8.8.3.40 IfcSphere

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.

Figure 8.8.3.40.A illustrates geometric parameters of the sphere. The sphere is positioned within its own placement coordinate system relative to the object coordinate system. The origin is the center of the sphere. Definition according to ISO/CD 10303-42:1992 A sphere is a CSG primitive with a spherical shape defined by a centre and a radius. Entity adapted from sphere defined in ISO 10303-42. New entity in IFC2x3.

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.

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 8.8.3.40.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 8.8.3.40.D

8.8.3.40.4 Formal representation

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

8.8.3.40.5 References

IfcCsgPrimitive3D