Prototyping is an essential step in the manufacture of many objects, both consumer and industrial. A fundamental step in this process is the definition of the 3-D form of the object shape, for example, a designer's model created in clay or wood. A 3-D vision system (range sensor) offers the advantage of speed in defining shapes compared to a traditional tactile sensor. The viability of using range sensors is demonstrated by the development of a rapid prototyping system comprised of a laser-based range sensor and software that creates a computer model of the object. One particularly important area of application is the reverse engineering of models comprised of free-form surfaces. This is important in mold and die manufacture for aerodynamic and ergonomic object surfaces. Several methods of modeling free-form surfaces from irregular data are examined and a radial basis function approach is used in developing a self-contained, interactive software package utilizing the laser-generated range data.