Campus Buildings Layers- Endless Editing

The buildings polygons from CAD files were just a starting point for developing a campus map. Next up, buildings in 3-D. To do that we used MS Virtual Earth's bird's eye view to estimate height of buildings by number of stories.

Buildings at AB Tech are like clusters of boxes, each with a different height. While the roof of a building may be almost flat, the building is made up of sections of varying heights. Many of the buildings had to be divided into a set of smaller polygons so each section could be extruded to a relative height.

This required a combination of:

• splitting existing polygons
  
• digitizing sub-polygons within existing building polygons


• digitizing new buildings polygons where a building was incomplete.
  

The aerial images were not quite in registration with the buildings polygons. They were clearly at the same scale, and were probably the source for the CAD files. This was tedious............This was occassion for reviewing editing techniques.

After working on the buildings layer, I brought in data on impervious surfaces from the City of Asheville geodatabase. This provided a good start to a paved roads and paved parking lots layer. On top of the campus aerial photo, I overlaid the impervious surfaces layer with transparency set at 66% so I could see everything. This made selecting roads and parking lots fairly easy. Some of the lots and roads had been changed by new construction and needed editing or digitizing.

The map looks good with buildings, roads, and parking lots along with utility poles and sidewalks fromt the CAD layers. Some decent sidewalks polygons could come out of the impervious surfaces. Oops outa time.