AutoCAD 2005 for Dummies

? Closing up with rectangles and polygons

? Rounding the curves with circles, arcs, splines, and clouds

? Dabbling in ellipses and donuts

? Making your points

As you probably remember from your crayon and coloring book days, drawing stuff is fun. CAD imposes a little more discipline, but drawing AutoCAD objects is still fun. In computer-aided drafting, you usually start by drawing geometry — shapes such as lines, circles, rectangles, and so on that represent the real-world object that you’re documenting. This chapter shows you how to draw geometry.

After you’ve created some geometry, you’ll probably need to add some dimensions, text, and hatching, but those elements come later (in Part III of this book). Your first task is to get the geometry right; then you can worry about labeling things.

  Drawing geometry properly in AutoCAD depends on paying attention to object properties and the precision of the points that you specify to create the objects. I cover these matters in Chapter 4, so if you eagerly jumped to this chapter to get right to the fun stuff, take a moment to review that chapter first.

Introducing the AutoCAD Drawing Commands

For descriptive purposes, this chapter divides the drawing commands into three groups:

? Straight lines and objects composed of straight lines

? Curves

? Points

AutoCAD-based application-specific programs such as Architectural Desktop add extra drawing tools to the mix — for example, commands for drawing walls and doors. See the documentation that comes with the application-specific program for information on such tools. Table 5-1 offers an overview of most of the drawing commands in AutoCAD, without the 3D-related commands. It describes the commands’ major options and shows you how to access them from the command line, the Draw menu, and the Draw toolbar. (Don’t worry if not all the terms in the table are familiar to you; they become clear as you read through the chapter and use the commands.)

Table 5-1 AutoCAD Drawing Commands

Button	Command	Major Options	Toolbar Button	Draw Menu
	Line	Start, end points	Line	Line
	RAY	Start point, point through which ray passes	None	Ray
	XLine	Two points on line	Construction line	Construction line
	PLine	Vertices	Polyline	Polyline
	POLygon	Number of sides	Polygon	Polygon inscribed/circumscribed
	RECtang	Two corners	Rectangle	Rectangle
	Arc	Various methods of definition	Arc	Arc; submenu for definition methods
	Circle	Three points, two points, tangent	Circle	Circle; submenu for definition methods