You'll start by creating a new file called Bath. Then you'll set up the unit style.

Use these steps to create the file:

The next thing you want to tell AutoCAD is the unit style you intend to use. So far, you've been using the default, which is a decimal inch. In this unit style, whole units represent inches and decimal units are decimal inches. If you want to be able to enter distances in feet, you must change the unit style to a style that accepts feet as input. You'll do this through the Drawing Units dialog box shown in Figure 3.1.

If you're a civil engineer, you should know that the Engineering unit style lets you enter feet and decimal feet for distances. For example, the equivalent of 12′-6″ is 12.5′. If you use the Engineering unit style, you'll ensure that your drawings conform to the scale of drawings created by your architectural colleagues.

Figure 3.1. The Drawing Units dialog box

Follow these steps to set a unit style:

You can also control the Drawing Units settings by using several system variables. To set the unit style, you can type ×lunits

If you use the Imperial system of measurement, you selected Architectural measurement units for this tutorial, but your work may require a different unit style. You saw the unit styles available in the Drawing Units dialog box. Table 3.1 shows examples of how the distance 15.5 is entered in each of these styles.

In the previous exercise, you needed to change only two settings. Let's look at the other Drawing Units settings in more detail. As you read, you may want to refer to Figure 3.1.

Most of the time, you'll be concerned only with the units and angles settings of the Drawing Units dialog box. But as you saw in the preceding exercise, you can control many other settings related to the input and display of units.

Taking Measurements

To measure the distance between two points, click Distance from the Home tab's Utilities panel, or type Di

The Precision drop-down list in the Length group lets you specify the smallest unit value that you want AutoCAD to display in the status bar and in the prompts. If you choose a measurement system that uses fractions, the Precision list includes fractional units. You can also control this setting with the Luprec system variable.

The Angle group lets you set the style for displaying angles. You have a choice of five angle styles: Decimal Degrees, Degrees/Minutes/Seconds, Grads, Radians, and Surveyor's Units. In the Angle group's Precision drop-down list, you can specify the degree of accuracy you want AutoCAD to display for angles. You can also control these settings with the Aunits and Auprec system variables.

You can find out more about system variables in the Help window. Select the Contents tab of the Help window, and then expand the Command Reference listing. Locate and expand the System Variable listing under Command Reference.

You can tell AutoCAD which direction is positive, either clockwise or counterclockwise. The default, which is counterclockwise, is used in this book. You can also control these settings with the Angbase and Angdir system variables. The Direction Control dialog box lets you set the direction of the 0 base angle. The default base angle (and the one used throughout this book) is a direction from left to right. However, at times you may want to designate another direction as the 0 base angle.

The Insertion Scale setting in the Drawing Units dialog box lets you control how blocks from the Tool palettes or DesignCenter are scaled as they're imported into your current drawing. A block is a collection of drawing objects that form a single object. Blocks are frequently used to create standard symbols. You'll learn more about blocks in Chapter 4. The Insertion Scale setting lets you compensate for drawings of different scales by offering an automatic scale translation when importing blocks from an external file. The Insunits system variable also controls the Insertion Scale setting. You'll learn more about this setting in Chapter 29.

If you're new to AutoCAD, don't worry about the Insertion Scale setting right now. Make a mental note of it. It may come in handy in your work in the future.

One of the big advantages of using AutoCAD is that you can draw at full scale; you aren't limited to the edges of a piece of paper the way you are in manual drawing. But you may find it difficult to start drawing without knowing the drawing boundaries. You can set up some arbitrary boundaries using the Limits feature. You got a taste of the Limits feature in Chapter 1. You'll use it again here to set up a work area for your next drawing.

You'll be drawing a bathroom that is roughly 8 feet by 5 feet (230 cm by 150 cm for metric users). You'll want to give yourself some extra room around the bathroom, so your drawing limits should be a bit larger than that actual bathroom size. You'll use an area of 11′ by 8′-6″ for the limits of your drawing. Metric users will use an area 297 cm by 210 cm. These sizes will accommodate your bathroom with some room to spare.

Now that you know the area you need, you can use the Limits command to set up the area:

In step 5, the coordinate readout shows you that your drawing area is larger than before, but no visual clues tell you where you are or what distances you're dealing with. To help you get your bearings, you can turn on Grid mode, which you'll learn about toward the end of this chapter. Grid mode displays an array of dots that help you visualize distances and the limits of your drawing.

