We could say that this Terragen model is a side effect of our scientific research which purpose was glaciers reconstruction. We just wanted to be closer to realistic landscape as much as possible. So before using Terragen we spent much time to recreating glaciers geometry in GIS. For do this we collect in the filed data of moraines and glacier erosional landforms, which are indicator of former glacier extent. Using a base DEM of a present topography, we drawn in detail ice-surface contours in 25 m equidistant in shape polyline file. In GIS we generated glacier DEM from contours using topo to raster tool in ArcGIS. We merged the base DEM and glacier DEM to the one raster (TIF) which was then exported to Terragen. Utilising some GIS tools we were able to create several masks in rasters. One of these masks is glacier extent raster which allowed us to set different effects on glacier surface.
Animated glacier change, hmm... we also thought about this. Taking our method, which is based in real world DEMs, it would require creating hundreds of different glacier DEMs
. So no way. But if anyone knows a way to make animation of topography (glacier) change using several a little different real world terrains, let us know how. Let say we have two different glacier models, in maximum and recessional stage. Considering glacier retreat, can we use something like displacement which goes down from one terrain surface to second one below and rate of this displacement is depended on elevation distance between these terrains?