Saturday, November 17, 2012

Do Parametric and Direct Modeling Mix?


During product design, teams are often forced to compromise when it comes to using CAD software. Most users are limited to one 3D modeling paradigm – either parametric or direct – for all jobs. Recently, however, vendors have begun to offer CAD tools that they say provide both paradigms.
Unfortunately, these tools typically require you to switch between two different modes and sometimes even two different model representations, never truly combining the strengths of both modeling paradigms in one product design or model.
If you’ve tried to work in one of these environments, you might have concluded that the two work in parallel, but don’t truly integrate with one another.
PTC Creo changes all that. Designers can choose the right modeling approach for the design, all in one environment, with a common data model. The PTC Creo Flexible Modeling Extension adds direct modeling or editing of parametric designs to the familiar PTC Creo Parametric environment.
PTC Creo Flexible Modeling Extension offers many unique advantages as you work in one seamless tool:
  • One common data model is maintained, tracking and synchronizing changes made using either a parametric or direct modeling approach. The system never requires you to duplicate design data or design changes.
  • Design intent can be protected and preserved in one model.
  • One common user interface means fast ramp up. You’ll never have to switch between modes only to find limited capabilities in one mode versus another.
  • Design changes made using a direct modeling approach can be incorporated by revising the parametric design intent.
Those advantages help throughout the product design process. Use the PTC Creo Flexible Modeling Extension when you want to:
  1. Explore more ideas during concept design.
  2. Drive late-stage design changes.
  3. Re-use legacy 3D design data.
  4. Collaborate on a multi-CAD design.
  5. Improve CAE & FEA workflow.
  6. Improve manufacturing workflow.
In part 1 of this article, I’ll look at the first three of these:
1.  Concept Design
During concept design, you want to convey a visual representation of product ideas or concepts, create as many design concepts as possible, and evaluate ideas to find the concept that best captures specified criteria and aesthetic requirements.  By combining modeling paradigms, you can build on existing designs or create new ones, with speed, flexibility, and ease of use.
See how PTC Creo supports the quick creation and ideation of geometry from existing parametric designs, so that you don’t have to worry about original design intent. But at the same time, it tracks and keeps all your changes in sync with the parametric model.
2.  Late-Stage Design Changes
Accommodating late-stage design changes supports design innovation, but those changes are often   radical and unexpected. And typically, they need to be rapidly implemented.
By enabling direct editing of parametric models, you can implement late changes quickly and avoid any design intent that limits those changes.  Again, because those changes are made using a direct editing approach, they are tracked and kept in synch with the parametric model.
3. Legacy CAD Data
Many companies keep 3D data authored on outdated software. Unfortunately, traditional CAD solutions do easily make changes to non-native CAD data, with 3D CAD data often treated as “dumb.” That makes legacy data  difficult to maintain, edit, and repurpose.
With direct modeling, you can use legacy data in new product revisions and even new product. You can repurpose and modify it easily, while combining it with other models created in a parametric or direct modeling approach.
Watch this space for the second part of this article, when I’ll explore multi-CAD design, CAE & FEA workflow, and manufacturing workflow.