IfcSphere

Definition from ISO/CD 10303-42:1992: A sphere is a CSG primitive with a spherical shape defined by a centre and a radius.

Definition from IAI: The inherited Position attribute defines the IfcAxisPlacement3D 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 positve direction towards the north pole, and by its negative directions towards the south pole.


The sphere is positioned within its own placement coordiante system. The origin is the center of the sphere.
When a texture is applied to a sphere, the texture covers the entire surface, wrapping counterclockwise from the back of the sphere (i.e., longitudinal arc intersecting the +Y axis) when viewed from the top of the sphere. The texture has a seam at the back where the X=0 plane intersects the sphere and Y values are positive. Texture Transform affects the texture coordinates of the Sphere NOTE see the Extensible 3D (X3D) definition for textures, please note, that all extrusions in IFC are into the positve z axis, whereas in X3D there are into the positive y axis.

NOTE Corresponding STEP entity: sphere, the position attribute, including the centre point, has been promoted to the immediate supertype IfcCsgPrimitive3D. Please refer to ISO/IS 10303-42:1994, p. 175 for the final definition of the formal standard.

HISTORY New entity in IFC2x Edition 3.

EXPRESS specification:

ENTITY IfcSphere

SUBTYPE OF (

IfcCsgPrimitive3D);

Radius

IfcPositiveLengthMeasure;

END_ENTITY;

Attribute definitions:

Radius

Inheritance graph

ENTITY IfcSphere;

ENTITY IfcRepresentationItem;

INVERSE

LayerAssignments

SET OF IfcPresentationLayerAssignment FOR AssignedItems;

StyledByItem

SET [0:1] OF IfcStyledItem FOR Item;

ENTITY IfcGeometricRepresentationItem;

ENTITY IfcCsgPrimitive3D;

Position

IfcAxis2Placement3D;

DERIVE

Dim

IfcDimensionCount := 3;

ENTITY IfcSphere;

Radius

IfcPositiveLengthMeasure;

END_ENTITY;