The LEDAS View On Synchronous Technology

Siemens PLM and LEDAS are business rivals in the 2D and 3D constraints technology space. Siemens PLM has D-Cubed 2D and 3D DCM and LEDAS has LGS 2D and LGS 3D. As component vendors they keep running into each other all the time, trying to woo the same customers. Till recently, LEDAS was purely a component vendor and didn’t have end user products of their own like Siemens PLM. That has changed. For some time LEDAS has been using its core constraint domain knowledge to create a direct modeling technology. They have been calling it Variational Direct Modeling. Over a year I wrote an article on this blog titled “Variational Direct Modeling” on the subject. They have wrapped their technology into two products implemented as plug-ins for SketchUp and Rhino (see On the other hand, Siemens has been using its constraints know how to further Synchronous Technology. So this is a little bit of history that will help you understand the rest of this post.

isicad is publication that  covers the Russian CAD/PLM space. Although Siemens PLM advertises on isicad, it recently refused to give the editors a review license of Solid Edge ST3. And I can understand why. Because isicad is run by LEDAS.

Today one of the many geniuses at LEDAS, Dr. Dmitry Ushakov wrote a very interesting paper on isicad titled “Synchronous Technology: The Third Attempt“. Interesting because, since Siemens PLM didn’t give him access to the software, he made use of my 11 part “Synchronous Technology in Solid Edge ST3” series to draw his conclusions. If you are interested in knowing more about the innards of direct modeling technology, I suggest you read it.

However, I must warn you. It can get a bit technical. In fact, knowing Dmitry I think he has actually dumbed it down. You see, the man is a mathematical fountain. He can sit and talk simultaneous equations and high level derivatives to you all night long and continue the next morning. I spent a great deal of time with him during my recent visit to Russia. Even vodka didn’t stop the man. If not the whole paper, I suggest that you at least read the conclusion. Here is a part of it:

“Synchronous technology is our future but why it has to come in the same package with an obsolete apparatus of history-based parametric modeling? These two approaches can hardly be combined due to significant conceptual differences, and as result a composed solution is controversial and unnatural for the users.”

You can read the entire paper here.

  • d3print

    As I earlier said, ST3 will be confusing (too much) users. Nice to see that there are more and more people that noticed same thing.

    • That is precisely why I took the time to explain in excruciating detail the basics of the new history tree. There is a lot more to it. The good thing is that users have the option to adopt it at their own convenience. Or not use it at all.

    • That is precisely why I took the time to explain in excruciating detail the basics of the new history tree. There is a lot more to it. The good thing is that users have the option to adopt it at their own convenience. Or not use it at all.

  • Dan Staples

    Just to be clear, you can use Solid Edge in a totally Synchronous way and never know/learn anything about the ordered feature modeling concept (the ordered node does not appear when it is empty). Likewise, you can be an ordered type of user and never consider the Synchronous side if that is not your thing. The only time they appear together is when you (likely as an experienced user) choose to mix and match. This “progressive disclosure” approach allows you to learn at your own pace and involve only the technologies of interest to you.

  • Roger

    There has been a fair bit of talk (mostly conjecture) about the complicated nature of the “dual” tree in ST3. I’ve only been using it for a bit over a week now and really haven’t found it an issue – don’t know what the fuss is about.

    • I agree Roger. Once you understand the fact that the Synchronous section is simply the first node in an Ordered tree, what’s to figure out? I think certain folks are just trying to make a mountain out of a mole hill.

      • chad

        I don’t have solidedge but you guys might be able to give a little more clarity. I do a lot of in-context modeling using solidworks and I’m curious about the equivilant in solidedge. To me it would seem that moving something from the history side to the synchronous side might break the referential integrity at the assembly level. I guess the confusion for me is that the feature in the history side becomes a new feature on the synchronous side once it is moved. Is this assumption correct?

        • When you transition ordered features to Synchronous, you actually don’t recreate any geometry. The body and all it’s faces are exactly the same. What changes at that point is how you interact with it. That said, any reference to those faces is maintained because they did not change.

          Now more specifically addressing your “in-context” question, Solid Edge uses something called “Inter-part” to facilitate “in-context” modeling. In that case, those Inter-part relations are not to faces, but rather to sketch entities that drive faces. Since the sketch is not used anymore those relationships are discarded, however it is rather easy to replace them with the new Inter-part Relationship wizard in the Synchronous environment. The reason it is not done automatically is because there may be many possible results of a surface edge to sketch relationship and to try and have that guessed automatically may be incorrect at times, so better to err on the side of quality and let the user make the decision.

      • d3print

        Is that marketing problem or end-user problem that it causes so many questions? I`m the end-user of SolidEdge, still using ST1, but not for my own will. Hope that the real world is not so complicated
        with ST3 than it look like now.
        Have to say again, keep it simple.

  • Dave Ault

    I am a little puzzled by ST3 being confusing as a mix of history and ST. It is like Dan says and you can choose how you want to work. If you are still on ST1 I highly recommend that you go to ST3 as it is a far more powerfull and polished product. Personally speaking I will no doubt get around to fooling with the combination of history and ST just for curiosities sake but for earning a living I am strictly using ST and never open the history side up.