IfcPointOnSurface

IfcPointOnSurface是由其定义曲面的两个参数值定义的点。

注：定义根据ISO/CD 10303-42:1992

IfcPointOnSurface是位于参数曲面上的点。该点是通过计算一对特定参数值的曲面来确定的。

注：实体改编自ISO 10303-42中_表面上的点。

IFC2x2中增加的新实体。

非正式提议：

●为u和v指定的参数值不得超出基础曲面的参数范围。

#	Attribute	Type	Cardinality	Description	C
IfcRepresentationItem
	LayerAssignment	IfcPresentationLayerAssignment @AssignedItems	S[0:1]	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.	X
	StyledByItem	IfcStyledItem @Item	S[0:1]	Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.	X
IfcGeometricRepresentationItem
IfcPoint
IfcPointOnSurface
1	BasisSurface	IfcSurface	[1:1]	The surface to which the parameter values relate.	X
2	PointParameterU	IfcParameterValue	[1:1]	The first parameter value of the point location.	X
3	PointParameterV	IfcParameterValue	[1:1]	The second parameter value of the point location.	X
	Dim :=BasisSurface.Dim	IfcDimensionCount	[1:1]	The space dimensionality of this class, determined by the space dimensionality of the basis surface.	X

EXPRESS Specification

ENTITY IfcPointOnSurface
 SUBTYPE OF (IfcPoint);
  BasisSurface : IfcSurface;
  PointParameterU : IfcParameterValue;
  PointParameterV : IfcParameterValue;
 DERIVE
  Dim : IfcDimensionCount := BasisSurface.Dim;
END_ENTITY;