ISO-10303-42 Industrial automation systems and integration -- Product data representation and exchange -- Part 42: Integrated generic resource: Geometric and topological representation

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ISO 10303-42:2003 specifies the resource constructs for the explicit geometric and topological representation of the shape of a product. The scope is determined by the requirements for the explicit representation of an ideal product model; tolerances and implicit forms of representation in terms of features are out of scope. The geometry in clause 4 and the topology in clause 5 are available for use independently and are also extensively used by the various forms of geometric shape model in clause 6.

In addition, ISO 10303-42:2003 specifies specialisations of the concepts of representation where the elements of representation are geometric.

The following are within the scope of the geometry schema:

  • definition of points, vectors, parametric curves and parametric surfaces;
  • definition of finite volumes with internal parametrisation;
  • definition of transformation operators;
  • points defined directly by their coordinate values or in terms of the parameters of an existing curve or surface;
  • definition of conic curves and elementary surfaces;
  • definition of curves defined on a parametric surface;
  • definition of general parametric spline curves, surfaces and volumes;
  • definition of point, curve and surface replicas;
  • definition of offset curves and surfaces;
  • definition of intersection curves.

The following are outside the scope of ISO 10303-42:2003:

  • all other forms of procedurally defined curves and surfaces;
  • curves and surfaces which do not have a parametric form of representation;
  • any form of explicit representation of a ruled surface.

NOTE For a ruled surface the geometry is critically dependent upon the parametrisation of the boundary curves and the method of associating pairs of points on the two curves. A ruled surface with B-spline boundary curves can however be exactly represented by the B-spline surface entity.


To find similar documents by classification:

25.040.40 (Industrial process measurement and control)

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Publication Date

Dec. 2, 2014

Committee Number

ISO/TC 184/SC 4