Figure 19.24b Two half columns with a visible seam caused by inaccuracies in the crease-angle method of computing normals. Compare with Figure 19.24a.
19fig24b.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 [
        Transform {
            rotation 0 1 0  1.570795
            children [
                DEF halfCol Inline { url "colca1.wrl" }
            ]
        }
        Transform {
            rotation 0 1 0  -1.570795
            children [
                USE halfCol
            ]
        }
    ]
}