Mechanical Modeler

What is the Part Feature?

The Part feature is the highest feature in a Part document [Fig.1].

Fig.1: The Part Feature 

The Part feature is an instance of the MechanicalPart StartUp. The following diagram [Fig.2] shows this StartUp in the partial view of the mechanical StartUps [5] tree. 

Fig.2: The MechanicalRoot Architecture

At the top there is the MechanicalFeature StartUp. All the mechanical features derive from this StartUp. The MechanicalPart StartUp derives from the MechanicalRoot StartUp such as the HybridBody, the GSMTool, and the Sketch StartUps. The first two StartUps define the geometrical features sets described in the referenced article [2].

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Part Feature Contents

The Part feature contains the design of the object to be built. It aggregates (directly or indirectly) all the mechanical features of the Part document (except itself). The following UML schema [Fig.3] describes its contents.

Fig.3: The Part Feature Contents

The Part feature aggregates:

• Three reference planes:

The XY, YZ, YZ planes that together define an origin for the 3D space in which the Part is defined. 

• PartBody, Body, Geometrical Set and Ordered Geometrical Set 

These are called the geometrical features sets. The PartBody (HybridBody) represents the main set. It is automatically created at the Part document creation and cannot be deleted. To enhance the clarity of the design or to facilitate its creation one can offset in other set sub-parts of the design. These other sets are Body features (HybridBody), Geometrical Set (GSMTool), and Ordered Geometrical Set (GSMTool) [2].

• The MechanicalSet: this set is dedicated to aggregate non geometrical features (i.e. MechanicalElement and MechanicalSet) [6].

Retrieving the Part Feature

The Part feature is retrievable thanks to the CATIPrtContainer (MecModInterfaces) interface implemented on the specification container.

  ...
  CATISpecObject_var spSpecObjectOnPart = pIPrtCont->GetPart();
  ...

where pIPrtCont is the CATIPrtContainer interface pointer on the specification container. Refer to the "Specification Container" section in the "Structure of the Part Document" article [1] to see how to retrieve this pointer.

Retrieving the Reference Planes

Once you have a pointer on the Part, you can retrieve its reference planes using the CATIPrtPart  interface (MecModInterfaces).

  ...
  CATIPrtPart * pIPrtPart = NULL ;
  spSpecObjectOnPart->QueryInterface(IID_CATIPrtPart,(void**) & pIPrtPart ) ;
  CATListValCATISpecObject_var ListRefPlanes = pIPrtPart ->GetReferencePlane();
  ...

ListRefPlanes contains three features which implement the CATIGSMPlane (GSMInterfaces) interface.

The Current Feature

The current feature is the current mechanical feature that you can interactively change with the "Define Object in Work" command. The available interface to retrieve or set the current feature is the CATIPrtPart interface.

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In Short

The specification container is one of the containers of the Part document. It groups together the mechanical features. One of these is the Part feature. It represents the end user design. It aggregates all the other mechanical features of the Part document.

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References

History

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