IfcMaterialProfileSetUsage determines the usage of IfcMaterialProfileSet in terms of its location relative to the associated element geometry. The location of a material profile set shall be compatible with the building element geometry (that is, material profiles shall fit inside the element geometry). The rules to ensure the compatibility depend on the type of the building element. For building elements with shape representations which are based on extruded solids, this is accomplished by referring to the identical profile definition in the shape model as in the material profile set.
IfcMaterialProfileSetUsage determines the usage of IfcMaterialProfileSet in terms of its location relative to the associated element geometry. The location of a material profile set shall be compatible with the building element geometry (that is, material profiles shall fit inside the element geometry). The rules to ensure the compatibility depend on the type of the building element. For building elements with shape representations which are based on extruded solids, this is accomplished by referring to the identical profile definition in the shape model as in the material profile set.