Cad Data Transfer for Solid Models

Project Overview.- The Transfer of Solid Models.- 1. Introduction.- 1.1 The evolution of concepts and specifications for CAD data exchange.- 1.1.1 IGES.- 1.1.2 Other standards: VDAFS and SET.- 1.1.3 The need for a new standard.- 1.2 Solid modelling techniques.- 2. The CAD*I approach to solid model transfer.- 2.1 General principles.- 2.2 The specification tools.- 2.2.1 Features of the CAD*I specification language HDSL.- 2.2.2 The specification language for the physical file format.- 2.3 Specification of the CAD*I reference model.- 2.3.1 Content.- 2.3.1.1 Attribute types for general use.- 2.3.1.2 General data base structure.- 2.3.1.3 Referencing mechanisms.- 2.3.1.4 Geometric model entities.- 2.3.1.5 Solid models.- 2.3.1.6 General grouping mechanism.- 2.3.1.7 Test data elements.- 2.3.1.8 Miscellaneous.- 2.3.1.9 Parametric modelling.- 2.3.2 Static models and parametric models.- 2.4 Implementation levels.- 2.4.1 The geometric modelling levels.- 2.4.2 The assembly structure.- 2.4.3 Parametric models and macros.- 2.4.4 References.- 2.5 The specification of semantic meaning.- 2.5.1 Generic semantics of the CAD.' data structures.- 2.5.1.1 Creation of data structure elements.- 2.5.1.2 Deletion of data structure elements.- 2.5.1.3 Modification of attributes.- 2.5.1.4 Navigation in the data structure.- 2.5.2 The semantics of post-processors.- 2.5.3 The static semantics of geometric entities.- 2.5.3.1 Curves and surfaces.- 2.5.3.2 Solids.- 2.5.4 Linear transformation of geometric models.- 2.6 Aspects of the physical file format.- 2.6.1 The transport aspect.- 2.6.2 The presentation aspect.- 2.7 Processor implementation.- 2.8 Access to CAD system data bases.- 3. General implementation problems.- 3.1 Access to the CAD system data base.- 3.1.1 Programming interface.- 3.1.2 Access via files.- 3.2 Mapping problems.- 3.3 Inference of the original meaning: Euclid primitives.- 3.4 Missing CAD*I entity example: Pyramid in Bravo3.- 3.5 Implicit model conversion example: CSG input to a B-rep system.- 3.6 Deviations from the reference model: The Bravo3 one-sided Boolean tree.- 3.7 The overlap problem in CSG modelling: a Bravo3 example.- 3.8 Problems related to Boolean operations in Proren2 and Technovision.- 3.9 The effect of truncation errors: receiving boxes in Bravo3.- Specific Implementations.- 4. The CAD*I processors for Schlumberger's Bravo3.- 4.1 System description.- 4.2 Internal representation of CAD models.- 4.3 Existing interfaces.- 4.4 Embedding the processors into the Bravo3 environment.- 4.5 The pre-processor.- 4.5.1 Instances.- 4.5.2 Names.- 4.5.3 Features.- 4.5.4 The mapping from Bravo design input to CAD*I format.- 4.6 Examples of pre-processor conversions.- 4.6.1 Parallelepiped.- 4.6.2 Polyhedron.- 4.6.3 Right Angle Wedge.- 4.6.4 Sphere.- 4.6.5 Right Circular Cylinder.- 4.6.6 Truncated Right Cone.- 4.6.7 Solid Torus.- 4.6.8 Arbitrary Slab.- 4.6.9 Surface of revolution.- 4.7 The post-processor.- 4.8 Examples of post-processor conversions and approximations.- 4.8.1 Examples of the command input file.- 4.8.2 Some details to post-processor transactions.- 4.8.3 Special features.- 4.9 The formal Bravo3 solid model transfer schema.- 4.9.1 Pre-processor schema.- 4.9.1.1 General data base structure.- 4.9.1.2 Points and curves.- 4.9.1.3 Constructive solid geometry.- 4.9.1.4 General grouping mechanism.- 4.9.1.5 Placement and instancing.- 4.9.1.6 Miscellaneous.- 4.9.2 Post-processor.- 4.9.2.1 General data base structure.- 4.9.2.2 Points and curves.- 4.9.2.3 Constructive solid geometry.- 4.9.2.4 General grouping mechanism.- 4.9.2.5 Placement and instancing.- 4.10 Test results.- 5. The CAD*I processors for IBM's Catia.- 5.1 System description.- 5.2 Existing interfaces.- 5.3 Internal representation of CAD models.- 5.4 Embedding the processors in the Catia environment.- 5.4.1 Hardware and operating system.- 5.4.2 Programming Language and Compiler.- 5.4.3 CATGEO routines to access the Catia database.- 5.4.4 Standardisation of routine names.- 5.4.5 Internal programme documentation.- 5.5 The pre-processor.- 5.5.1 Implementation levels.- 5.5.2 The formal Catia solid model transfer schema.- 5.5.3 Programme description.- 5.6 The post-processor.- 5.6.1 Implementation levels.