8.9.3.55 IfcRectangularTrimmedSurface
8.9.3.55.1 Semantic definition
The IfcRectangularTrimmedSurface is a surface created by bounding its BasisSurface along two pairs of parallel curves defined within the parametric space of the referenced surface.
{ .extDef}
Informal Propositions
- The domain of the trimmed surface shall be within the domain of the surface being trimmed.
8.9.3.55.2 Entity inheritance
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- IfcSurface
- IfcAnnotationFillArea
- IfcBooleanResult
- IfcBoundingBox
- IfcCartesianPointList
- IfcCartesianTransformationOperator
- IfcCsgPrimitive3D
- IfcCurve
- IfcDirection
- IfcFaceBasedSurfaceModel
- IfcFillAreaStyleHatching
- IfcFillAreaStyleTiles
- IfcGeometricSet
- IfcHalfSpaceSolid
- IfcLightSource
- IfcPlacement
- IfcPlanarExtent
- IfcPoint
- IfcSectionedSpine
- IfcSegment
- IfcShellBasedSurfaceModel
- IfcSolidModel
- IfcTessellatedItem
- IfcTextLiteral
- IfcVector
8.9.3.55.3 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. |
|
| IfcSurface (1) | |||
| * | Dim | IfcDimensionCount |
This attribute is formally derived. The space dimensionality of IfcSurface. It is always a three-dimensional geometric representation item. |
| Click to show 3 hidden inherited attributes Click to hide 3 inherited attributes | |||
| IfcRectangularTrimmedSurface (7) | |||
| 1 | BasisSurface | IfcSurface |
Surface being trimmed. |
| 2 | U1 | IfcParameterValue |
First u parametric value. |
| 3 | V1 | IfcParameterValue |
First v parametric value. |
| 4 | U2 | IfcParameterValue |
Second u parametric value. |
| 5 | V2 | IfcParameterValue |
Second v parametric value. |
| 6 | Usense | IfcBoolean |
Flag to indicate whether the direction of the first parameter of the trimmed surface agrees with or opposes the sense of u in the basis surface. |
| 7 | Vsense | IfcBoolean |
Flag to indicate whether the direction of the second parameter of the trimmed surface agrees with or opposes the sense of v in the basis surface. |
8.9.3.55.4 Formal propositions
| Name | Description |
|---|---|
| U1AndU2Different |
U1 and U2 shall have different values. |
|
|
| UsenseCompatible |
With exception of those surfaces closed in the U parameter, direction Usense shall be compatible with the ordered parameter values for U. |
|
|
| V1AndV2Different |
V1 and V2 shall have different values. |
|
|
| VsenseCompatible |
Vsense shall be compatible with the ordered parameter values for V. |
|
|
8.9.3.55.5 Formal representation
ENTITY IfcRectangularTrimmedSurface
SUBTYPE OF (IfcBoundedSurface);
BasisSurface : IfcSurface;
U1 : IfcParameterValue;
V1 : IfcParameterValue;
U2 : IfcParameterValue;
V2 : IfcParameterValue;
Usense : IfcBoolean;
Vsense : IfcBoolean;
WHERE
U1AndU2Different : U1 <> U2;
UsenseCompatible : (('IFC4X4_DEV_20260525.IFCELEMENTARYSURFACE' IN TYPEOF(BasisSurface)) AND
(NOT ('IFC4X4_DEV_20260525.IFCPLANE' IN TYPEOF(BasisSurface)))) OR
('IFC4X4_DEV_20260525.IFCSURFACEOFREVOLUTION' IN TYPEOF(BasisSurface)) OR
(Usense = (U2 > U1));
V1AndV2Different : V1 <> V2;
VsenseCompatible : Vsense = (V2 > V1);
END_ENTITY;
