8.8.3.40 IfcSphere
8.8.3.40.1 Semantic definition
The IfcSphere is a Construction Solid Geometry (CSG) 3D primitive. It is a solid where all points at the surface have the same distance from the center point. The inherited Position attribute defines the IfcAxis2Placement3D and provides:
- SELF\IfcCsgPrimitive3D.Position: The location and orientation of the axis system for the primitive.
- SELF\IfcCsgPrimitive3D.Position.Location: The center of the sphere.
- SELF\IfcCsgPrimitive3D.Position.Position[3]: The z axis points at its positive direction towards the north pole, and by its negative directions towards the south pole.
![sphere](../figures/ifcsphere-layout1.png)
Texture Use Definition
Textures are aligned facing upright with origin at the back (+Y direction) revolving counter-clockwise. Textures are stretched or repeated to the extent of the circumference at the equator according to RepeatS and RepeatT.
Figure 8.8.3.40.B illustrates default texture mapping with a clamped texture (RepeatS=False and RepeatT=False). The image on the left shows the texture where the S axis points to the right and the T axis points up. The image on the right shows the texture applied to the geometry where the X axis points back to the right, the Y axis points back to the left, and the Z axis points up.
![texture](../figures/ifcsphere-texture.png)
Side | Normal | Origin X | Origin Y | Origin Z | S Axis | T Axis |
---|---|---|---|---|---|---|
Side | +Y | 0 | +Radius | 0 | (-X, then curving counter-clockwise) | (+Z, then curving towards top) |
8.8.3.40.2 Entity inheritance
-
- IfcCsgPrimitive3D
- IfcAnnotationFillArea
- IfcBooleanResult
- IfcBoundingBox
- IfcCartesianPointList
- IfcCartesianTransformationOperator
- IfcCurve
- IfcDirection
- IfcFaceBasedSurfaceModel
- IfcFillAreaStyleHatching
- IfcFillAreaStyleTiles
- IfcGeometricSet
- IfcHalfSpaceSolid
- IfcLightSource
- IfcPlacement
- IfcPlanarExtent
- IfcPoint
- IfcSectionedSpine
- IfcSegment
- IfcShellBasedSurfaceModel
- IfcSolidModel
- IfcSurface
- IfcTessellatedItem
- IfcTextLiteral
- IfcVector
8.8.3.40.3 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. |
|
IfcCsgPrimitive3D (2) | |||
1 | Position | IfcAxis2Placement3D |
The placement coordinate system to which the parameters of each individual CSG primitive apply. |
* | Dim | IfcDimensionCount |
This attribute is formally derived.
The space dimensionality of this geometric representation item, it is always 3. |
Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes | |||
IfcSphere (1) | |||
2 | Radius | IfcPositiveLengthMeasure |
The radius of the sphere. |
8.8.3.40.4 Formal representation
ENTITY IfcSphere
SUBTYPE OF (IfcCsgPrimitive3D);
Radius : IfcPositiveLengthMeasure;
END_ENTITY;