Cadalyst - July 2008 - (Page 37)

mcadmodeling Figure 2. This image is a control arm from a 1972 Super Beetle that I modeled at home. Having 3D modeling software at home can be a very handy thing. You learn the software and create some wonderful models to boot! packages — so much so that some of the high-end vendors are engineering functionality pioneered in the mid-range packages into their own products. What a turnaround! Of course, the high-end companies haven’t — for the most part — been shut out of the fight. They saw that they couldn’t keep ahead of the mid-range companies forever, so they came up with a new strategy. The trend in today’s high-end software is product lifecycle management (PLM). The thinking goes something like this: You should let them give you a hand in every part of your product’s development, including manufacturing and even purchasing and distribution. PLM starts with the proverbial napkin sketch (now intended to be electronic), goes through virtual model creation, tells purchasing how much of what materials to order, provides instructions for tooling, takes care of inventory, and helps with any changes that need to be made anywhere down the road. In short, PLM seeks to facilitate everything about your product from initial concept to product retirement. It’s a lofty goal. And I tend to think even the little guy will end up there in a few years. Figure 3. In a history-based modeler you perform commands in a particular order, which constitutes a formula for creating your model. Things that appear further down the history tree frequently are dependent upon what came before them, which can make editing a challenge if you’re not careful. Figure 4. In direct modeling, you can modify geometry no matter where it came from or whatever order it was built. You can even do some very parametric-like things. you achieve any configuration you need. In some programs you can even apply dimensions to that geometry that will lock it into certain behaviors (figure 4). Direct Modeling During the past year or so, there’s been a lot of noise about so-called direct modeling. For those not in the know, that’s mostly nonparametric modeling directly on the model geometry. This area is an offshoot of the whole history versus nonhistory war. Modeling history keeps track of what you’ve done and the order in which you did it (figure 3). Parametric modeling might be handy for reproducing a model, but it can also complicate your model to the point where you can’t make changes because it has so many interactions and interdependencies. Direct modeling allows you to work on models without regard to their history. Compatibility has always been a wait-a-minute topic for 3D MCAD. You get a model that you need to either incorporate into your design or design around. What do you do? What can you do with it? Most often, you have what amounts to a collection of surfaces that enclose a volume — the technical definition of a solid body. In direct modeling, you can push and pull the geometry all around until July 2008 cadalyst www.cadalyst.com Reaching the Masses I used to say that when your product is in Wal-Mart, then you’ve really reached the masses. Now, with products available on the Internet for free, there’s no longer any excuse for people who need them not to have them. I can’t help being optimistic about the MCAD industry. I think it is important for the economy, and I think it will only continue to be more so. I see great progress from all the different ranges — low, mid, and high. New capability is now available that is changing how we do things — if we let it. Mike Hudspeth, IDSA, is an industrial designer, artist, and author based in St. Louis, Missouri. Read More at Cadalyst.com MCAD Modeling archives www.cadalyst.com/MCADModeling 37 http://Cadalyst.com http://www.cadalyst.com/MCADModeling http://www.cadalyst.com

Table of Contents Feed for the Digital Edition of Cadalyst - July 2008

Cadalyst - July 2008 Editor’s Window CAD Central FIRST Robotic Beasts Draw Students to Engineering Power! Speed! Action! — Mighty Mobile Workstations are Packed and Ready for Adventure! Vico Virtual Construction Suite 2008 AMD ATI FireGL V8600 and FireGL V8650 — 1-GB and 2-GB Graphics Cards Gaining Independence and Influence The Current State of MCAD Rewriting the Rules of PDM BIM Goes Residential CAD Cartoon Issue Indexes Pleasures of Customization

Cadalyst - July 2008

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