Application module: Basic geometric topology ISO/TS 10303-1323:2021(E)
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Cover page
Table of contents
Copyright
Foreword
Introduction
1 Scope
2 Normative references
3 Terms, definitions and abbreviated terms
    3.1 Terms and definitions
    3.2 Abbreviated terms

4 Information requirements
   4.1 Required AM ARMs
   4.2 ARM entity definitions
5 Module interpreted model
   5.1 Mapping specification
   5.2 MIM EXPRESS short listing

A MIM short names
B Information object registration
C ARM EXPRESS-G   EXPRESS-G
D MIM EXPRESS-G   EXPRESS-G
E Computer interpretable listings
F Change history
Bibliography
Index

4 Information requirements

This clause specifies the information requirements for the Basic geometric topology application module. The information requirements are specified as the Application Reference Model (ARM) of this application module.

NOTE 1  A graphical representation of the information requirements is given in Annex C.

NOTE 2  The mapping specification is specified in 5.1. It shows how the information requirements are met by using common resources and constructs defined or imported in the MIM schema of this application module.

This clause defines the information requirements to which implementations shall conform using the EXPRESS language as defined in ISO 10303-11. The following begins the Basic_geometric_topology_arm schema and identifies the necessary external references.

EXPRESS specification:

*)
SCHEMA Basic_geometric_topology_arm;
(*

4.1 Required AM ARMs

The following EXPRESS interface statements specify the elements imported from the ARMs of other application modules.

EXPRESS specification:

*)
USE FROM Basic_geometry_arm;    --  ISO/TS 10303-1652

USE FROM Elemental_topology_arm;    --  ISO/TS 10303-1005
(*

NOTE 1   The schemas referenced above are specified in the following part of ISO 10303:

Basic_geometry_arm ISO/TS 10303-1652
Elemental_topology_arm ISO/TS 10303-1005

NOTE 2   See Annex C, Figures C.1and C.2 for a graphical representation of this schema.

4.2 ARM entity definitions

This subclause specifies the ARM entities for this module. Each ARM application entity is an atomic element that embodies a unique application concept and contains attributes specifying the data elements of the entity. The ARM entities and definitions are specified below.

4.2.1 Edge_curve   EXPRESS-GMapping table

An Edge_curve is a type of Detailed_geometric_model_element and a type of Edge that has its geometry defined by a geometric curve.

EXPRESS specification:

*)
ENTITY Edge_curve
  SUBTYPE OF (Detailed_geometric_model_element, Edge);
  edge_geometry : Curve;
  same_sense : BOOLEAN;
END_ENTITY;
(*

Attribute definitions:

edge_geometry: the Curve defining the geometric shape of the edge.

same_sense: a BOOLEAN variable giving the relationship between the topological sense of the edge and the parametric sense of the curve.

4.2.2 Face_surface   EXPRESS-GMapping table

A Face_surface is a type of Detailed_geometric_model_element and a type of Face that has its geometry defined by a geometric Surface.

NOTE 1   The full semantics of this entity is defined in the corresponding AIM object from ISO 10303-42; this has additional constraints in the form of informal propositions.

EXPRESS specification:

*)
ENTITY Face_surface
  SUBTYPE OF (Detailed_geometric_model_element, Face);
  face_geometry : Surface;
  same_sense : BOOLEAN;
END_ENTITY;
(*

Attribute definitions:

face_geometry: the Surface defining the geometric shape of the Face .

NOTE 2   The full semantics of this attribute is defined in the corresponding AIM object from ISO 10303-42; the AIM entity an additional constraints to ensure that the face_geometry is not of type oriented_surface.

same_sense: a BOOLEAN variable giving the relationship between the topological normal of the Face and the geometric normal to the surface.

4.2.3 Poly_loop   EXPRESS-GMapping table

A Poly_loop is a type of Detailed_geometric_model_element and a type of Loop with straight edges bounding a planar region in space. The poly loop is defined by a list of points that serve as vertices. The poly loop is composed of straight line segments joining a point in the list to the succeeding point in the list. The closing segment is from the last to the first point in the list. The direction of the poly loop is in the direction of the line segments. Unlike the Edge_loop entity, the edges and vertices of the Poly_loop are implicitly defined by the polygon points.

NOTE    The full semantics of this entity is defined in the corresponding AIM object from ISO 10303-42; this has additional constraints in the form of informal propositions including a requirement that the defining points are coplanar.

EXPRESS specification:

*)
ENTITY Poly_loop
  SUBTYPE OF (Detailed_geometric_model_element, Loop);
  polygon : LIST[3:?] OF UNIQUE Cartesian_point;
END_ENTITY;
(*

Attribute definitions:

polygon: a list of three (3) or more Cartesian_points defining the loop. There are no repeated points in this list.

4.2.4 Vertex_point   EXPRESS-GMapping table

A Vertex_point is a type of Detailed_geometric_model_element and a type of Vertex that has its geometry location defined by a point in Cartesian space.

EXPRESS specification:

*)
ENTITY Vertex_point
  SUBTYPE OF (Detailed_geometric_model_element, Vertex);
  vertex_geometry : Point;
END_ENTITY;
(*

Attribute definitions:

vertex_geometry: the geometric Point which defines the position in geometric space of the Vertex.



*)
END_SCHEMA;  -- Basic_geometric_topology_arm
(*


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