The Finite Volume attribute (0066,000E) shall be YES when the surface mesh generated by the primitives is topologically closed and has an inside and an outside. A surface mesh is closed if it has no rim (every facet has a neighboring facet along each edge). Figure C.27.1.1-1 shows a surface that is not closed on the left, and a closed and waterproof version of the same shape on the right:
Figure C.27.1.1-1 - Finite Volume Illustration
Not all closed surfaces contain a finite volume, for example if the surface self-intersects. Such surfaces do not contain a finite volume. A surface is not required to be contiguous.
A value of NO indicates that the surface is not closed.
A value of UNKNOWN indicates that the transmitting application did not determine if the surface is closed.