Graphics Programs Reference
In-Depth Information
Weblight:
A cross between a point light and a spotlight. Weblights are avail-
able only when using photometric lights, and the way they emit light is determin-
ed by an IES file. IES files are provided by lighting companies for use in products
like AutoCAD to mimic the lights that they manufacture.
AutoCAD and I both strongly advise against using distant lights when using
photometric lighting. If you decide to ignore this warning, make sure to turn down
the intensity factor of the distant light to avoid washing out your rendering.
Point lights, spotlights, and weblights can be selected and edited directly in a
drawing because a glyph is displayed to show where the light is located. Distant
lights do not have an associated glyph. (A
glyph
is a nonprinting object displayed
in a drawing that enables you to select an object that is not part of the actual
model.)
Figure 23-3:
Lighting primitives with the four types of user-defined lights.
Shadows . . . or no shadows?
AutoCAD allows you to define lights that can't generate shadows. This might seem illo-
gical because shadows are cast when light is obscured by an object. This is important
