Digimation has announced a sophisticated terrain library,
3D USA, which consists of terrain models for the 48 contiguous states.
The models use the Mercator projection, and consist of 4km terrain data with 1km satellite imagery for texture, bump, and displacement maps.
The terrain data has been decimated in low-slope areas only, thus providing detail in rough terrain while reducing needless complexity and file size. Polygon counts range from about 1,200 (RI) to about 41,000 (CA). Models are available in .MB (Maya), .MAX, .3DS and .OBJ 3D file formats.
3D USA is available for $3,995, while models of individual states can be purchased for $295 or $395, depending on the state.