High Level Bridge

By Greg Dooper

February 13, 2003

Created with POV-Ray for Windows v3.5, Moray for Windows v3.3 and ArcGIS.

This image is looking from the east end of the bridge westward towards the west side of the river valley. What's interesting about this image is that it used actual elevation data to create the coulee. A Digital Elevation Model (DEM) was acquired of the area between the High Level Bridge and Whoop-up Drive. This GIS dataset is simply a fancy image that contains height information in each pixel. Using ArcGIS, the DEM was converted to a Windows bitmap file. The bitmap could then be used as a source file to create a height field in Moray. Unfortunately, the coulee contours do not show up as well as I would have hoped them to.

The river was created by passing a plane through the height field. In the original DEM, the outline of the river was actually slightly lower than the rest of the land, so passing a plane though the very bottom of the height field would only show through where the river is situated. Note that the light source is set in the northwest, not quite realistic in the northern hemisphere, but it gave the best shading conditions from this viewpoint.

The DEM used to create the coulees

View from above looking down