Inventor Fusion Technology Preview 2 – Part 5

I finally got the Subscription Release of Inventor 2010 set up on my computer and started playing with it. Over the next few posts in this series I intend to share my experiences with the software while trying to get a sense of how this technology works. At the outset I would like to say that I do not have any inside information on the technology. Everything you read will be due to the conclusions I draw (rightly or wrongly) as I poke around. I urge you not to take this series as a review of Fusion. My aim here is more about finding out how this technology works and less about how good, bad or ugly it is.

As you may have noticed, Autodesk has made Inventor Fusion accessible to the general public who happen to reside in select countries. As I mentioned earlier, the download consists of Inventor Fusion (the standalone direct modeling application) and the Change Manager add-in to Inventor 2010. The thing is that the Change Manager add-in works only with the Subscription Release of Inventor 2010, which means that not everybody in the select countries can try it out. You need to be an Autodesk customer and that too have an active subscription of Inventor 2010. So I get the feeling that Autodesk wants to have a certain degree of control over who gets to experience the real “fusion” in Inventor Fusion. And since this experimental technology in its early stage, I guess it makes more sense to do so.

In this post, I will explain how data flows back and forth between Inventor 2010 and Inventor Fusion. For that lets step through a typical workflow. I start by creating a history based parametric feature model in Inventor 2010 and save it to an Inventor part file with an .ipt extension. I then open the IPT file in Inventor Fusion and thrash it around using Fusion’s direct modeling tools. When I proceed to save the file, Fusion does not overwrite the IPT file. Instead it prompts me to save it as a DWG file. Fusion then creates an AutoCAD 2010 DWG file, which Autodesk refers to as a Fusion-flavored DWG file because it write some special Fusion related information to it. To complete the roundtrip I then open this DWG file (not the IPT file)  in Inventor 2010. Upon doing so, the Change Manager add-in kicks in because it recognizes the DWG file as a Fusion DWG file. It then loads the original IPT file and compares the geometry with the changed geometry in the DWG file. It then cooks up a the list of changes and the recommends treatments for each change which when applied will modify the history based feature tree of the IPT file (refer Part 3) to make it seem as if the direct modeling changes were carried out in Inventor 2010 itself.

Among other things, Fusion stores the associated IPT file path in the DWG file. That’s how the Change Manager knows where to look for the original IPT file. If it does not find the IPT file at the specified path, Inventor 2010 proceeds to open the DWG file like it normally does without kicking in the Change Manager.

The most important part of this whole Fusion technology is the part where the Change Manager cooks up the list of changes and recommends the best treatments that ought to be applied for each change. Its like finding your way back from some place without knowing the path you took to get there. However, if you kept track of the path you took, then maybe tracking back may not be that difficult a task. So I wanted to know whether Fusion was secretly recording the direct modeling operations in some place which could then be used to guide the Change Manager later. I could think of two places where such data could be recorded – the IPT file and the DWG file. Or maybe Fusion could store this information in a temporary location on the computer or maybe not anywhere on the disk but in memory.

In the next part we will determine whether the Change Manager actually modifies a history based parametric feature tree by comparing a dumb solid in a DWG file with the original parametric model in a IPT file. Or does it use some sleazy method of keeping track of the direct modeling operations carried out by the user in Fusion and then use this data to cook up the changes and treatments. I can assure you that the results of this investigation will be very interesting. Do stay tuned. I have only got started.