Core Library
The terrain-rendering engine is built as libDemeter.so on UN!X’es and as Demeter.dll on Windows. This library is the only component of Demeter that is strictly required to render terrains in your application and it has no dependencies other than OpenGL. The centerpiece of this library is the Terrain class. By creating an instance of this class and calling methods on it such as Render(), GetElevation(), and Pick(), you can quickly build an application that displays a terrain and allows the user to interact with it.
The core library deals only with raw elevation and texture data in the form of arrays of floats and bytes. This means that if you want to use Demeter without using the optional Elevation Loader and Texture Loader modules, then your application will need to load its own elevation and image data by whatever means you like, and finally pass that data to the Terrain class as arrays of floats (for elevations) and arrays of bytes (for textures).
If you do not wish to load your own raw arrays of data, but would instead prefer to simply pass the names of image files, such as PNG, JPEG, BMP, etc. and digital elevation files such as DEM, SDTS, ArcGRID, etc. to the terrain engine, then you can use the Elevation Loader and Texture Loader modules rather than writing directly to the core library. The only penalty you must pay for using these optional Loader modules is that your application will be dependent on other libraries than OpenGL (each loader brings its own set of dependencies into your application).