As an alternative to setting up the drawing limits, you can draw a rectangle that outlines the same area used to define the drawing limits. For example, in the previous exercise, you could use the Rectangle tool to draw a rectangle that has its lower-left corner at coordinate 0,0 and its upper-right corner at 132,102 (297,210 for metric users). You can set up the rectangle to be visible without printing using the Layer feature. You'll learn more about layers in Chapter 5.

When you draft manually, you work on the final drawing directly with pen and ink or pencil. With a CAD program, you're a few steps removed from the finished product. Because of this, you need a deeper understanding of your drawing scale and how it's derived. In particular, you need to understand scale factors. For example, one of the more common uses of scale factors is translating the size of a graphic symbol, such as a section symbol in an architectural drawing, to the final plotted text size. When you draw manually, you draw your symbol at the size you want. In a CAD drawing, you need to translate the desired final symbol size to the drawing scale.

When you start adding graphic symbols to your drawing (see Chapter 4), you have to specify a symbol height. The scale factor helps you determine the appropriate symbol height for a particular drawing scale. For example, you may want your symbol to appear ½″ high in your final plot. But if you draw your symbol to ½″ in your drawing, it appears as a dot when plotted. The symbol has to be scaled up to a size that, when scaled back down at plot time, appears ½″ high. For a ¼″ scale drawing, you multiply the ½″ text height by a scale factor of 48 to get 24″. Your symbol should be 24″ high in the CAD drawing in order to appear ½″ high in the final plot. Where did the number 48 come from?

The scale factor for fractional inch scales is derived by multiplying the denominator of the scale by 12 and then dividing by the numerator. For example, the scale factor for ¼″ = 1′-0″ is (4 × 12) / 1, or 48/1. For 3/16;″ = 1′-0″ scale, the operation is (16 × 12) / 3, or 64. For whole-foot scales such as 1″ = 10′, multiply the feet side of the equation by 12. Metric scales require simple decimal conversions.

You can also use scale factors to determine your drawing limits. For example, if you have a sheet size of 11″ × 17″ and you want to know the equivalent full-scale size for a ¼″-scale drawing, you multiply the sheet measurements by 48. In this way, 11″ becomes 528″ (48″ × 11″), and 17″ becomes 816″ (48″ × 17″). Your work area must be 528″ × 816″ if you intend to have a final output of 11″ × 17″ at ¼″ = 1′. You can divide these inch measurements by 12″ to get 44′ × 68′.

Table 3.2 shows scale factors as they relate to standard drawing scales. These scale factors are the values by which you multiply the desired final printout size to get the equivalent full-scale size. If you're using the metric system, you can use the drawing scale directly as the scale factor. For example, a drawing scale of 1:10 has a scale factor of 10, a drawing scale of 1:50 has a scale factor of 50, and so on. Metric users need to take special care regarding the base unit. Centimeters are used as a base unit in the examples in this book, which means that if you enter a distance as 1, you can assume the distance to be 1 cm.

If you're working on a drawing from an older version of AutoCAD, you'll use scale factors to specify text height and dimension settings, so understanding them now will pay off later. Plotting to a particular scale is also easier with an understanding of scale factors.

In this section, you'll draw the first item in the bathroom: the toilet. It's composed of a rectangle representing the tank and a truncated ellipse representing the seat. To construct the toilet, you'll use Polar Tracking, which is one of the more versatile drafting tools. Polar Tracking helps you align your cursor to exact horizontal and vertical angles, much like a T-square and triangle.

In this exercise, you'll use Polar Tracking to draw a rectangular box:

Figure 3.2. A plan view of the toilet tank

As you can see from the exercise, you can use Polar Tracking to restrain your cursor to horizontal and vertical positions, just like a T-square and triangle. Later, you'll learn how you can set up Polar Tracking to set the angle to any value you want in a way similar to an adjustable triangle.

In some situations, you may find that you don't want Polar Tracking on. You can turn it off by clicking the Polar tool in the status bar. You can also press the F10 function key to turn Polar Tracking on or off.

Although this exercise tells you to use the Line tool to draw the tank, you can also use the Rectangle tool. The Rectangle tool creates what is known as a polyline, which is a set of line or arc segments that act like a single object. You'll learn more about polylines in Chapter 19.

