Rendering and Illumination - Autodesk AutoCAD 2013 Practical 3D Drafting and Design - page 326

Sky properties
This panel, available with photometric lighting, controls the sky background and sky
illumination. The small icon to the right of the Sky Properties tab displays the Ad-
just Sun & Sky Background dialog box with similar parameters as this panel and
with a preview area. Status allows us to activate sky lighting and/or the sky back-
ground, Intensity Factor allows us to increase or decrease the sky lighting intensity,
and Haze defines atmospheric effects.
On Horizon , we can define the horizon line and ground plane, namely, its absolute
Height , horizon Blur , and Ground Color . On Advanced , we define the sky color at
night, aerial perspective, and visibility distance. Finally, on Sun Disk Appearance ,
we specify the Sun visualization, namely, Disk scale , Glow intensity , and Disk in-
tensity .
Note
The Sun & Sky background can only be used with the perspective view.
With the perspective view, if Status is Off and cannot be modified, we may go to
the Adjust Sun & Sky Background box and turn it on there.