Definition from IAI: Generalization of all existence dependent
elements which modify the shape and appearance of the associated master
element. The IfcFeatureElement offers the ability to handle shape
modifiers as semantic objects within the IFC object model.
NOTE: The term "feature" has a predefined
meaning in a context of "feature-based modeling" and within steel construction
work. It is introduced here in a broad sense to cover all existence dependent,
but semantically described, modifiers of an element's shape and appearance. It
is envisioned that future releases enhance the feature-based capabilities of
the IFC model.
HISTORY: New entity in Release IFC2x
Edition 2.
NOTE: The entity is
introduced as an upward compatible extension of the IFC2x platform. It is an
intermediate abstract supertype without defining its own explicit
attributes.
Geometry Use Definitions:
The geometric representation of IfcFeatureElement is given by the
IfcProductDefinitionShape, allowing multiple geometric representation.
Local Placement
The local placement for IfcEquipmentElement is defined in its
supertype IfcProduct. It is defined by the IfcLocalPlacement,
which defines the local coordinate system that is referenced by all geometric
representations.
- The PlacementRelTo relationship of IfcLocalPlacement
shall point (if given) to the local placement of the master IfcElement
(its relevant subtypes), which is associated to the IfcFeatureElement by
the appropriate relationship object.
- If the relative placement is not used, the absolute placement is
defined within the world coordinate system.
Shape Representation
The geometry use definitions for the shape representation of the
IfcFeatureElement is given at the level of its subtypes.