Methodologies and Advice

This section provides information regarding supported features and limitations when using Acis/DXF 3D/Inventor/VDA-FS data in CATIA V5, that you should be familiar with prior to configuring and using MULTICAx AD Plug-in. It also offers advice regarding the conditions under which these technologies should be used.
 

Output Formats

Importing Multi-CAD data into V5 results in a conversion of the imported data to one of three formats, selectable by the user. Depending on how the imported data will be used, you can choose whether to create CGR, CGR with canonical information or CATPart data.
Each of these formats allows access to part user attributes (via the Edit->Properties menu command): 

  • Move the data (cf. limitations to move due to the associative mode)
  • Clash detection
  • Inertia and volume calculations

Each format has its own limitations and advantages:

  • CGR (Visu mode). CATIA Graphical Representation is the visualization format of CATIA V5. With this very light format, you can do approximate measurement and have access to all the basic DMU functionalities.
  • CGR with canonical information which enable exact measurement and exact snapping (Visu Snap mode)
  • CATPart (CATPart mode). It is a standard V5 CATPart which is locked, therefore you can use it as any other CATPart with the exception that you cannot modify it. You can just reference it.

Supported Features

  • Access to part user attributes (via Edit -> Properties)
  • Move
  • Exact positioning - Snap command - when using CATPart Mode
  • Clash detection
  • Approximate measurements (or exact measurement with CATPart)
  • Inertia and volume calculations

General warning about CAD converters

V5 MultiCAD converters provide the best effort to match external CAD data and produced V5 data.
However, due to various implementation choices and specific data models used by each CAD actor on the market, MultiCad direct solutions cannot guarantee that produced data perfectly matches original data at anytime in every possible situation.
STEP is an international standard dedicated to interoperability. Each CAD system export from STEP or Import from STEP with a common certified specification which warranty the highest rates of reliability, of conformance and accuracy.
Multi-Cad direct CAD to V5 solutions are the shortest and easiest way to proceed but may include some restrictions that customer must be aware of.
For support of sensitive customer process, it should be considered to use STEP(ST1) or Multi-Cad STEP (DTL) as an alternative solution when Multi-Cad direct CAD to V5 does not apply.

Limitations

  • There is a size limitation for external CAD data and the import of large files may fail with the following message (for a .sat file): Conversion of ... .sat failed using Direct Server.
    Split the file into several ones to by-pass this limitation.
  • Coordinate systems are not supported.
  • VDA-FS files which contain POLYGON entity type are not supported.
  • If DXF 3D models contain block references ("AcDbBlockReference" in the file .dxf) and 3D Solid entities, you must remove all the block references before inserting this file in V5.
  • Application specific format (e.g. piping data) is not in the scope of MultiCAD (which is dedicated to Product structure and geometry).
  • If DXF 3D models contain Boundary and Tessellated representations at the same part level, only one representation is converted, depending on the exact mode option.  

Using CATPart Mode vs Visu Mode

The MULTICAx Acis Plug-in supports CATPart mode, allowing Acis/DXF 3D/Inventor/VDA-FS parts to be imported as CATPart data files. In this mode, Acis/DXF 3D/Inventor/VDA-FS parts data contained in the solid body are transferred into a CATPart.
Because CATPart files are large and take more time to convert, the CATPart mode management is an optional feature.

CATPart Features and Limitations

The features and limitations of Multi-CAD CATParts are the same as the ones of locked V5 CATParts, which can be used as a reference but cannot be modified.
Multi-shells entities, i.e. entities with one external shell and one internal shell, are not transferred as such (as a part body) but as a geometrical set containing several faces.

When to use the CATPart mode

CATPart Mode is used when you need to perform exact positioning and exact measuring.
You should be aware that the conversion to the CATPart format requires more time than only generating the CGR (faceted format). In addition, CATPart files are larger than their corresponding CGR files. Therefore, it is recommended that CATPart mode is only enabled if exact positioning, exact measurement or putting constraints is required.