In Part 1 I described my observations regarding how Solid Edge ST3 lines up with some of the typical issues related to traditional parametric history-based modeling. In this Part 2 I will share some of the other crazy observations I have:
Here is a statement coming from synchronoustechnology.net: “You no longer have to choose which modelling workflow to use up front, instead it is a simple case of switching between ordered (traditional) and synchronous whenever required.” And, by the way, if you “switch”, or move an ordered feature to Synchronous, there is no going back. It’s a one way trip. Siemens still provides no ability to rationalize the history-tree (ordered) from a direct model/feature (synchronous). Something that Autodesk is struggling to solve with their Change Manager. With SE ST3 it seems real simple to move ordered features to synchronous. Since it is a one-way trip, I wonder how long it will take before all your Solid Edge history-based (ordered) data is completely history-free (synchronous/unordered).
When reading about SE ST3 I started having flashbacks to the mid 90’s. This started sounding strangely familiar. At the time I was fairly close to the developers of TriSpectives at 3D/Eye, now known as IronCAD, (CAXA in China). Here is a good article with some of the IronCAD history. IronCAD has always been and is still a parametric history-based system at its core. Although it was only a few years ago that they exposed the history tree structure to the user. Due to the systems ability to automatically reorder the tree structure, it was infrequent that a user actually needed to manipulate the structure manually. IronCAD did several things different from traditional history-based modeling systems. I had included much more detail on IronCAD while writing this but as I was writing Deelip Menezes published an extensive review of IronCAD. So I will refer you to his review for more detail on the similarities of IronCAD and SE ST3. In summary there are many similarities, although IRONCAD has been providing this type of "mixed mode" capability for many years now.
It seems to me that the synchronous features in the ST3 tree simply represent a single B-Rep model organized somewhere in the tree. You might consider it what other parametric history-based systems refer to as the “base feature”, although with ST3 this B-Rep is ordered somewhere in the tree, and can contain UDF’s (user defined features). In ST3 these UDF’s are actually defined by a modeling operation. When you drag and drop a feature from ordered into synchronous, you are simply taking the geometrical results of an ordered feature and adding that geometry to this single B-Rep, and then removing the ordered feature definition. This single B-Rep becomes more complex, or detailed, with each addition. The resulting new faces in the B-Rep are tagged to keep them grouped as a UDF. Am I over simplifying this?
I am not saying that any of this is bad. On the contrary I like to see this kind of stuff pushing all of us in our thinking of CAD. But as you are considering this, just keep in mind what our ultimate objective really is; and that is - designing products (sometimes 3D models can help us do that).