Originally, the Scene Graph relied upon its Terrain Loader for its terrain data. Therefore, the Scene Graph has a Terrain Loader class which can support quite a bit of manipulation and generation of data from Terrain Files.

The best support comes from the heightmap reader, which supports subdividing the terrain into small cells (for culling and LOD purposes), computing vertex normals, delauney triangulations, triangle stripping, and adding fake sun lighting/shadowing. (The heightmaps are generated from an external DEM to heighmap utility that I wrote, and is the preferred mechanism over direct DEM loading, which is slower and the DEM files are enormous.) The heightmap loader can also produce the ROAM terrain node, which will perform real-time terrain tessellation for each frame.

See the Scene Graph Terrain Page for full details on the original terrain loader.

Much of the technology that was developed for terrain loading was later advanced and adapted to perform as a terrain loader for the Carbon Graphics GEO modeler. This gives us the opportunity to develop our terrains in a real modeler then output them. Therefore, most terrain loading is now done via the GEO loader.

The ability to load real-time model formats and render them animating can be extremely useful. The standard uses are animating pieces of models to produce realistic scenes. This can take the form of animating props, rotors, or wheels on vehicles. Or even more important, properly animating the rotation of a tank turret.

Another common usage for animating real-time models is the simulation of cockpit avionics and heads up displays. Cockpit avionics can be modeled in a real-time modeler such as GEO then they can be run in a simulator, connected to simulation data. The GeoReal illustrates using the Scene Graph to perform this exact task, including connecting to simulation data without programming. Click here to read about the GeoReal application.