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.

{ .extDef}

{ .use-head} 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 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.

{ .gridtable}

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)

Table C — Texture parameters

8.8.3.40.2 Entity inheritance

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. 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.
	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. IFC2x3-CHANGE The inverse attribute StyledByItem has been added.
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. `3` 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.

Table D

8.8.3.40.4 Formal representation

ENTITY IfcSphere
SUBTYPE OF (IfcCsgPrimitive3D);
Radius : IfcPositiveLengthMeasure;
END_ENTITY;

8.8.3.40.5 References

IfcCsgPrimitive3D