Wednesday, May 4, 2011

How to extract 2D AutoCAD geometry from an Autodesk Inventor DWG Drawing File.

An article by Paul Munford (The CAD Setter Out) For CAD Clues Blog. 

If you regularly exchange drawing files with a Client, colleague or Contractor who is using Autodesk Inventor, then you may be interested in this simple trick for Extracting 2D geometry from an Inventor DWG file.

To try this out, you will need:
· An Autodesk Inventor DWG file
· AutoCAD!

TIP: You will need an Inventor DWG file – not an Inventor IDW file. This is Inventor’s own drawing file format and cannot be opened by AutoCAD.

Our DWG File open in Inventor.

OK, how do we go about it?
The process is simple. First we will open the Inventor DWG up in AutoCAD, and then we will hunt out the Information we need.


The Autodesk Inventor Sheet browser – showing the Views we wish to use in AutoCAD.

Inventor DWG Weirdness.
Inventor DWG files open up in AutoCAD just fine. You will see that the Paper Space layout looks just like Inventor’s Sheet layout.


Our DWG File open in AutoCAD.

However, you may notice a little Weirdness when you look in Model space – there is nothing there!
Although Inventor can create perfectly readable AutoCAD DWG files, the Inventor information is kept in its own magical world – somewhere between Paper Space and Model Space.
So how do we get at the Inventor Geometry?
The trick is simple – when you know it! The Inventor Views exist in the DWG file as AutoCAD blocks. So to get information from the Inventor drawing views, all you have to do is use AutoCAD’s ‘INSERT’ command.

The Autodesk Inventor Views are available in AutoCAD as ‘Blocks’.

Inserting an Inventor View as a Block in Model space.
While in Model Space in AutoCAD, type ‘INSERT’ at the command line and check out the list of available blocks in the drop down. You will notice that each block corresponds to an Inventor view.
Simply insert your desired view into model space as a block, making sure that the block is inserted at 1:1 scale. If you need to edit the geometry you could explode the block now.
TIP: You can also insert the Block information contained in the DWG file through the AutoCAD Design Centre. You will even get a nice preview!

The AutoCAD Design Centre is a great tool for raiding Inventor DWG’s for View Blocks.

Maintaining the Link
If you don’t explode the AutoCAD block, then Autodesk Inventor will continue to control the block definition. This means that you could X-Ref the 2D AutoCAD block into another AutoCAD drawing and maintain the link all the way back to the Inventor model.
Any changes in the Inventor 3D model, would update the Inventor DWG drawing file. When the Inventor DWG Drawing file is subsequently opened in AutoCAD the changes will register. When the X-ref’d drawing is opened the user will be prompted to update the X-ref’d Inventor DWG file – thus completing the chain.
What could you do with this technique?
Does this sound easy to you?
Have you already tried this method out?
How could you see this technique being used in your company?

Please feel free to leave a comment.
About the CAD Setter Out.

Paul Munford is a Joinery draughtsman (a ‘Setter Out’) for Beck Interiors, a UK based international Interior Fit out contactor which specialises in Museum Interiors.
Paul uses Autocad and Autodesk Inventor to create manufacturing ‘Workshop’ drawings day in – day out.
In his spare time Paul writes the ‘CAD Setter Out’ Blog and tries to explain to people why he goes to all the effort!