3DIUS contains a comprehensive set of general-purpose representations and procedures that are common to most image understanding systems. Its object-oriented design makes it easy to extend the system to address other image understanding constructs and more specialized applications.
However, 3DIUS also provides many unique capabilities not found in other imaging systems. Photogrammetric registration - involving multiple images, terrain models, and 3D objects - permits wire frames to accurately overlay source imagery. Extensive use of lighting models, terrain elevation data, and camera models facilitates data entry and increases the efficiency of the human operator. Local coordinate systems are transformed automatically to geographic reference systems. High-quality simulated scenes are created by texture-mapping images onto terrain data and adding renderings of cartographic features using depth-buffering and antialiasing techniques. Motion sequences can be created by choosing a series of camera models and rendering the simulated appearance of the scene from each viewpoint.
All these facilities are available as primitives for use by programmers building specialized applications. Strict attention has been paid to enforcing photogrammetric rigor throughout, and to exacting the highest performance from standard hardware.
The system is written in a combination of C and Lucid CommonLisp/CLOS for the Sun Microsystems SPARCstation family of computers. Hardware requirements include a GX or GX+ graphics board, at least 32 MB of RAM, and at least 400 MB of disk storage.