Three-dimensional solid modeling is a rapidly emerging area of CAD, revolutionizing the way industry integrates computers into the design process. Commercial solid 3-D modeling packages, available since the early 1980s, have rapidly made inroads into a wide range of industries over the past few years.
Two-dimensional CAD has matured, in many ways, to the point where simply using a more powerful computer will not have much of an impact on how well a 2-D CAD program functions. Like traditional drafting methods, 2-D CAD programs attempt to represent objects in two dimensions; in fact, the packages were originally developed to be computer drafting tools, with the end product being a drawing on paper. In contrast, a 3-D solid computer model is more like a real object, not just a drawing of the object; 3-D CAD is considered a computer modeling tool.
This chapter introduces the possibilities for, and the limitations of, integrating 3-D CAD operations into the design process. While 3-D solid modeling software has enhanced such integration, it has not yet completely replaced more traditional 2-D documentation or physical prototypes.
The chapter outlines the most common approaches for generating 3-D solid computer models, in addition to how these models are viewed and modified on the computer. A particular focus is put on constraint-based modeling techniques and their relationship to documentation, analysis, and manufacturing technologies.
