Boundary representation

In solid modeling and computer-aided design, boundary representation (often abbreviated B-rep or BREP) is a method for representing a 3D shape[1] by defining the limits of its volume.

The basic method for BREP was developed independently in the early 1970s by both Ian C. Braid in Cambridge (for CAD) and Bruce G. Baumgart at Stanford (for computer vision).

In the USA Eastman and Weiler were also working on Boundary Representation and in Japan Professor Fumihiko Kimura and his team at Tokyo University also produced their own B-rep modelling system.

Features are the basis of many other developments, allowing high-level "geometric reasoning" about shape for comparison, process-planning, manufacturing, etc.

In a meeting organized by the Computer-Aided Manufacturing International (CAM-I) in 1979 the IGES format was discussed for solid model transfer.

The following Application Integrated Resources (AICs) define boundary models that are constraints of the generic geometric and topological capabilities:

Corsica Coachworks example generated using the B-Rep model. Notice that the surface areas are stitched together.