Defined in File Ifc4x3_rc1.h
IfcSurfaceSide is a denotion of whether negative, positive or both sides of a surface are being referenced.
ENUMERATION Definition from ISO/CD 10303-46:1992:
POSITIVE: The side of a surface which is in the same direction as the surface normal derived from the mathematical definition.
NEGATIVE: The side of a surface which is in the opposite direction than the surface normal derived from the mathematical definition. BOTH: Both, positive and negative side.
NOTE Corresponding ISO 10303 type: surface_side. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
HISTORY: New Enumeration in IFC 2.0