Defined in File Ifc4x1.h
IfcRectangularPyramid: public Ifc4x1::IfcCsgPrimitive3D¶
The IfcRectangularPyramid is a Construction Solid Geometry (CSG) 3D primitive. It is a solid with a rectangular base and a point called apex as the top. The tapers from the base to the top. The axis from the center of the base to the apex is perpendicular to the base. The inherited Position attribute defines the IfcAxisPlacement3D and provides the location and orientation of the pyramid:
SELF\IfcCsgPrimitive3D.Position: The location and orientation of the axis system for the primitive. SELF\IfcCsgPrimitive3D.Position.Location: The center of the circular area being the bottom face of the cone. SELF\IfcCsgPrimitive3D.Position.Position: The z-axis of the inherited placement coordinate system provides the center axis of the IfcRightCircularCone, and the apex is at the Height value applied to the positive direction of the z-axis. The BottomRadius defines the circular base at the xy-plane of the placement coordinate system.
As shown in Figure 260, the pyramid is positioned within its own placement coordinate system. The origin is the center of the bottom rectangle, that lies in the XY plane. The apex lies on the positive z axis at [0, 0, Height].
Figure 260 — Rectangular pyramid geometry
NOTE Corresponding ISO 10303 entity: right_circular_cone, the position attribute has been promoted to the immediate supertype IfcCsgPrimitive3D. No semi_angle attribute, and the radius defines the bottom radius, since only a non-truncated cone is in scope. Please refer to ISO/IS 10303-42:1994, p. 176 for the final definition of the formal standard.
HISTORY New entity in IFC2x3
Texture use definition
On each triangular side face, textures are aligned facing upright. Textures are stretched or repeated to the extent of the base of each face according to RepeatS. Textures are stretched or repeated towards the top point according to Repeat T, where the top point has coordinates of (0.5,1.0) if RepeatT is False.
On the bottom face, textures are aligned facing front-to-back.
Figure 261 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
Left -X 0 +YLength 0 -Y (towards top point)
Right +X 0 +YLength 0 +Y (towards top point)
Front +X 0 0 0 +X (towards top point)
Back +Y +XLength +YLength 0 -X (towards top point)
Bottom -Z +XLength 0 0 -X +Y
Figure 261 — Right circular cone textures
The length of the base measured along the placement X axis. It is provided by the inherited axis placement through SELF\IfcCsgPrimitive3D.Position.P.
The length of the base measured along the placement Y axis. It is provided by the inherited axis placement through SELF\IfcCsgPrimitive3D.Position.P.
The height of the apex above the plane of the base, measured in the direction of the placement Z axis, the SELF\IfcCsgPrimitive3D.Position.P.