Defining a UCS
1. Start AutoCAD and create a new file called Barcelon.
2. Set up your drawing as an architectural drawing with a scale
of 1”=1’-0” on an 81/2 x 11” sheet. Set the upper-right cor-
ner of the limits to 132x102. If you’re a metric user, you’ll
be drawing the chair at a scale of 1 to 10 on an A4 sheet.Your
Your work area should be 297 x 210, which is the equivalent of a
297cm by 210cm area.
TIP: If you are a metric user and you prefer to work in millimeters,
You can set the upper-right corner of the limits to 2970, 2100.Then,
when the book specifies a length or coordinate , multiply the specified
value by 10. For example, 50cm becomes 500mm. Coordinate 50,50
becomes 500,500. Your scale factor would also changed to 100.
3. Choose View>Zoom>All or type Z, press Enter, type A, and press
Enter again.
4. To draw the seat of the chair, click the Rectangle tool on the Draw toolbar.
Draw a rectangle (I draw a box) measuring 20” in the x-axis and 30” in the y-axis. Position the rectangle so the lower left corner is at the coordinate 2’-0”,2’-0”(see the top image of Figure 11.2) . Metric users should draw a rectangle that is 50cm by 76cm with its lower-left corner at coordinate 50,50.
5. To draw the back of the chair, draw another rectangle (I draw a box and I enter 3 at Specify height of the box) 17” in the x- axis,and 30” in the y-axis, just to the right of the previous rectangle (see the top image of Figure 11.2). Metric users should make this rectangle 43cm by 76cm.
6. Choose View> 3D Views>SW Isometric to see a 3D view from the lower left of the rectangles, as shown in the bottom image of Figure 11.2.
7. Select the two rectangles, and then click the Properties tool on the Standard
Toolbar. (I see Properties on: Right click; View>Toolbar>Properties;
Modify>Properties).
8. In the Properties dialog box, enter 3 in the Thickness setting and click OK. This
setting gives the seat and back a thickness of 3”. (I enter 3 at Specify height of the box) Metric users should make the thickness 7.6cm.
9. Close the Properties dialog box.
10. Zoom out a bit and give yourself some room to work.
Next you will define a UCS that is aligned with one side of the seat.
1. Right-click any toolbar, and at the pop-up menu, select UCS. The UCS toolbar apears.
2. Click the Display UCS Dialog tool in the UCS toolbar.
The UCS dialog box appears.
3. Select the Orthographic UCSs tab to view a se of preefined UCSs.
4. Select Front in the list box. Figure 11.3 shows the orientation of the front UCS.
5. Click the Set Current button to make the Front UCS the curren one.
6. Click OK to close the dialog box.
The Orthographic UCSs tab offers a set o predifined UCSs for each of the six standard orthographic projection planes.Figure 11.3 shows these UCSs in relation to the World Coordinate System. You can also accessthese orthographic UCSs from the Tools>Orthographic UCS cascading menu, or from the UCS dialog box.
Because a good part of 3D involves drawing in these orthographic planes, AutoCAD supplies these ready-made UCS orientations for quick access. But you aren't limited to these six orientations by any means. If you are familiar with mechanical drafting , you'll see that the orthographic UCSs correspond to the typical orthographic projections used in mechanical drafting.If you are an architect, the Front, Left, Back, and Right UCSs correspond to the south, west, north, and east elevationsof a building. Before you continue building the chair model, you'll want to move the UCS to the surfaceon which you wil be working. Right now, the UCS has its origin located in the same place as the WCS origin. You can move a UCS so that its origin is anywhere in the drawing where it's needed.
1. Click the Origin UCS tool in theUCS toolbar.
2. Use the Endpoint Osnap and click the bottom-front corner of the chair seat, as shown in
Figure 11.4. The UCS icon moves to indicate its new origin's location.
The operation you just performed created a new UCS based on the Front UCS you selected from the UCS dialog box. Now, as you move your cursor, you'll see that the origin of the UCS icon corresponds to a 0,0 coordinate. Although you have a new UCS, the WCS still exists, and you can always return to it when you need to.
Saving a UCS
Once you've gone through the work of creating a UCS, you may want to save it. Especially if you
think you'll wan to come back to it later on. Here's how to save a UCS.
1. Click Display UCS Dialog box n the UCS toolbar. You can also choose Tools>Named UCS. The UCS dialog box appears.
2. Make sure the Named UCSs tab is selected, and then highlight the Unnamed option in the Current UCS list box.
1. Start AutoCAD and create a new file called Barcelon.
2. Set up your drawing as an architectural drawing with a scale
of 1”=1’-0” on an 81/2 x 11” sheet. Set the upper-right cor-
ner of the limits to 132x102. If you’re a metric user, you’ll
be drawing the chair at a scale of 1 to 10 on an A4 sheet.Your
Your work area should be 297 x 210, which is the equivalent of a
297cm by 210cm area.
TIP: If you are a metric user and you prefer to work in millimeters,
You can set the upper-right corner of the limits to 2970, 2100.Then,
when the book specifies a length or coordinate , multiply the specified
value by 10. For example, 50cm becomes 500mm. Coordinate 50,50
becomes 500,500. Your scale factor would also changed to 100.
3. Choose View>Zoom>All or type Z, press Enter, type A, and press
Enter again.
4. To draw the seat of the chair, click the Rectangle tool on the Draw toolbar.
Draw a rectangle (I draw a box) measuring 20” in the x-axis and 30” in the y-axis. Position the rectangle so the lower left corner is at the coordinate 2’-0”,2’-0”(see the top image of Figure 11.2) . Metric users should draw a rectangle that is 50cm by 76cm with its lower-left corner at coordinate 50,50.
