Thoughts on “Design Development Environments” by Daniel Schodek

CAD, in the hands of an unskilled operator can be used to make some very interesting forms, but as the article states “It is often more difficult to understand what has been created than to generate the surface itself.” Meaning, the model is supposed to represent a real-actual object that is going to be built. What does your CAD shape represent? Can it be built using materials at hand?

One way of building involves developable and nondevelopable surfaces. “A nondevelopable surface…requires cutting and/or stretching if it is to be flattened out into a planar sheet.” A developable one being the opposite, and being easily turned into a flat 2-dimensional sheet. Of course this terminology is indicative of the pervasive building paradigm of the last hundred or so years since the mass adoption of mass produced sheeting materials such as plywood and sheet metal.

Sheet metal unlike plywood can be stretched into nondevelopable surfaces. This entails Gaussian curvature. Positive Gaussian curvature (synclastic) means concave or convex shapes, and negative Gaussian curvature (anticlastic) means the curvature switches from concave or convex like a saddle. These terms seem to be from the math discipline, and not really used by designers, but used extensively by the smart, SMART, folks who program our CAD software.

No matter how smart they are, programmers are not designers. And it takes a special kind of mind to be a good designer when using CAD. Many of the modeling techniques talked about (especially Feature Based Model Building) require an extensive foresight. “…building of the model and the definition of key dimensions must frequently anticipate design changes that inevitably occur during the development process.” The model must be set up correctly in the beginning as future limitations insofar as altering/modifying the model will be present. Of course not all things can be predicted by the mistake prone human brain, and hence “In practice it is not uncommon to rebuild a model completely as the design progresses, because detailed technical questions necessitate changes that were not initially anticipated.”

There is another job that good Designers do. I’m talking about designers who bridge the gap between design and engineering. They design with process in mind. They draw CAD models while always having in mind the real-world procedures and tools which they will use to actually build the thing. This is the kind of thing the software is beginning to get to, and it was talked about in the section called Application-Oriented Modeling Techniques. This is the area of the greatest deficit in CAD, and improvements here will embody the Future of CAD. I imagine a day when the CAD Designer steps into a virtual first person environment and dictates a stock material, and its dimensions. This then opens a toolbox of actions which he/she can perform on the material. These actions will be direct allegories to real-world processes. If the designer tries to do actions which would lead to manufacturing problems, the program will either model these problems (Like cracks in the material) or it will display an error warning (Like “the draft angle of your mold makes the part unable to release from the mold”). Of course, when the software does all that, what is to keep it from doing the actual designing as well? With the software designing the self-driving cars, will there be any use for us human beings? At least we’ll make great pets.

Note: All quotes came from the chapter itself.