3D Graphics Programming with QuickDraw 3D 1.5.4
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Point Lights
Data Format
Point3D location
Attenuation attenuation
Boolean castsShadows
- location
- The location of the source of the point light.
- attenuation
- This structure determines the amount that the intensity of the light diminishes over distance. See the section "Attenuation and Fall-Off Values" for a description of this structure.
- castsShadows
- A value of True specifies that objects illuminated by the light are to cast shadows; a value of False specifies that objects illuminated by the light are not to cast shadows.
Description
A point light is a light that emits rays in all directions from a specific point source. A point light may suffer attenuation over distance and may cast shadows.
Some style objects also specify whether or not objects in a scene shall receive shadows. However, objects in the scope of a receive shadows style set to False do not receive shadows, regardless of whether they are also appropriately situated to receive shadows from a light set to cast shadows.
Child Objects
Light data (optional). If no child object is specified, the light should have the properties specified in the default setting of a light data object.
Example
BeginGroup ( DisplayGroup ( ) )
Triangle ( ... )
Box ( ... )
Container (
PointLight (
-10, 1, -1 # location
1 0 1 # attenuation
True # casts shadows
)
LightData ( ... )
)
EndGroup ( )
© 1997 Apple Computer, Inc.
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