2012

available only when the Style option of Snap mode is set to Isometric (see
DSETTINGS).
NOTE To represent concentric circles, draw another ellipse with the same center
rather than offsetting the original ellipse. Offsetting produces an oval-shaped spline
that does not represent foreshortened distances as you would expect.
Add Lighting to Your Model
Lighting can be added to a scene to create a more realistic rendering.
Overview of Lighting
Lighting adds the finishing touch to the scene.
Default Lighting
When there are no lights in a scene, the scene is shaded with default lighting.
Default lighting is derived from two distant sources that follow the viewpoint
as you move around the model. All faces in the model are illuminated so that
they are visually discernible. You can control brightness and contrast, but you
do not need to create or place lights yourself.
When you insert custom lights or add sunlight, you can disable the default
lighting. You can apply default lighting to the viewport only; at the same
time, you can apply custom lights to the rendering.
Standard Lighting Workflow
You add lights to give the scene a realistic appearance. Lighting enhances the
clarity and three-dimensionality of a scene. You can create point lights,
spotlights, and distant lights to achieve the effects you want. You can move
or rotate them with grip tools, turn them on and off, and change properties
such as color and attenuation. The effects of changes are visible in the viewport
in real time.
Spotlights and point lights are each represented by a different light glyph (a
symbol in the drawing showing the location of the light). Distant lights and
the sun are not represented by glyphs in the drawing because they do not
have a discrete position and affect the entire scene. You can turn the display
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