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Application module:
Manifold surface |
ISO/TS 10303-1509:2018-11(E)
© ISO
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This clause specifies the information requirements for the
Manifold surface
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
Manifold_surface_arm
schema and identifies the necessary external references.
EXPRESS specification:
*)
SCHEMA Manifold_surface_arm;
(*
The following EXPRESS interface statement specifies the elements
imported from the ARM of another application module.
EXPRESS specification:
*)
USE FROM
Topologically_bounded_surface_arm;
--
ISO/TS 10303-1511
(*
NOTE 1
The schemas referenced above are specified in the following
part of ISO 10303:
| Topologically_bounded_surface_arm |
ISO/TS 10303-1511 |
NOTE 2
See Annex C,
Figures
C.1and C.2
for a graphical representation of this schema.
This subclause specifies the ARM type
for this application module. The ARM type and
definition is specified below.
A SELECT type defining the types of element that are to be used in the definition of a Manifold_surface_shape_representation
EXPRESS specification:
*)
TYPE
manifold_surface_shape_representation_item =
SELECT
(Axis_placement_3d,
Geometric_placement_operation,
Shell_based_surface_model);
END_TYPE;
(*
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.
A Manifold_surface_shape_representation is a type of
Geometric_model
that consists of one or many shell-based surface models, and transformations, if needed.
Each shell-based surface model is built up of open or closed shells and which are connected sets of faces.
NOTE 1
This entity is incompletely modeled in the ARM. Complete specification
can be obtained in the definition of the corresponding MIM entity.
NOTE 2
Although this only appears in the MIM schema, the faces included in shell-based surface models are Advanced_face.
EXPRESS specification:
*)
ENTITY Manifold_surface_shape_representation
SUBTYPE OF (Geometric_model);
SELF\Representation.items : SET[1:?] OF manifold_surface_shape_representation_item;
END_ENTITY;
(*
Attribute definitions:
items:
a set of
manifold_surface_shape_representation_items
that belongs to a collection defined by the Manifold_surface_shape_representation. Each item is a Shell_based_surface_model, or an Axis_placement_3d,
or a Geometric_placement_operation.
NOTE 3
When a Geometric_placement_operation is included there are
rules in the corresponding MIM entity to ensure that it is mapping a Manifold_surface_shape_representation.
An Open_shell is a type of
Connected_face_set that is a shell defined by a collection of faces and containing at least one hole.
EXPRESS specification:
*)
ENTITY Open_shell
SUBTYPE OF (Connected_face_set);
END_ENTITY;
(*
Informal propositions:
IP1:
every edge shall be referenced at least once, but no more than twice by the bounds of the
shell.
IP2:
each Oriented_edge reference shall be unique.
IP3:
One or more Edges of the faces of the shell shal only be referenced once. This ensures that the shell is not closed.
A Shell_based_surface_model is a type of
Detailed_geometric_model_element that is a collection of shells.
EXPRESS specification:
*)
ENTITY Shell_based_surface_model
SUBTYPE OF (Detailed_geometric_model_element);
boundary : SET[1:?] OF Connected_face_set;
END_ENTITY;
(*
Attribute definitions:
boundary:
a set of
Connected_face_sets
that the Shell_based_surface_model is a collection of. Each is required to be either either an Open_shell, or to have the form of a closed shell.
Informal propositions:
IP1:
every edge shall be referenced at least once, but no more than twice by the bounds of the
faces of the boundary. This ensures that the boundary is a collection of Open_shells, or, if all edges are referenced twice, of closed shells.
IP2:
each Oriented_edge reference shall be unique.
*)
END_SCHEMA; -- Manifold_surface_arm
(*
© ISO 2018 — All rights reserved
