Figure 24.1 A set of emitter markers indicating the emitter's location, minimum-range ellipsoid, and maximum-range ellipsoid.
24fig01.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 [
    # Emitter marker
        Shape {
            appearance Appearance {
                material Material {
                    diffuseColor  0.0 0.0 0.0
                    emissiveColor 1.0 1.0 1.0
                }
            }
            geometry Sphere { radius 0.25 }
        },
    # Minimum range ellipsoid (circle) marker
        DEF MinMarker Shape {
            appearance Appearance {
                material Material {
                    diffuseColor  0.0 0.0 0.0
                    emissiveColor 1.0 0.0 0.5
                }
            }
            geometry Cylinder {
                radius 5.0
                height 0.01
                side   FALSE
                bottom FALSE
            }
        },
    # Maximum range ellipsoid (circle) marker
        DEF MaxMarker Shape {
            appearance Appearance {
                material Material {
                    diffuseColor  0.0 0.0 0.0
                    emissiveColor 0.5 0.0 1.0
                }
            }
            geometry Cylinder {
                radius 10.0
                height 0.001
                side   FALSE
                bottom FALSE
            }
        },
    ]
}