Definition from IAI: An assignment of one or many surface style
elements to a surface, defined by subtypes of IfcSurface,
IfcFaceBasedSurfaceModel, IfcShellBasedSurfaceModel, or by
subtypes of IfcSolidModel. The positive direction of the surface normal
relates to the positive side. In case of solids the outside of the solid is to
be taken as positive side.
NOTE: The surface style is often referred to as
material definition in rendering applications.
NOTE Corresponding STEP entity:
surface_style_usage and surface_side_style. Please refer to ISO/IS
10303-46:1994 for the final definition of the formal standard. The surface
style definition in regard to support of rendering has been greatly expanded
beyond the scope of ISO/IS 10303-46.
HISTORY New Entity in IFC
2.x.