What is difference between polygonal modeling and CAD modeling?
I have been hearing about two different types of 3D modeling. While one category is the CATIA, AutoCAD, and Solidworks, the other category is Blender and maya. A bit into research I understand that one is CAD modeling and the other Polygonal modeling. So, what is the difference between the two? How could be the two varieties useful to a mechanical engineer
2 Answer
The lines get a bit blurry, but here is how I view them:
Catia, SOLIDWORKS, and similar programs are mechanical design packages. You use them to design, analyze, document objects which are then often produced as physical items through various production methods.
Blender, Zbrush, Maya are often used in the graphics industry, and they excel at creating more organic shapes compared to the somewhat mechanical nature of traditional CAD programs. The objects created in these sculpting programs are often quite lovely, but they are also not easy to use for production. They are well suited for 3D printing, but not injection molding, or CNC work. These programs can have a huge benefit as concept modelers where several different concepts can be "quickly" explored in the time it would take to fully realize a single model in a traditional CAD program.
I've tried a few times to learn some of the sculpting programs, but they are quite different from the CAD world I am used to.
If you can use both types of programs, there would only be positive outcomes for your future.
I think we're going to see more and more subdivision modeling capability in the top tier CAD packages as time goes on. It does give us a nice way of analyzing and manipulating coarse (<10k faces) wavefront (.obj) polygonal models. Not to mention, an additional aid in terms of bridging the surfacing skills gap, which tends to limit design options.
Most design is limited to traditional manufacturing methods and that drives design feasibility. Additive Manufacturing (AM) is changing that a lot and I'll admit that for myself, as a mechanical design engineer, most of my surface design experience has been in building 'functional' surfaces, governed by tolerance and continuity concerns. That is... until AM became the feasible alternative for functional prototyping and small lots.
Long story short... I believe AM will continue to drive the necessity to create more organic forms that wouldn't be feasible for manufacture any other way. The skills gap will become more apparent as time goes on.
NX's Realize Shape is a great module for bridging that gap and I believe Catia has something similar... though the name escapes me at the moment.
