Rendering and Materials - AutoCAD 2011 and AutoCAD LT 2011: No Experience Required - page 930

Controlling the Background of the Rendering
The following are some of the options you can set when choosing a background
for the rendering:
the AutoCAD Background This is what you used for the preliminary rendering.
Another Solid Color Use the slider bars to choose another solid color.
Gradient You can use varying colors (usually light to dark) blended together.
image You can supply or choose a bitmap image.
Sun & Sky Background You can use a computer-generated sky. This background
has the option of introducing additional ambient illumination into the scene.
You'll use the Sun & Sky Background option with the Illumination option here:
1. Click the View tab, and then click the Named Views button in the View
panel to open the View Manager dialog box.
2. Expand the Model Views entry, and then select Cam Southeast.
3. Expand the drop-down list for the Background Override entry in the
General rollout, and then choose Sun & Sky, as shown in Figure 17.22.
FiGuRE 17.22 The Cam Southeast camera selected in the View Manager
dialog box
Doing so opens the Adjust Sun & Sky Background dialog box, as
shown in Figure 17.23.