Mod the Machine

Happy Holidays

I wish the best for you and your family for the upcoming new year.

For a little fun I wrote a Fusion script in Python that has two options.  For the first option it creates an extrusion of the words “Happy Holidays” and then creates a box that completely covers the “Happy Holidays” bodies where the bottom of the box is defined by a spline. The box entirely consumes the “Happy Holidays” so nothing is visible in the model at this point.  The second option modifies the spline points and randomly moves them upwards so the “Happy Holidays” slowly appears.  After each modification of the spline the program saves the current view as a png file and then I manually used GIMP to create the animated gif you see above.  Here’s the Python script in case you’re interested in how it works.

-Brian

Placing a Part in Inventor with User Interaction

The various add methods of the ComponentOccurrences objects let you place new parts or assemblies into an assembly, but in all cases you have to specify the position as part of the placement. There are times when you don’t know where it should be positioned and want to give the user the ability to position it. This can be done using a little known capability of the API.

The Place Component command has a special API behavior.  When the command is invoked, it typically displays the dialog to allow you to choose which part or assembly to place and then puts you in a mode where that part or assembly is attached to the cursor and each click creates a new occurrence.  The special behavior of the command is that it can bypass the dialog and go directly to the placement. It’s possible through the API to post the filename to a queue and when the command is executed it checks to see if there is a filename in the queue and if there is it uses it and skips the dialog.

The VBA sample below demonstrates this. It uses the PostPrivateEvent of the CommandManager object to post the filename to the private event queue. It then executes the Place Component command.  Calling Execute on a control definition is exactly the same as executing the command in the user interface. In fact if you comment out the last line in the program below and run it and then run the Place Component command in the user interface it will still skip the dialog step of the command. Once the filename is read from the queue, the queue is cleared so the next time the Place Component command is run it will run in the normal way and display the file dialog.

Public Sub PlacePartInteractive() 
    ' Define the filename to place.
    Dim filename As String
    filename = "C:\Temp\PartTest_2016.ipt" 

    ' Post the filename to the private event queue.
    Dim cmdMgr As CommandManager
    Set cmdMgr = ThisApplication.CommandManager
    Call cmdMgr.PostPrivateEvent(kFileNameEvent, filename)

    ' Execute the "Place Component" command.
    cmdMgr.ControlDefinitions.Item("AssemblyPlaceComponentCmd").Execute
End Sub

There is a downside to using this technique. With the typical Add methods, the occurrence is created and then passed back to your program where you now have control and can continue whatever processing you need to do. By executing a standard command you've essentially turned control of Inventor back to the user. If you're finished with whatever you need to do then this works great because you're done and don't need to get back control. Otherwise it gets more complicated because you'll also need to watch events to catch when new occurrences are placed and do whatever processing might be needed. I'll save that discussion for another time.

-Brian