Specification of a CAD * I Neutral File for CAD Geometry

Inhaltsangabeto the Specification.- 1.1 Purpose.- 1.2 The relation between this proposal and STEP.- 1.3 Stucture of the document.- Approach.- Basic principles.- 3.1 Use of formal languages.- 3.2 Informal description of the CAD data schema.- 3.2.1 Entities and attributes.- 3.2.2 References.- 3.2.3 Properties.- 3.2.4 Scope.- 3.2.5 World.- 3.2.6 Assemblies and components.- 3.2.7 Geometry.- 3.2.7.1 Curves and surfaces.- 3.2.7.2 Solids Models.- 3.2.7.3 Instancing and placement.- 3.2.8 User-defined name.- 3.2.9 Libraries and external references.- 3.2.10 Parametric Models and macros.- 3.2.11 User records.- 3.2.12 Grouping mechanisms.- 3.3 The physical level.- 3.3.1 Strictly sequential,free format,block structure.- 3.3.2 Metafiles,letters and alphabets.- 3.4 Validation of the CAD model transfer.- 3.4.1 Validation of the opertational behaviour of the model.- 3.4.2 Validation of the geometry.- Reference Manual.- The high level data specification language HDSL.- 4.1 Type declaration.- 4.2 Predefined types.- 4.2.1 The type Integer.- 4.2.2 The type Real.- 4.2.3 The type Logical.- 4.2.4 The type String.- 4.2.5 The type User_Defined_Name.- 4.2.6 The NIL.- 4.2.7 The D2,D3.- 4.2.8 The type Arithmetic_Expression.- 4.3 Composite types.- 4.3.1 Enumeration types.- 4.3.2 Fixed structures types.- 4.3.3 Lists.- 4.3.4 Classes.- 4.4 The types Reference,Ref_Only.- 4.5 Generic types.- 4.5.1 Parametric enumeration types.- 4.5.2 Parametric structure.- 4.5.3 Parametric lists.- 4.5.4 Parametric classes.- 4.5.5 Variant structures.- 4.5.6 Variant classes.- 4.5.7 Generic structures.- 4.5.8 Generic enumerations.- 4.5.9 Generic classes.- 4.5.10 Generic lists.- 4.6 The predefined function Dimension.- 4.7 Rules applying to building a schema with HDSL.- 4.8 Semantics of reference models defined with HDSL.- 4.8.1 Entering entities.- 4.8.2 Interrogating the information content of the environment.- 4.8.3 Identifying entities by textual means.- 4.8.4 Identifying entities by interacvite picking.- 4.8.5 Identifying properties.- 4.8.6 Creating a new entity.- 4.8.7 Creating a new property or relation.- 4.8.8 Deleting an existing entity.- 4.8.9 Deleting an existing property or relation.- 4.8.10 Modifying values of attributes.- 4.8.11 Invoking a modeling function.- 4.8.12 Invoking evaluation functions.- 4.8.13 Linear transformations.- The CAD*I reference model specification.- 5.1 Attribute types for general use.- 5.1.1 Any.- 5.1.2 Dim.- 5.1.3 Type_ID.- 5.1.4 Update.- 5.1.5 List of predefined values.- 5.2 General data base structure.- 5.2.1 World.- 5.2.2 Assembly.- 5.2.3 Component.- 5.2.4 Part_Library.- 5.2.5 Routine_Library.- 5.3 Referencing mechanisms.- 5.3.1 Index_Entry.- 5.3.2 Ref_External.- 5.3.3 Ref_Part_Library.- 5.3.4 Ref_Any.- 5.4 Geometric model entities.- 5.4.1 Geometric_Model.- 5.4.2 Wireframe_Model.- 5.4.3 Surface_Model.- 5.4.4 Solid_Model.- 5.5 Points and Curves.- 5.5.1 Attribute types related to curves.- 5.5.1.1 Curve_Transition_Code.- 5.5.2 Direction.- 5.5.3 Point.- 5.5.4 Curves classes.- 5.5.4.1 Curve.- 5.5.4.2 Elementary_Curve.- 5.5.4.3 Bounded_Curve.- 5.5.4.4 Closed_Curve.- 5.5.5 Elementary curves.- 5.5.5.1 Line.- 5.5.5.2 Line_Segment.- 5.5.5.3 Circle.- 5.5.5.4 Ellipse.- 5.5.5.5 Hyperbola.- 5.5.5.6 Parabola.- 5.5.5.7 Polygon.- 5.5.5.8 B_Spline_Curve.- 5.5.6 Derived curve entities.- 5.5.6.1 Trimmed_Curve.- 5.5.6.2 Composite_Curve.- 5.5.7 Curves with functional dependency.- 5.5.7.1 Offset_Curve.- 5.6 Surfaces.- 5.6.1 Surface classes.- 5.6.1.1 Surfaces.- 5.6.1.2 Rectangular_Surface.- 5.6.1.3 Elementary_Surface.- 5.6.2 Planar_Surface.- 5.6.3 Spherical_Surface.- 5.6.4 Conical_Surface.- 5.6.5 Cylindrical_Surface.- 5.6.7 B_Spline_Surface.- 5.6.8 Surface_of_Revolution.- 5.6.9 Surface_of_Translation.- 5.6.10 Rectangular_Trimmed_Surface.- 5.6.11 Rectangular_Composite_Surface.- 5.6.12 Curve_Bounded_Surface.- 5.6.13 Offset_Surface.- 5.7 Geometry on surfaces.- 5.7.1 Surface_Curve.- 5.7.2 Classes of curves on surfaces.- 5.7.2.1 Curves_On_Surface.- 5.7.3 Point_On_Surface.- 5.7.4 Curves