IFC (IFC4X3) development

8.8 IfcGeometricModelResource

8.8.1 Schema definition

The schema IfcGeometricModelResource defines the resources used for geometric model representations. The primary application of this resource is for representation of the shape or geometric form of a product model.

The following is within the scope of the geometric model representation in the current version of the geometric model resource:

  • data describing the precise geometric form of three-dimensional solid objects;
  • constructive solid geometry (CSG) models;
  • definition of half-spaces;
  • creation of solid models by sweeping operations;
  • manifold boundary representation (brep) models;
  • surface models;
  • tessellated models;
  • geometric sets.

The constructive solid geometry models are represented by their component primitives and the sequence of Boolean operations (union, intersection, or difference) used in their construction. The entity which communicates the logical sequence of Boolean operations is the boolean result (IfcBooleanResult) which identifies an operator and two operands. Since the operands can themselves be Boolean results thus enabling nested operations. Swept solids and half-space solids are permissible Boolean operands. The swept solids are the solid of revolution and the solid of linear extrusion. The swept solids are obtained by extruding or sweeping a planar face which may contain holes. The half space solid is essentially defined as a semi-infinite solid on one side of a surface; it may be limited by a box domain.

Brep models are represented by the set of shells defining the exterior or interior boundaries. The faceted brep is restricted to represent breps in which all faces are planar and every loop is a poly loop. For such a solid this entity provides a more efficient form of representation. The shell based surface model, the face based surface model and the geometric set entities do not enforce the integrity checks of the manifold solid brep and can be used for the communication of incomplete models (including two-dimensional models).

8.8.2 Types

  1. IfcBooleanOperand
  2. IfcBooleanOperator
  3. IfcCsgSelect
  4. IfcGeometricSetSelect

8.8.3 Entities

  1. IfcAdvancedBrep
  2. IfcAdvancedBrepWithVoids
  3. IfcBlock
  4. IfcBooleanClippingResult
  5. IfcBooleanResult
  6. IfcBoundingBox
  7. IfcBoxedHalfSpace
  8. IfcCartesianPointList
  9. IfcCartesianPointList2D
  10. IfcCartesianPointList3D
  11. IfcCsgPrimitive3D
  12. IfcCsgSolid
  13. IfcDirectrixDerivedReferenceSweptAreaSolid
  14. IfcExtrudedAreaSolid
  15. IfcExtrudedAreaSolidTapered
  16. IfcFaceBasedSurfaceModel
  17. IfcFacetedBrep
  18. IfcFacetedBrepWithVoids
  19. IfcFixedReferenceSweptAreaSolid
  20. IfcGeometricCurveSet
  21. IfcGeometricSet
  22. IfcHalfSpaceSolid
  23. IfcIndexedPolygonalFace
  24. IfcIndexedPolygonalFaceWithVoids
  25. IfcManifoldSolidBrep
  26. IfcPolygonalBoundedHalfSpace
  27. IfcPolygonalFaceSet
  28. IfcRectangularPyramid
  29. IfcRevolvedAreaSolid
  30. IfcRevolvedAreaSolidTapered
  31. IfcRightCircularCone
  32. IfcRightCircularCylinder
  33. IfcSectionedSolid
  34. IfcSectionedSolidHorizontal
  35. IfcSectionedSpine
  36. IfcSectionedSurface
  37. IfcShellBasedSurfaceModel
  38. IfcSolidModel
  39. IfcSphere
  40. IfcSurfaceCurveSweptAreaSolid
  41. IfcSweptAreaSolid
  42. IfcSweptDiskSolid
  43. IfcSweptDiskSolidPolygonal
  44. IfcTessellatedFaceSet
  45. IfcTessellatedItem
  46. IfcTriangulatedFaceSet
  47. IfcTriangulatedIrregularNetwork

8.8.4 Property Sets

No resources are available in this category.

8.8.5 Quantity Sets

No resources are available in this category.

8.8.6 Functions

  1. IfcPointListDim
  2. IfcTaperedSweptAreaProfiles

8.8.7 Rules

No resources are available in this category.

8.8.8 PropertyEnumerations

No resources are available in this category.

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