2 Replies Latest reply on Jun 29, 2012 3:14 PM by 1-56THY4

    2D Constraint Solver Issues

      If SolidWorks Corp. and SolidWorks users are truly interested in fixing long standing issues with SolidWorks I think reading and understanding what's in this blog post would be beneficial: 

       

      http://www.3dcadtips.com/cheetah-creo-2d-geometric-constraint-solvers/

       

       

      Jon Banquer

      San Diego, CA

      http://cadcamtechnologyleaders.blogspot.com/

        • Re: 2D Constraint Solver Issues

          It seems to me that this CAD company has got real control over their destiny because they have complete control over some of the most critical software components used in their product:

           

          http://www.bricsys.com/common/news.jsp?item=542

           

          "The intellectual properties rights of LGS 2D and 3D were acquired from LEDAS by Bricsys in October, 2011. The software development team of Bricsys Technologies Russia, a fully owned subsidiary of Bricsys NV and led by Dr. Dmitry Ushakov, continues the development of the state-of-the-art constraint solving technology currently embedded into dozen engineering applications including Bricscad V12."

           

          My guess is that LEDAS developed the constraint solvers used in Catia.

           

           

          Jon Banquer

          San Diego, CA

          http://cadcamtechnologyleaders.blogspot.com/

            • Re: 2D Constraint Solver Issues

              http://www.cloud-invent.com/Parametric-CAD/Bottleneck2.aspx

               

              History tree as the other bottleneck:

               

              "The drawback of the feature-based (in other words – history based) design technique, which is founded on regenerating a model from its history tree, is that, as more features are added, the geometry is dependent upon more and more features created earlier. This often leads to problems, if designer decides to do modifications in some features at the top of the feature hierarchy.

               

              In order to avoid these modification problems, users of a history-based application have to plan carefully the design, defining ahead of time which major elements would be dependent upon other elements. But planning a long hierarchical sequence of features (if the parts to be designed are complicated enough) might be not an easy task.

               

              On the other hand, non-efficient 2D Solver (that is not able to resolve really big sketches) leaves to designer no way around but to create a lot of small features. Very often designers have to divide parts into numerous “unnatural” features, because the “natural” features have such a complicated underlying sketches, that 2D Solver is not able to solve corresponding systems of equations. As a result this leads to the history tree of the part, which is much more extended. And the whole design process becomes much trickier.

               

              These observations show that when it comes the time to do some modifications in the existing feature-based models we are in front of numerous problems. But interactive modification of the model is the fundamental aspect in any design activity! Designer is constantly going forward and backwards, re-elaborating once and again some particular aspect of the model, or its general layout, or even coming back to a previous solution that had been temporarily abandoned. With feature-based CAD these modifications are tricky.

               

              The principal limitation of the parametric feature-based approach is the lack of simple instruments to modify interactively a model once it has been created."