Negative Polyhedron Element (NPOLYHEDRON)

Primitive Hole Element

Description

Represents a 3D negative polyhedral volume in terms of sets of points which define the vertices, and hence the edges, of the planar faces (POLFACs) enclosing the volume.

Each POLFAC is defined by one or more planar Polyhedron Loops (POLOOP). Each POLOOP is defined by a sequence of vertex positions which are identified by means of a Loop Points element (LOOPTS). The LOOPTS comprises references to sets of Point (POIN) elements held by administrative Polyhedron Point List (POLPTL) elements.

The intended use of this element is as a means of importing 3D-shape data into DESIGN from external sources, rather than for creating polyhedra directly within DESIGN. Such data would normally be read into DESIGN via a macro file generated elsewhere. For this reason, there is no mechanism for creating Negative Polyhedra or their related elements from the DESIGN applicationware.

Attributes

Legal Owners

Box Element (BOX)

Bent Plate Element (BPANEL)

Cone Element (CONE)

Circular Torus Element (CTORUS)

Cylinder Element (CYLINDER)

Dish Element (DISH)

Extrusion Element (EXTRUSION)

Floor Element (FLOOR)

Wall Element (GWALL)

Panel Element (PANEL)

Polyhedron Element (POLYHEDRON)

Pyramid Element (PYRAMID)

Revolution Element (REVOLUTION)

Rectangular Torus Element (RTORUS)

Screed Element (SCREED)

Slope Bottom Cylinder Element (SLCYLINDER)

Snout Element (SNOUT)

Template Element (TMPLATE)

Terrain Primitive Holder Element (TRNPRI)

Legal Members

Polyhedron Face Element (POLFACE)

Polyhedron Point List Element (POLPTLIST)

The Negative Polyhedron (NPOLYH) is identical to the Solid Polyhedron, (POLYHE; refer to Polyhedron Element (POLYHEDRON)). In principle, except that it is interpreted geometrically as a hole rather than as a solid volume. See the entries following the Solid Polyhedron for details of its constituent elements.