Real world 3D terrain in After Effects

Your chances of doing that in vanilla AE are pretty much zero and even in a 3D program it's not going to be a cakewalk. Generating meshes from actual DEM data is an exercise in itself and then so is optimizing the scene for rendering. There's a million things to consider from cell sizes to measurement data in teh files to the simple fact that there are different flavors of DEM and other geo data. The best way to proceed quite generally is to generate the 3D data in the program the data is managed by exporting it to a supported format like 3DS or DXF. Everything else is a pain in the rear, even if you use specialized scripts and plug-ins which exist for some programs. For AE you can always try GEOLayers (https://aescripts.com/geolayers/), but of course it's just a fake and still requires additional plug-ins to generate 3D displacement layers

Mylenium