Mechanical Design

What You Will Learn With This Use Case

This use case is intended to help you make your first steps in programming with CATIA Assembly Design.
Its main intent is to create geometrical relations between products. More specifically, you will learn how to:

• Loading document in session
• Creating a connector
• Creating a constraint

Before getting to the use case itself, it is important to get an understanding of some of the Product Structure concepts that are at the heart of the Assembly Design.

[Top]

The CAAAuiCreateCstInAssy Use Case

CAAAuiCreateCstInAssy is a use case of the CAAAssemblyUI.edu framework that illustrates CATAssemblyInterfaces framework capabilities.

Before discussing the use case, some main concepts have to be introduced:

• A fix constraint is a geometrical relation created on one component only.

• Fixing a component means preventing this component from moving from its parent component during the update operation.
  Note that it means fixing its position according to the geometrical origin of the assembly.

• The constrained component must be child component of the active component.

[Top]

What Does CAAAuiCreateCstInAssy Do

Two components can be seen on the picture, here two mechanical parts:

1. Jack_Frame
2. Jack_Branch_3

These components are the child components of the root product Fix which is also the active component. The active component Fix is a selected component currently being edited and it is blue framed in the specification tree.

Constraints can be applied between the child components of the active component Fix.
Constraints appear in the specification tree at the same level as the child components and they are displayed in the geometry.

These concepts are the counterpart, on the programming side, of what the end users sees and manipulates on the screen. So we will start with the end user view in order to infer what the program manipulates inside.

[Top]

How to Launch CAAAuiCreateCstInAssy

To launch CAAAuiCreateCstInAssy, you will need to set up the build time environment, then compile CAAAuiCreateCstInAssy along with its prerequisites, set up the run time environment, and then execute the use case [2].

Launch the use case as follows:

• With Windows

  e:>CAAAuiCreateCstInAssy InputDirectory\Fix.CATProduct

• With UNIX

  $ CAAAuiCreateCstInAssy InputDirectory/Fix.CATProduct

where:

[Top]

Where to Find the CAAAuiCreateCstInAssy Code

The CAAAuiCreateCstInAssy use case is located in the CAAAuiCreateCstInAssy.m module of the CAAAssemblyUI.edu framework:

where InstallRootDirectory is the directory where the CAA CD-ROM is installed.

[Top]

Step-by-Step

There are three main steps in CAAAuiCreateCstInAssy:

1. Loading a Product Document in Session
2. Creating a Connector
3. Creating a Constraint

We will now comment each of those sections by looking the code.

[Top]

Loading a Product Document in Session

A CATProduct document is loaded in session. This is described in the Product Structure use cases [1].

[Top]

Creating a Connector

::GetProductConnector(pGeometry,
                      pInstanceComponent,
                      pActiveComponent,
                      0,
                      pConnector,
                      iCreation);

The GetProductConnector global function is used to create a connector on a component instance.

[Top]

Creating a Constraint

rc = ::CreateConstraint(catCstTypeReference,
                        ConnectorList,
                        NULL,
                        pActiveComponent,
                        pCst);

The CreateConstraint global function is used to create a constraint on/or between component instances.

[Top]

In Short

This use case has demonstrated the way to constraint the components of an assembly, create a connector and a constraint.

[Top]

References

History

Copyright © 2000, Dassault Systèmes. All rights reserved.