By using the Snap modes in conjunction with the coordinate readout and Polar Tracking, you can locate coordinates and measure distances as you draw lines. This is similar to the way you draw when using a scale. The smallest distance registered by the coordinate readout and Polar Tracking readout depends on the area you've displayed on your screen. For example, if you're displaying an area the size of a football field, the smallest distance you can indicate with your cursor may be 6″ or 15 cm. On the other hand, if your view is enlarged to show an area of only one square inch or centimeter, you can indicate distances as small as 1/1,000; of an inch or centimeter by using your cursor.

You've seen how Polar Tracking lets you draw exact vertical and horizontal lines. You can also set Polar Tracking to draw lines at other angles, such as 30° or 45°. To change the angle Polar Tracking uses, you use the Polar Tracking tab in the Drafting Settings dialog box (see Figure 3.3).

Figure 3.3. The Polar Tracking tab in the Drafting Settings dialog box

Right-click the Polar tool in the status bar, and then choose Settings from the shortcut menu to open the Drafting Settings dialog box. As an alternative, you can type DS

To change the Polar Tracking angle, enter an angle in the Increment Angle text box or select a predefined angle from the drop-down list. You can do this while drawing a series of line segments, for example, so that you can set angles on the fly.

Numerous other settings are available in the Polar Tracking tab. Here is a listing of their functions for your reference:

To define the toilet seat, you'll use an ellipse. Follow these steps:

Figure 3.4. The ellipse added to the tank

During the drawing process, you'll often want to enlarge areas of a drawing to edit its objects. In Chapter 1, you saw how to use the Zoom capability for this purpose. Follow these steps to enlarge the view of the toilet:

If you have a mouse with a scroll wheel, you can avoid using the Zoom command altogether. Just place the cursor on the toilet and turn the wheel to zoom into the image.

Now let's see how editing commands are used to construct an object. To define the back edge of the seat, let's put a copy of the line defining the front of the toilet tank 3″ (7 cm for metric users) toward the center of the ellipse:

Figure 3.5. The line copied down

Notice that the Copy command acts exactly like the Move command you used in Chapter 2 except that Copy doesn't alter the position of the objects you select and that you must press

In this section, you'll see how planning ahead will make your use of AutoCAD more efficient. When drawing a complex object, you'll often have to do some layout before you do the actual drawing. This is similar to drawing an accurate pencil sketch using construction lines that you later trace over to produce a finished drawing. The advantage of doing this in AutoCAD is that your drawing doesn't lose any accuracy between the sketch and the final product. Also, AutoCAD enables you to use the geometry of your sketch to aid in drawing. While you're planning your drawing, think about what you want to draw, and then decide which drawing elements will help you create that object.

You'll use the Offset command to establish reference lines to help you draw the inside of the tub. This is where the Osnap overrides are useful. (See the sidebar "The Osnap Options" later in this chapter.)

You can use the Offset tool on the Home tab's Modify panel to make parallel copies of a set of objects, such as the lines forming the outside of your tub. Offset is different from the Copy command; while Offset allows only one object to be copied at a time, it can remember the distance you specify. The Offset option doesn't work with all types of objects. Only lines, arcs, circles, ellipses, splines, and 2D polylines can be offset.

Standard lines are best suited for the layout of the bathtub in this situation. In Chapter 6, you'll learn about two other objects, construction lines and rays, which are specifically designed to help you lay out a drawing. In this exercise, you'll use standard lines:

Figure 3.9. The completed layout

Now you'll begin to draw the inside of the tub, starting with the narrow end. You'll use your offset lines as references to construct the arcs that make up the tub. Also in this exercise, you'll set up some of the osnap options to be available automatically whenever AutoCAD expects a point selection. Here are the steps:

Look at the graphic symbols next to each of the osnap options in the Object Snap tab. These are the Osnap markers that appear in your drawing as you select osnap points. Each osnap option has its own marker symbol. As you use the osnaps, you'll become more familiar with how they work.

Figure 3.10. The Object Snap tab in the Drafting Settings dialog box

You've just set up the Endpoint, Midpoint, and Intersection osnaps to be on by default. This is called a Running Osnap; AutoCAD automatically selects the nearest osnap point without your intervention. Now let's see how a Running Osnap works:

The top image in Figure 3.12 shows the sequence I just described.

If you have several Running Osnap modes on (Endpoint, Midpoint, and Intersection, for example), pressing the Tab key cycles through those osnap points on the object. This feature can be especially useful in a crowded area of a drawing.

