Figure 20.14 The sunlight direction animated using a PositionInterpolator node.
20fig14.wrl	Click on the image to view the VRML scene.

#VRML V2.0 utf8
# The VRML 2.0 Sourcebook
# Copyright (c) 1997
# Andrea L. Ames, David R. Nadeau, and John L. Moreland
Group {
    children [
    # Animated sunlight
        DEF SunLight DirectionalLight {
            direction  0.8 -0.2 -0.2
            intensity 1.0
            ambientIntensity 0.5
            color 1.0 0.6 0.0
        },
    # Animation clock
        DEF Clock TimeSensor {
            cycleInterval 10.0
            loop TRUE
        },
    # Animation directions
        DEF LightDirection PositionInterpolator {
            key [ 0.0, 0.5, 1.0 ]
            keyValue [ 0.8 -0.2 -0.2, 0.0 -1.0 -0.2, -0.8 -0.2, -0.2 ]
        },
    # Animation colors and ambient intensity
        DEF LightColor ColorInterpolator {
            key [ 0.0, 0.5, 1.0 ]
            keyValue [ 1.0 0.6 0.0, 1.0 0.9 0.7, 1.0 0.3 0.1 ]
        },
        DEF LightAmbient ScalarInterpolator {
            key [ 0.0, 0.5, 1.0 ]
            keyValue [ 0.3, 0.7, 0.2 ]
        },
    # Vaulted ceiling and columns
        Inline {
            url "vaulted.wrl"
            bboxCenter 0.0 1.0 0.0
            bboxSize   6.0 2.0 6.0
        },
    # Floor
        Shape {
            appearance Appearance {
                material Material { }
            }
            geometry Box { size 16.0 0.01 16.0 }
        }
    ]
}
ROUTE Clock.fraction_changed       TO LightDirection.set_fraction
ROUTE Clock.fraction_changed       TO LightColor.set_fraction
ROUTE Clock.fraction_changed       TO LightAmbient.set_fraction
ROUTE LightDirection.value_changed TO SunLight.set_direction
ROUTE LightColor.value_changed     TO SunLight.set_color
ROUTE LightAmbient.value_changed   TO SunLight.set_ambientIntensity