BRep Solid

A Boundary Representation (BRep) solid is a solid volume in 3D space, defined by a collection of closed surfaces. The exterior surface may be represented by any surface type, with the additional requirement that this composite surface must be closed, in order to form a volume.

An BRep solid can contain spatial voids. Each spatial void may be represented by any surface type, representing an interior surface. These surfaces must be closed to form a volume. The concept of voids is analagous to the inner boundaries that define donut holes.

A BRep solid must contain one exterior surface and zero or more interior surfaces.

While it is generally expected that all boundary surfaces are closed to form volumes, no strict restrictions are enforced in the FME storage of solids. If required, transformers may be used to repair unclosed solids.

BRep solids may possess optional front or back appearances, and may be single or double sided.