- 5.6.2 The formal Catia solid model transfer schema.- 5.6.3 Programme description.- 5.7 Test results.- 6. The CAD*I processors for Matra Datavision's Euclid.- 6.1 System description.- 6.2 Existing interfaces.- 6.3 Internal representation of CAD models.- 6.4 Embedding the processors into the Euclid environment.- 6.4.1 Pre-processor.- 6.4.2 Post-processor.- 6.5 The mapping from Euclid data structure to CAD*I data structure.- 6.5.1 Processing of Euclid solid primitives.- 6.5.1.1 Processing of the Euclid solid of revolution.- 6.5.1.2 Processing of special cases of Euclid polyhedron entities (BOX).- 6.5.1.3 Processing of general Euclid polyhedron entities.- 6.5.2 The processing of Euclid hybrid solids.- 6.5.3 The processing of the Euclid "figure" entities.- 6.6 The mapping from CAD*I data structure to Euclid data structure.- 6.6.1 Processing of information related to the neutral file.- 6.6.2 Processing of information related to the world.- 6.6.3 Processing of elementary geometric information.- 6.6.4 Processing of composite geometric information.- 6.6.4.1 Mapping of sweep entities to Euclid representations.- 6.6.4.2 Mapping of polyhedron entities to the Euclid polyhedron.- 6.6.5 Processing of structural information.- 6.7 Mapping problems in the pre-processor.- 6.7.1 Mapping problems with the Euclid primitives.- 6.7.2 Mapping problems with Boolean expressions in Euclid.- 6.7.3 Mapping problems with polyhedron entities in Euclid.- 6.8 Mapping problems in the post-processor.- 6.9 Possible enhancements of the processors.- 6.10 Test results.- 7. The CAD*I processors for DTH's GDS.- 7.1 System description.- 7.2 User interaction and internal representation.- 7.3 Existing interfaces.- 7.4 The pre-processors.- 7.4.1 The data base traversal.- 7.4.2 Limitations.- 7.5 An example of pre-processor conversion.- 7.6 The post-processors.- 7.6.1 The data structure.- 7.7 An example of post-processor conversion.- 8. The CAD*I processors for SDRC's Geomod.- 8.1 System description.- 8.2 Existing interfaces.- 8.2.1 IGES.- 8.2.2 Universal file.- 8.2.3 Programme files (log file).- 8.2.4 PEARL data base interface (PDI).- 8.2.5 Internal representation of CAD models.- 8.2.6 Object Representation.- 8.2.7 Polygonal model.- 8.2.8 Context-free geometry.- 8.2.9 Grouping data.- 8.3 The pre-processor.- 8.4 The post-processor.- 8.4.1 General concept.- 8.4.2 Generation of CSG Models.- 8.4.3 Generation of B-rep models.- 9. The CAD*I processors for Control Data's Item.- 9.1 System description.- 9.2 Internal representation of CAD models.- 9.3 Existing interfaces.- 9.4 Embedding the processors into the Icem Modeller environment.- 9.5 The pre-processor.- 9.6 Examples of pre-processor conversions.- 9.6.1 Parallelepiped.- 9.6.2 Arbitrary polyhedron.- 9.6.3 Truncated right cone.- 9.6.4 Solid-cylinder.- 9.6.5 Sphere.- 9.6.6 Solid Torus.- 9.7 The post-processor.- 9.7.1 Examples of post-processor conversions and approximations.- 9.7.2 Special implementation features.- 9.8 Test results.- 10. The CAD*I processors for Isykon's Proren2.- 10.1 System description.- 10.2 Existing interfaces.- 10.3 Internal representation of CAD models.- 10.3.1 The formal description of the internal model.- 10.3.2 The formal description of the CSG input language.- 10.3.2.1 The relation between CAD*I and Proren primitives.- 10.3.2.2 The operators.- 10.4 The B-rep pre-processor.- 10.4.1 Some problems in the pre-processor area.- 10.4.1.1 Pre-processor and geometrical problems.- 10.5 The post-processor for B-rep and polyhedron models.- 10.6 The post-processor for CSG models.- 10.7 Embedding the processors into the Proren2 environment.- 10.8 Test results.- 11. The CAD*I processors for Shape Data's Romulus.- 11.1 System description.- 11.2 Existing interfaces.- 11.3 Mapping between CAD*I and Romulus.- 11.4 The processors.- 11.4.1 The pre-processor.- 11.4.2 The post-processor.- 11.4.3 Parsing the neutral file.- 11.4.4 Creating geometry.- 11.4.5 The temporary data structure.- 11.5 Concluding remarks.- 12. The CAD*I processors for Norsk Data's Technovision.- 12.1 System description.- 12.2 User interaction and internal representation.- 12.3 Existing interfaces.- 12.4 The processors.- 12.4.1 Pre-processors.- 12.4.2 Post-processors.- 12.4.3 Implementation levels.