band_colors (
        plist,
        point_colors,
        segment_colors,
        segment_subdivisions,
        band_length,
        )

Calculate point and segment colors for an interpolated set of points. Point colors are extended to interpolated points and segments within band_length/2 arc distance.

band_points ( arcs,  band_length )

Count points within band_length/2 of each end of an arc.

cylinder_node (
        p1,
        p2,
        radius,
        rgb,
        )

Return VRML node for a cylinder with axis specified by end points.

vrml_color_indexing ( colors )

Return VRML strings for color table and color index list.

vrml_lines ( points,  colors )

Return VRML string to draw a piecewise linear curve.

vrml_nurbs_spline ( points,  rgb )

Use VRML NurbsCurve extension to create spline. Curve will not pass through points and will not extend to the end points. This is taken from the Chimera Ribbon extension.

vrml_overhauser_spline (
        points,
        rgb,
        radius,
        segment_subdivisions,
        )

Return VRML string drawing a piecewise linear approximation to an Overhauser spline. An Overhauser spline uses cubic segments that join at the given points and have continuous tangent vector. For the end segments I use a quadratic curve.

vrml_point_indexing ( points )

Return VRML strings for xyz coordinate table and point index list.

vrml_tube (
        points,
        point_colors,
        segment_colors,
        radius,
        )

Return VRML string to that draws a tube. Cylinders are drawn between consecutive points with spheres at each point to join cylinders at a bend and to cap the ends.