512
AutoCAD and Its Applications—Advanced
Copyright Goodheart-Willcox Co., Inc.
The
Rotation:
text box provides the option of rotating the gradient. Pick the
OK
button
to close the
Background
dialog box. Next, save the view, set the view current, and pick
the
OK
button to close the
View Manager
dialog box.
Convincing, clear blue skies can be simulated using the
Gradient
option. Initially,
set the Top, Middle, and
Bottom
color values the same. Then, change the lightness
(luminance) in the
True Color
tab in the
Select Color
dialog box. Preview the back-
ground and make adjustments as needed.
Using an Image as a Background
An image can be used as a background. This technique can be used to produce
realistic or imaginative settings for your models. If you select
Image
in the drop-down
list in the
New View/Shot Properties
dialog box, the
Background
dialog box is displayed
with
Image
selected and a blank image displayed in the
Preview
area. To locate the
image fi le, pick the
Browse…
button to display a standard open dialog box. These
image fi le types may be used for the background: TGA, BMP, PNG, JFIF (JPEG), TIFF,
GIF, and PCX. Locate the image fi le and select Open. See Figure 17-26.
Once the image fi le is selected, it must be adjusted. The
Preview
area of the
Background
dialog box shows the image with a preview of a drawing sheet. This
drawing sheet indicates how the image is going to be positioned in the view. Pick
the
Adjust Image…
button to open the
Adjust Background Image
dialog box. See
Figure 17-27.
In the
Image position:
drop-down list, pick how the image is applied to the view-
port. The
Center
option centers the image in the view without changing its aspect ratio
or scale. The
Stretch
option centers the image and stretches or shrinks it to fi ll the entire
view. This is one way to plot an image fi le from AutoCAD. The
Tile
option keeps the
image at its original size and shape, but moves it to the upper-left corner and dupli-
cates it, if needed, to fi ll the view.
After the image is positioned, use the sliders to adjust it further. The sliders are
disabled if
Stretch
is selected in the
Image position:
drop-down list. The slider function
is based on which radio button is picked above the image:
• Offset. The sliders move the image in the X or Y direction.
• Scale. The sliders scale the image in the X or Y direction. This may distort the
image if it is scaled too much in one direction. To prevent distortion, check the
Maintain aspect ratio when scaling
check box at the bottom of the dialog box.
The
Reset
button is located at the bottom-right corner of the preview pane. Picking
this button returns the scale and offset settings to their original values.
Selected
image file
Image
is
selected
Pick to
adjust the
image
Pick to
locate an
image file
Drawing
sheet
preview
Figure 17-26.
Setting an image as
the background.