- 12.5 Pre-processor architecture and implementation.- 12.6 Post-processor architecture and implementation.- 12.7 Program design and implementation strategies.- 12.8 Performance and other measurements on the CAD*I pre- and post-processors for Technovision.- 12.9 An example of a transfer test Technovision ? Proren ? Technovision.- 13. The CAD*I/STEP converters.- 13.1 CAD*I and STEP files for the CAD*I/STEP conversion test.- 14. Other implementations.- 14.1 Kismet.- 14.2 Bravo3 ROBOT.- 14.3 ROBCAD.- 14.4 Autocad.- 14.5 Oracle.- 14.6 GRASP.- 14.7 Weld Planning Module.- Software Development Tools and Test Parts.- 15. The CAD*I software tools.- 15.1 General architecture of pre- and post-processors.- 15.2 Common file access software for pre-processors.- 15.2.1 Files and common areas.- 15.2.2 Routine specification.- 15.3 The front-end of the CAD*I post-processors.- 15.3.1 Scanner.- 15.3.2 Parser.- 15.3.3 Type checking.- 15.4 Utility Software: The CADI metafile handler.- 16. The CAD*I test parts.- 16.1 Introduction.- 16.2 Classification of test parts.- International Standardisation.- 17. The interaction of CAD*I with ISO/TC184/SC4/WG1.- 17.1 Scope of the specification.- 17.2 Three-layer approach.- 17.3 Integration versus coexistence.- 17.4 The specification language.- 17.5 The neutral file format.- 17.6 CAD geometry and shape representation.- 17.6.1 Curves and surfaces.- 17.6.2 Solid models.- Transfer of CAD Files Via Computer Networks.- 18. Networks for communicating CAD information.- 18.1 Communication in general.- 18.2 Application of file transfer for CAD.- 18.2.1 Scope of feasibility study.- 19. Overview on available networks and protocols.- 19.1 Introduction.- 19.2 Networks.- 19.2.1 Public Data Networks.- 19.2.2 Local Area Networks.- 19.2.3 Academic and Research Networks.- 19.2.3.1 European Academic and Research Network (EARN).- 19.2.3.2 Associate Networks for European Research (RARE).- 19.3 Network protocols.- 19.3.1 KERMIT.- 19.3.2 Rechner Verbund System (RVS).- 19.3.3 TCP/IP Networking Protocol.- 19.4 Standards and specification work.- 19.4.1 File Transfer, Access and Management (FTAM).- 19.4.2 Message Handling System (MHS).- 19.4.3 Manufacturing Automation Protocol (MAP).- 19.4.4 Technical and Office Protocol (TOP).- 19.4.5 Communications Network for Manufacturing Applications (CNMA).- 19.4.6 Deutsches Forschungsnetz (DFN).- 19.4.7 Conformance Testing Services (CTS).- 19.4.8 Communication Architecture for Layered Open Systems (CARLOS).- 20. The CAD*I network.- 20.1 Established network connections.- 20.1.1 Bayerische Motorenwerke AG.- 20.1.2 Cranfield Institute of Technology.- 20.1.3 Danmarks Tekniske Hojskole.- 20.1.4 Kernforschungszentrum Karlsruhe GmbH.- 20.2 File transfer test software "CADINE".- 21. Results of the networking experiments.- 21.1 Networks.- 21.1.1 Public Data Networks.- 21.1.2 Local Area Networks.- 21.1.3 Academic and Research Networks.- 21.2 Network protocols.- 21.2.1 KERMIT.- 21.2.2 RVS (Rechner Verbund System).- 21.2.3 File Transfer based on FTAM.- 21.2.4 Message Handling System X.400.- 22. The CAD*I metafile utility.- 22.1 A future CAD data exchange environment based on FTAM.- 22.2 The application process.- 22.3 The application interface.- 22.3.1 The OSI environment.- 22.3.2 The real system environment.- 23. Summary of network investigations.- A New Specification Technique for CAD Models.- 24. Algebraic data types: a new approach to specifying CAD models.- 24.1 Introduction.- 24.2 Constructors, attributes, relations, modifiers.- 24.3 Introduction to important concepts of algebra.- 24.3.1 Object specifications.- 24.3.2 Algebraic specification for data base implementations.- 24.4 Algebraic specification for model conversion in CAD data exchange.- 24.5 A minimal geometric model specification example.- 24.5.1 Points and circle with HDSL.- 24.5.2 Points and circle with EXPRESS.- 24.5.3 Points and circle with ASN.1.- 24.5.4 Points and circle in an algebraic specification.- 24.6 Comparison of specification capabilities.- 24.7 Algebraic specification of CAD models.- References.- Appendix A. Three different types of standards.- A.1 Types of standards.- A.2 Introduction to function standards.- Appendix B. List of frequently used abbreviations.