR, from lot line to lot line as well as from existing building footprints

oComplete buildout using a new zoning map suggested by Taskforce members

oPartial buildouts using a new zoning map suggested by Taskforce members

oComplete buildout focusing on point towers and other scenes suggested by Taskforce members

oPartial buildouts focousing on point towers and other scenes suggested by Taskforce members

·Environmental conditions:mixing the above with images of the Allen Creek floodway or floodplain.Models built with a variety of sun positions, some with floodway/floodplain showing, some not.

·Variation of height:many models were considered with point towers at various heights, buildings on Huron Street at various heights, sometimes with height adjusted to account for sun position.

oNew buildings on North Main—various models with various heights and setbacks.

oUse of upper story setbacks in many models.

·Alteration of territory considered

oModels were viewed both with and without University of Michigan buildings.

oModels were viewed that dealt only with the downtown core; others dealt with the full DDA region; still others considered parcels beyond the DDA region.

Some other technical issues

·Building footprints were digitized from aerials provided by the City.

·Extrusion of buildings was in units of feet; to convert to stories, to be consistent, a height of 12.5 feet per story was used.

·Excel files of the new attribute tables were created and information about square footage shared on the website above; associated Excel files were also made available for download

·Commentary from the public hearing was audio recorded and saved as a .wav file on a CD given to the DDA, for purposes of model cross-checking with input from that source.

·University building heights are exaggerated because building heights begin at grade level.Thus, underground layers are counted above ground, so that the underground stacks in the old Graduate Library appear above ground and make that building appear taller than it actually is.

A set of vantage points was programmed into the browser so that the human viewer could have a consistent set of views from one VR model to the other.That action also allowed for the capture of simultaneous slices of different VR models to create single animated scenes showing superimposition of changes with gradual transitions, fade in/fade out, from one scene to the next.Thus, Taskforce members had the opportunity to cut across the models from various directions: to fly around within a single model or to view a stack of images from a variety of models.Comparisons were therefore possible in all directions.

Three-dimensional models are a useful platform for considering the big picture that changes in increased opportunity might have on the downtown skyline, the perception of height, and the view of the city from different vantage points.Beyond that, they also served as catalysts to spark discussion on a variety of issues: with increased capability to visualize systematically what previously could only be imagined, the minds of leaders were left free to focus on various topics, ranging from the cultural, to the historical, to the management of infrastructure, as well asa host of others.The reader of this document wishing to have a fuller appreciation of the 3D material, its limits and opportunities, must take the plunge for him/her self into the wild world of virtual reality given on the link above.


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