Is useful in topography for representing and editing 3D points (by 3DPOLY, SPLINE OR BLOCK entities) and for triangulation, isolines, cross sections and longitudinal profile. It exists a modifiable library for codes and BLOCKs. The coordinates, the code and the position (in 3DPOLY or SPLINE) of the points can be modified interactively. RCAD 1.7 core provides OpenGL real-time orbit, pan, zoom, shading and lighting.