| Item | SPF | XML | Change | Description | IFC4x2 to IFC4x3_RC1 |
|---|---|---|---|---|
| IfcAlignment2DVerSegTransition | ADDED |
An IfcAlignment2DVerSegTransition is a 2D transition curve using the inherited attributes from IfcAlignment2DVerticalSegment.
| # | Attribute | Type | Cardinality | Description | G |
|---|---|---|---|---|---|
| 8 | StartRadius | IfcPositiveLengthMeasure | ? | The radius of the curve at the start point. If the radius is not provided by a value, i.e. being �NIL� it is interpreted as INFINITE � the StartPoint is at the point, where it does not have a curvature. | X |
| 9 | EndRadius | IfcPositiveLengthMeasure | ? | The radius of the curve at the end point. If the radius is not provided by a value, i.e. being �NIL� it is interpreted as INFINITE � the end point is at the point, where it does not have a curvature. | X |
| 10 | IsStartRadiusCCW | IfcBoolean | Indication of the curve starting counter-clockwise or clockwise. The orientation of the curve is IsCcw=�true�, if the spiral arc goes counter-clockwise as seen from the right side of the curve, or �to the upside", and with IsCcw=�false� if the spiral arc goes clockwise, or �to the downside�. | X | |
| 11 | IsEndRadiusCCW | IfcBoolean | Indication of the curve ending counter-clockwise or clockwise. The orientation of the clothoidal arc is IsCcw=�true�, if the spiral arc goes counter-clockwise as seen from right side of the curve, or �to the upside", and with IsCcw=�false� if the spiral arc goes clockwise, or �to the downside�. | X | |
| 12 | TransitionCurveType | IfcTransitionCurveType | Indicates the specific type of transition curve. | X |
| # | Attribute | Type | Cardinality | Description | G |
|---|---|---|---|---|---|
| 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.
IFC2x3 CHANGE The inverse attribute LayerAssignments has been added. IFC4 CHANGE The inverse attribute LayerAssignment has been restricted to max 1. Upward compatibility for file based exchange is guaranteed. | 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.
IFC2x3 CHANGE The inverse attribute StyledByItem has been added. | X | |
| IfcGeometricRepresentationItem | |||||
| IfcAlignment2DSegment | |||||
| 1 | TangentialContinuity | IfcBoolean | ? | Connectivity between the continuous segments is not enforced per se to be tangential. Setting "TangentialContinuity" to True means that the current segment shall continue with tangential continuity to the previous one. | X |
| 2 | StartTag | IfcLabel | ? | Tag to annotate the start point of the alignment segment. | X |
| 3 | EndTag | IfcLabel | ? | Tag to annotate the end point of the alignment segment. | X |
| IfcAlignment2DVerticalSegment | |||||
| 4 | StartDistAlong | IfcLengthMeasure | Distance along the horizontal alignment, measured along the IfcAlignment2DHorizontal given in the length unit of the global IfcUnitAssignment. | X | |
| 5 | HorizontalLength | IfcPositiveLengthMeasure | Length measured as distance along the horizontal alignment of the segment. | X | |
| 6 | StartHeight | IfcLengthMeasure |
Elevation in Z of the start point relative to the IfcAlignment coordinate system.
NOTE It is strongly advised to not offset the IfcAlignment coordinate system from the project engineering coordinate system. | X | |
| 7 | StartGradient | IfcRatioMeasure |
Gradient of the tangent of the vertical segment at the start point. It is provided as a ratio measure. The ratio is percentage/100 (0.1 is equal to 10%). It has a theoretical range of -∞ < n < ∞ using a ratio measure. The equivalent range measured in degree is -90° < n < 90°.
NOTE For practical application of start gradient, the range of the ratio measure should be within the limits of -1 ≤ n ≤ 1 (equivalent in degree -45° ≤ n ≤ 45°). However larger limits might apply for particular usages.Positive gradient means an increasing height at the start (or uphill), a negative gradient means decreasing height at the start (or downhill). | X | |
| ToVertical | IfcAlignment2DVertical @Segments | S[1:1] | X | ||
| IfcAlignment2DVerSegTransition | |||||
| 8 | StartRadius | IfcPositiveLengthMeasure | ? | The radius of the curve at the start point. If the radius is not provided by a value, i.e. being �NIL� it is interpreted as INFINITE � the StartPoint is at the point, where it does not have a curvature. | X |
| 9 | EndRadius | IfcPositiveLengthMeasure | ? | The radius of the curve at the end point. If the radius is not provided by a value, i.e. being �NIL� it is interpreted as INFINITE � the end point is at the point, where it does not have a curvature. | X |
| 10 | IsStartRadiusCCW | IfcBoolean | Indication of the curve starting counter-clockwise or clockwise. The orientation of the curve is IsCcw=�true�, if the spiral arc goes counter-clockwise as seen from the right side of the curve, or �to the upside", and with IsCcw=�false� if the spiral arc goes clockwise, or �to the downside�. | X | |
| 11 | IsEndRadiusCCW | IfcBoolean | Indication of the curve ending counter-clockwise or clockwise. The orientation of the clothoidal arc is IsCcw=�true�, if the spiral arc goes counter-clockwise as seen from right side of the curve, or �to the upside", and with IsCcw=�false� if the spiral arc goes clockwise, or �to the downside�. | X | |
| 12 | TransitionCurveType | IfcTransitionCurveType | Indicates the specific type of transition curve. | X | |
<xs:element name="IfcAlignment2DVerSegTransition" type="ifc:IfcAlignment2DVerSegTransition" substitutionGroup="ifc:IfcAlignment2DVerticalSegment" nillable="true"/>
<xs:complexType name="IfcAlignment2DVerSegTransition">
<xs:complexContent>
<xs:extension base="ifc:IfcAlignment2DVerticalSegment">
<xs:attribute name="StartRadius" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
<xs:attribute name="EndRadius" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
<xs:attribute name="IsStartRadiusCCW" type="ifc:IfcBoolean" use="optional"/>
<xs:attribute name="IsEndRadiusCCW" type="ifc:IfcBoolean" use="optional"/>
<xs:attribute name="TransitionCurveType" type="ifc:IfcTransitionCurveType" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
ENTITY IfcAlignment2DVerSegTransition
SUBTYPE OF (IfcAlignment2DVerticalSegment);
StartRadius : OPTIONAL IfcPositiveLengthMeasure;
EndRadius : OPTIONAL IfcPositiveLengthMeasure;
IsStartRadiusCCW : IfcBoolean;
IsEndRadiusCCW : IfcBoolean;
TransitionCurveType : IfcTransitionCurveType;
END_ENTITY;
EXPRESS-G diagram
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