5. To draw the back of the chair, draw another rectangle (I draw a box and I enter 3 at Specify height of the box) 17” in the x- axis,and 30” in the y-axis, just to the right of the previous rectangle (see the top image of Figure 11.2). Metric users should make this rectangle 43cm by 76cm.
6. Choose View> 3D Views>SW Isometric to see a 3D view from the lower left of the rectangles, as shown in the bottom image of Figure 11.2.
7. Select the two rectangles, and then click the Properties tool on the Standard
Toolbar. (I see Properties on: Right click; View>Toolbar>Properties;
Modify>Properties).
8. In the Properties dialog box, enter 3 in the Thickness setting and click OK. This
setting gives the seat and back a thickness of 3”. (I enter 3 at Specify height of the box) Metric users should make the thickness 7.6cm.
9. Close the Properties dialog box.
10. Zoom out a bit and give yourself some room to work.
Next you will define a UCS that is aligned with one side of the seat.
1. Right-click any toolbar, and at the pop-up menu, select UCS. The UCS toolbar apears.
2. Click the Display UCS Dialog tool in the UCS toolbar.
The UCS dialog box appears.
3. Select the Orthographic UCSs tab to view a se of preefined UCSs.
4. Select Front in the list box. Figure 11.3 shows the orientation of the front UCS.
5. Click the Set Current button to make the Front UCS the curren one.
6. Click OK to close the dialog box.
The Orthographic UCSs tab offers a set o predifined UCSs for each of the six standard orthographic projection planes.Figure 11.3 shows these UCSs in relation to the World Coordinate System. You can also accessthese orthographic UCSs from the Tools>Orthographic UCS cascading menu, or from the UCS dialog box.
Because a good part of 3D involves drawing in these orthographic planes, AutoCAD supplies these ready-made UCS orientations for quick access. But you aren't limited to these six orientations by any means. If you are familiar with mechanical drafting , you'll see that the orthographic UCSs correspond to the typical orthographic projections used in mechanical drafting.If you are an architect, the Front, Left, Back, and Right UCSs correspond to the south, west, north, and east elevationsof a building. Before you continue building the chair model, you'll want to move the UCS to the surfaceon which you wil be working. Right now, the UCS has its origin located in the same place as the WCS origin. You can move a UCS so that its origin is anywhere in the drawing where it's needed.
1. Click the Origin UCS tool in theUCS toolbar.
2. Use the Endpoint Osnap and click the bottom-front corner of the chair seat, as shown in
Figure 11.4. The UCS icon moves to indicate its new origin's location.
The operation you just performed created a new UCS based on the Front UCS you selected from the UCS dialog box. Now, as you move your cursor, you'll see that the origin of the UCS icon corresponds to a 0,0 coordinate. Although you have a new UCS, the WCS still exists, and you can always return to it when you need to.
Saving a UCS
Once you've gone through the work of creating a UCS, you may want to save it. Especially if you
think you'll wan to come back to it later on. Here's how to save a UCS.
1. Click Display UCS Dialog box n the UCS toolbar. You can also choose Tools>Named UCS. The UCS dialog box appears.
2. Make sure the Named UCSs tab is selected, and then highlight the Unnamed option in the Current UCS list box.
3. Right-click Unnamed, and then select Rename from the list box. Thae item change to allow editing.
4. Type 3DSW an press Enter for the name of your new UCS.
5. Click OK to exit the dialog box.
Working in a UCS
1. Click th seat back to expose his grips.
2. Click the bottom grip, as shown in the first image of Figure 11.5
3. Right-click the mouse to open the Grip Edit pop-up menu.
4. Select Rotate from the menu. Notice how the seat back now rotates with the movement of the cursor. Take a moment to play with this notation; it may take a while to grow accustomed to it. Because thi is an Isometric view, you can get an optical illusion effect.
5. Type 80 and press Enter to rotate the seat back 80 degree. Your view will look like the second image of Figure 11.5.
6. Click the bottom grip shown in the second image of Figure 11.5
7. Right-click the mouse again and select Move.
8. Using the Endpoint Osnap, click the top corner of the chair seat, as shown in the second image of Figure 11.5, to join the chair back to the seat.
9. Click both the chair seat an back; then, click the bottom corner grip of the seat, as shown in the third image of Figure 11.5.
10. Right-click the mouse; then, at the Grip Edit pop-up menu, click Rotate.
11. Enter -10 and press Enter to rotate both the seat and back minus 10 degrees. Pres the Esc key to clear the grips. Your chair will look like Figure 11.6.
The new UCS orientation enabled you to use the grips to adjust the chair seat an back.
Now, to finish th chair seat and back, add a 3D Face to their top and bottom surfaces.
1. To help you visualize what's going on a yo add the 3D Face, turn on the Hidden Shade mode by choosing View>Shade>Hidden. Or, if you have the Shade toolbar open, you can click the Hidden tool.
2. Click the 3D Face button on the Surfaces toolbar, or choose Draw>Surfaces>3D Face, to draw a surface over the top sides of the chair seat and back. Start the 3D Face in the left-most corner of the seat and work in a counterclockwise fasion.
NOTE
To dispaly the Surfaces toolbar, right-click any toolbar, and then choose Surfaces from the Toolbars dislog box.
3. Add the 3D Faces to the bottom of the chair seat and to the chair back, as shoiwn in Figure 11.7.
4. when you're finished adding the 3D Faces, turn off the Hidden Shade moder. Choose View>Shade>2D Wireframe.
Normally, when you are picking points for 3D Faces, it doesn't matter where you begin selectin points. But for the purpose of this chapter, you selected points for the seat's 3D Face starting at the left-most corner and working in a counterclockwise fashion. The way you create the chair seat will influence the acton for some UCS command options that you'll use later in this chapter.
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