Figure 19.25a A smooth-shaded half column using custom normals. Compare with Figure 19.25b.
19fig25a.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 [
        Shape {
            appearance Appearance {
                material Material { }
            }
            geometry IndexedFaceSet {
                coord Coordinate {
                    point [
                        -2.00  3.00 0.00,
                        -2.00 -3.00 0.00,
                        -1.41  3.00 1.41,
                        -1.41 -3.00 1.41,
                         0.00  3.00 2.00,
                         0.00 -3.00 2.00,
                         1.41  3.00 1.41,
                         1.41 -3.00 1.41,
                         2.00  3.00 0.00,
                         2.00 -3.00 0.00,
                    ]
                }
                coordIndex [
                    0, 1, 3, 2,   -1,
                    2, 3, 5, 4,   -1,
                    4, 5, 7, 6,   -1,
                    6, 7, 9, 8,   -1,
                ]
                normalPerVertex TRUE
                normal Normal {
                    vector [
                        -1.00 0.00 0.00,
                        -0.71 0.00 0.71,
                         0.00 0.00 1.00,
                         0.71 0.00 0.71,
                         1.00 0.00 0.00,
                    ]
                }
                normalIndex [
                    0, 0, 1, 1,   -1,
                    1, 1, 2, 2,   -1,
                    2, 2, 3, 3,   -1,
                    3, 3, 4, 4,   -1,
                ]

            }
        }
    ]
}