Autocad 2012 Tutorial

AutoCAD 2012 Tutorial
®

Second Level: 3D Modeling

Randy H. Shih
Oregon Institute of Technology

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SDC

www.SDCpublications.com Schroff Development Corporation

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AutoCAD® 2012 Tutorial: 3D Modeling

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Chapter 3

3D Wireframe Modeling

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Using the Setup Wizard Create Wireframe Models Apply the Box Method in Creating Models Construct with the Copy Command Understand the Available 3D Coordinates Input Options  Using the View Toolbar  Setup and Using the TRIM options

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AutoCAD® 2012 Tutorial: 3D Modeling

Introduction
The first true 3D computer model created on CAD systems in the late 1970s was the 3D wireframe model. Computer generated 3D wireframe models contain information about the locations of all the corners and edges in space coordinates. The 3D wireframe models can be viewed from any direction as needed and are in general reasonably good representations of 3D design. But because surface definition is not part of a wireframe model, all wireframe images have the inherent problem of ambiguity. For example, in the figure displayed below, which corner is in front, corner A or corner B? The ambiguity problem becomes much more serious with complex designs that have many edges and corners.

Wireframe Ambiguity: Which corner is in front, A or B? The main advantage of using a 3D wireframe modeler to create 3D models is its simplicity. The computer hardware requirements for wireframe modelers are typically much lower than the requirements for surface and solid modelers. A 3D wireframe model, also known as a stick-figure model or a skeleton model, contains only information about the locations of all the corners and edges of the design in space coordinates. You should also realize that, in some cases, it could be quite difficult to locate some of the corner locations while creating a 3D wireframe model. Note that 3D wireframe modelers are usually