Next, you'll draw an arc for the left side of the tub:

It's easy for new users to select points inadvertently. If you accidentally select additional points after the last exercise and prior to step 1, you may not get the results described here. If this happens, issue the Arc command again; then, use the Endpoint osnap and select the endpoint of the last arc.

In step 5 of the previous exercise, the rubber-banding line indicates the direction of the arc. Be sure Ortho mode is off because Ortho mode forces the rubber-banding line and the arc in a direction you don't want. Check the status bar; if the Ortho tool is blue (on), press F8 or click the Ortho tool to turn off Ortho mode.

Now, you'll draw the bottom of the tub:

Next, create the right side of the tub by mirroring the left side:

Figure 3.13. The inside of the tub completed with the layout lines still in place

In this exercise, you were able to use osnaps in a Running Osnap mode. You'll find that you'll use osnaps constantly as you create your drawings. For this reason, you may want Running Osnaps on all the time. Even so, at times Running Osnaps can get in the way. For example, they may be a nuisance in a crowded drawing when you want to use a zoom window. The osnaps can cause you to select an inappropriate window area by automatically selecting osnap points.

Fortunately, you can toggle Running Osnaps on and off easily by clicking the Osnap tool in the status bar. If you don't have any Running Osnaps set, clicking the Osnap tool opens the Object Snap settings in the Drafting Settings dialog box, enabling you to select your osnaps.

Next, you'll erase the layout lines you created using the Offset command. But this time, you'll try selecting the lines before issuing the Erase command.

Follow these steps:

If you have problems selecting just the lines, try using a selection window to select single lines. (Remember, a window selects only objects that are completely within it.)

Figure 3.14. The drawing after erasing the layout lines

If you right-clicked to use the shortcut menu in step 2, you'll notice that you have several options besides Erase. You can move, copy, scale, and rotate the objects you selected. These options are similar to the tools on the Home tab's Modify panel in the way they act. But be aware that they act somewhat differently from the hot-grip options described in Chapter 2.

If you need more control over the selection of objects, you'll find the Add/Remove Selection Mode setting useful. This setting lets you deselect a set of objects within a set of objects you've already selected. While in Object Selection mode, enter R

The Osnap Options

Earlier, you made several of the osnap settings automatic so they're available without having to select them from the Osnap shortcut menu. Another way to invoke the osnap options is to type their keyboard equivalents while selecting points or to Shift+right-click and type the capital letter shown in the Osnap shortcut menu for the option you want to use.

The following is a summary (in alphabetic order) of all the available osnap options, including their keyboard shortcuts. You've already used many of these options in this chapter and in the previous chapter. Pay special attention to those options you haven't yet used in the exercises but may find useful to your style of work. The full name of each option is followed by its keyboard shortcut name in brackets. To use these options, you can enter either the full name or the abbreviation at any point prompt. You can also select these options from the pop-up menu obtained by Shift+clicking the right mouse button.

Apparent Intersection [app]

Selects the apparent intersection of two objects. This is useful when you want to select the intersection of two objects that don't actually intersect. You'll be prompted to select the two objects.

Center [cen]

Selects the center of an arc or a circle. You must click the arc or circle itself, not its apparent center.

Endpoint [endp or end]

Selects the endpoints of lines, polylines, arcs, curves, and 3D Face vertices.

Extension [ext]

Selects a point that is aligned with an imagined extension of a line. For example, you can pick a point in space that is aligned with an existing line but isn't on that line. To use that point, type ext

From [fro]

Selects a point relative to a picked point. For example, you can select a point that is 2 units to the left and 4 units above a circle's center. This option is usually used in conjunction with another osnap option, such as From Endpoint or From Midpoint.

Insertion [ins]

Selects the insertion point of text, blocks, Xrefs, and overlays.

Intersection [int]

Selects the intersection of objects.

Mid Between 2 Points [m2p]

Selects a point that is midway between two other points.

Midpoint [mid]

Selects the midpoint of a line or an arc. In the case of a polyline, it selects the midpoint of the polyline segment.

Nearest [nea]

Selects a point on an object nearest the pick point.

Node [nod]

Selects a point object.

None [non]

Temporarily turns off Running Osnaps.

Parallel [par]

Lets you draw a line segment that is parallel to another existing line segment. To use this option, type par

Perpendicular [per]

Selects a position on an object that is perpendicular to the last point selected.

