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From Drawings … to Models

For millennia, people have documented the design and construction of three-dimensional objects by drawing two-dimensional views of them. Most people have continued to use these “classical” methods with CAD drafting because the methods are well understood and work reasonably well. After all, if 2D drawing was good enough for guys like Leonardo da Vinci and Andrea Palladio, it should be good enough for us, right?

Nonetheless, for the last decade or so, there's been a trend toward creating 3D CAD models and letting the software generate the 2D views more-or-less automatically. This approach seems more logical, especially if the project documentation requires numerous, complex views of the same object. 3D modeling also is an absolute necessity when you want to create rendered views for presentation purposes.

While the AutoCAD's 3D construction and visualization tools have improved dramatically over the years (trust me — you should have seen what they were like as recently as AutoCAD 2006!), it's still a complex process that requires sophistication on the part of the AutoCAD user. Although 3D modeling requires only one more dimension than 2D drafting, developing 3D CAD models is considerably more complicated. Users must master new techniques and contend with the 2D limitations of most display screens and input devices.

In the previous chapter, I showed you how to move around models that others have made, and explained the principles of 3D coordinate systems that you need to understand to work in AutoCAD's 3D environment. This chapter introduces you to the concepts, tools, and techniques of AutoCAD 3D modeling itself; here you can get your feet wet creating your own 3D objects.