The second objective was to create a terrain model of shade and shadows that may be useful for planning film shoots. Example results for the first objective can be viewed below. These seperate scenes were then composited and encoded into an MPEG file and can be played as an animated movie. In the examples below, we used a true-color composite Landsat TM digital satellite image as a drape. However, any GIS data file that is in the same map projection as the DEM can be draped over terrain including maps of geology, soils, roads, streams, etc.
Several factors affect the quality of the rendered terrain flyover.
In the examples below, a 30 meter pixel resolution satellite image is draped over a 30 meter pixel resolution digital elevation model. The resulting views cover a large area and allow for photo realistic terrain as viewed from high altitudes, however, the terrain quickly becomes blocky at low altitudes. Higher resolution sources can be used but result in longer rendering times and much larger animation files. A trade off has to be made between viewing resolution, rendered image size, flight path length, and flying altitude. Other parameters affecting rendered image resolution are rendered image size and interframe distance.