Point Filters

Not really object snaps, but point-selection options that let you filter X, Y, or Z coordinate values from a selected point. (See Chapter 21 for more on point filters.)

Quadrant [qua]

Selects the nearest cardinal (north, south, east, or west) point on an arc or a circle.

Tangent [tan]

Selects a point on an arc or a circle that represents the tangent from the last point selected.

Temporary Track Point

Provides an alternate method for using the Object Snap Tracking feature described later in this chapter. (See Chapter 15 for more on Temporary Track Point.)

Sometimes you'll want one or more of these osnap options available as the default selection. Remember that you can set Running Osnaps to be on at all times. Type DS

The inside of the tub still has some sharp corners. To round out these corners, you can use the versatile Fillet tool on the Home tab's Modify panel. Fillet enables you to join lines and arcs end to end, and it can add a radius where they join so there is a smooth transition from arc to arc or line to line. Fillet can join two lines that don't intersect, and it can trim two crossing lines back to their point of intersection.

Another tool, called Chamfer, performs a similar function, but instead of joining lines with an arc, Chamfer joins lines with another line segment. Since they perform similar functions, Fillet and Chamfer occupy the same location on the Modify panel. If you don't see the Fillet tool, click the Chamfer flyout and select Fillet.

Continue with your tutorial by following these steps:

enter R

Figure 3.15. A view of the finished toilet and tub with the tub corners filleted

Osnap Tracking is like an extension of object snaps that enables you to align a point to the geometry of an object instead of just selecting a point on an object. For example, with Osnap Tracking, you can select a point that is exactly at the center of a rectangle.

In the following exercises, you'll draw a plan view of a bathroom sink as an introduction to the Osnap Tracking feature. This drawing will be used as a symbol in later chapters.

Drawing the Sink

You're ready to draw the sink. First, you'll draw the sink countertop. Then, you'll make sure Running Osnaps and Osnap Tracking are turned on. Finally, you'll draw the bowl of the sink.

Here are the steps for drawing the outline of the sink countertop:

1. 
2. 

3. At the prompt

   Specify first corner point or [Chamfer/Elevation/Fillet/Thickness/Width]:

enter 0,0

1. At the Specify other corner point or [Area/Dimensions/Rotation]: prompt, enter @2′4,1′6

   

2. Click Extents from the Zoom flyout on the View tab's Navigate panel or type Z

   

3. Use the Zoom Realtime tool in the Zoom flyout to adjust your view so it looks similar to the one shown in Figure 3.17. You can also enter Z

   

Figure 3.17. The view of the sink countertop after making some adjustments

When you draw the bowl of the sink, the bowl will be represented by an ellipse. You want to place the center of the ellipse at the center of the rectangle you've just drawn. To do this, you'll use the midpoint of two adjoining sides of the rectangle as alignment locations. This is where the Osnap Tracking tool will be useful.

You need to make sure the Object Snap tool is turned on and that the Midpoint Object Snap option is also turned on. Then you'll make sure Osnap Tracking is turned on. Use these steps:

1. 

2. Make sure the Midpoint check box in the Object Snap Modes group is selected.

3. Also make sure Object Snap On and Object Snap Tracking On are both selected. Click OK. You'll notice that the Osnap and Otrack buttons in the status bar are now in the on position.

Figure 3.18. The Object Snap tab in the Drafting Settings dialog box

Finally, you're ready to draw the ellipse:

1. 

2. At the Specify axis endpoint of ellipse or [Arc/Center]: prompt, type C, or right-click and choose Center from the shortcut menu. This enables you to select the center of the ellipse to start.

3. Move your cursor to the top, horizontal edge of the rectangle until you see the Midpoint tool tip.

4. Move the cursor directly over the Midpoint Osnap marker. Without clicking the mouse, hold the cursor there for a second until you see a small cross appear. Look carefully, because the cross is small. This is the Osnap Tracking marker (see Figure 3.19).

   

   Figure 3.19. The Osnap Tracking marker

   You can alternately insert and remove the Osnap Tracking marker by passing the cursor over the Osnap marker.

5. As you move the cursor downward, a dotted line appears, emanating from the midpoint of the horizontal line. The cursor also shows a small X following the dotted line as you move it (see Figure 3.20).

   

   Figure 3.20. A vertical dotted line appears.

