IFC 4.3.0.1 (IFC4X3) development

8.20.3.10 IfcFaceSurface

8.20.3.10.1 Semantic definition

The IfcFaceSurface defines the underlying geometry of the associated surface to the face.

Informal Propositions:

  1. The domain of the face surface is formally defined to be the domain of its face geometry as trimmed by the loops, this domain does not include the bounding loops.
  2. A face surface has non zero finite extent.
  3. A face surface is a manifold.
  4. A face surface is arcwise connected.
  5. A face surface has surface genus 0.
  6. The loops are not part of the face domain.
  7. Loop geometry shall be consistent with face geometry. This implies that any edge - curves or vertex points used in defining the loops bounding the face surface shall lie on the face geometry.
  8. The loops of the face shall not intersect.

8.20.3.10.2 Entity inheritance

8.20.3.10.3 Attributes

# Attribute Type Description
IfcRepresentationItem (2)
LayerAssignment SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems

Assignment of the representation item to a single or multiple layer(s). The LayerAssignments can override a LayerAssignments of the IfcRepresentation it is used within the list of Items.

StyledByItem SET [0:1] OF IfcStyledItem FOR Item

Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.

IfcFace (2)
1 Bounds SET [1:?] OF IfcFaceBound

Boundaries of the face.

HasTextureMaps SET [0:?] OF IfcTextureMap FOR MappedTo

No description available.

Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes
IfcFaceSurface (2)
2 FaceSurface IfcSurface

The surface which defines the internal shape of the face. This surface may be unbounded. The domain of the face is defined by this surface and the bounding loops in the inherited attribute SELF\FaceBounds.

3 SameSense IfcBoolean

This flag indicates whether the sense of the surface normal agrees with (TRUE), or opposes (FALSE), the sense of the topological normal to the face.

Table 8.20.3.10.A

8.20.3.10.4 Formal representation

ENTITY IfcFaceSurface
 SUPERTYPE OF (ONEOF
	(IfcAdvancedFace))
 SUBTYPE OF (IfcFace);
	FaceSurface : IfcSurface;
	SameSense : IfcBoolean;
END_ENTITY;

8.20.3.10.5 References

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8.20.3.10.6 Changelog

  • attribute SameSense type, Changed from "boolean" to "IfcBoolean"