6. Move the cursor to the midpoint of the left vertical side of the rectangle. Don't click, but hold it there for a second until you see the small cross. Now as you move the cursor away, a horizontal dotted line appears with an X following the cursor (see Figure 3.21).

   

   Figure 3.21. A horizontal dotted line appears.

7. Move the cursor to the center of the rectangle. The two dotted lines appear simultaneously and a small X appears at their intersection (see Figure 3.22).

   

   Figure 3.22. The vertical and horizontal dotted lines appear simultaneously.

8. With the two dotted lines crossing and the X at their intersection, click the left mouse button to select the exact center of the rectangle.

9. Point the cursor to the right, and enter 8

   

10. Point the cursor downward, and enter 6

    
    

    Figure 3.23. The completed bathroom sink

11. 

In this exercise, you saw how Osnap Tracking enables you to align two locations to select a point in space. Although you used only the Midpoint osnap setting in this exercise, you aren't limited to one osnap setting. You can use as many as you need to select the appropriate geometry. You can also use as many alignment points as you need, although in this exercise you used only two. If you like, erase the ellipse and repeat this exercise until you get the hang of using the Osnap Tracking feature.

As with all the other tools in the status bar, you can turn Object Snap Tracking on or off by clicking the Object Snap Track tool.

Using Grid mode is like having a grid under your drawing to help you with layout. In AutoCAD, Grid mode can also let you see the limits of your drawing because the grid can be set to display only within the limits setting of your drawing. Grid mode can help you visually determine the distances with which you're working in any given view. In this section, you'll learn how to control the grid's appearance. The F7 key toggles Grid mode on and off. You can also click the Grid tool in the status bar.

Using Object Snap Tracking and Polar Tracking Together

In addition to selecting as many tracking points as you need, you can use different angles besides the basic orthogonal angles of 0°, 90°, 180°, and 270°. For example, you can have AutoCAD locate a point that is aligned vertically to the top edge of the sink and at a 45° angle from a corner.

This can be accomplished by using the settings in the Polar Tracking tab of the Drafting Settings dialog box. (See the section "Setting the Polar Tracking Angle" earlier in this chapter.) If you set the increment angle to 45° and turn on the Track Using All Polar Angle Settings option, you'll be able to use 45° in addition to the orthogonal directions. You'll see firsthand how this works in Chapter 6.

To set up the grid spacing, follow these steps:

Figure 3.24. The Snap And Grid tab of the Drafting Settings dialog box

You can use the Gridunit system variable to set the grid spacing. Enter Gridunit

You can set the grid spacing by entering a value for Grid X spacing and Grid Y spacing. In the Grid Behavior group, the Display Grid Beyond Limits check box lets you determine whether the grid displays outside the limits of the drawing.

Click the Grid On check box to make the grid visible. Notice the F7 in parentheses: This tells you that the F7 function key also controls the Grid On/Off function. Click OK to dismiss the Drafting Settings dialog box and save your setting.

Once you've set up your grid, you can press F7 or click Grid in the status bar to turn the grid on and off. (You can also hold down the Ctrl key and press G.)

The Snap mode forces the cursor to move in steps of a specific distance. Snap mode is useful when you want to select points on the screen at a fixed interval. Two snap modes are available in AutoCAD: Grid Snap and Polar Snap. The F9 key toggles Grid Snap mode on and off, or you can click the Snap tool in the status bar. Follow these steps to access the Snap mode:

With Snap mode on, the cursor seems to move in steps rather than in a smooth motion. The Snap tool in the status bar appears blue, indicating that Snap mode is on. Press F9 or click Snap in the status bar (you can also hold down the Ctrl key and press B) to turn Snap mode on or off.

Note that you can use the Snapunit system variable to set the snap spacing. Enter ×Snapunit

Take a moment to look at the Drafting Settings dialog box. The other option in the Snap Spacing group enables you to force the X and Y spacing to be equal (Equal X And Y Spacing).

In the Snap Type group, you can change the snap and grid configuration to aid in creating 2D isometric drawings by clicking the Isometric Snap radio button. The PolarSnap option enables you to set a snap distance for the Polar Snap feature. When you click the PolarSnap radio button, the Polar Distance option at the middle left of the dialog box changes from gray to black and white to allow you to enter a Polar Snap distance.

You can also set up the grid to follow the snap spacing automatically. To do this, set the grid X and Y spacing to 0.