The Pill handle is used to control all the parameters to a capture
region SOP in an interactive manner.  It creates a pill which can be
manipulated to alter the relevant parameters.

Note: For brevity, a * is used in the parameters where either "bot" or
"top" would be present.  bot refers to the bottom half of the capture
pill, and top to the top half.

Parameters:

    *height        - The distance from the center where the end cap starts.
    *rx, cr_*ry    - The radius of the end cap in the x & y directions.
    *rz            - The radius of the end cap in the direction of the pill.
    colorb, colorg, colorr - The colour to draw the handle in.
    orient         - The main axis of the pill.
    tx, ty, tz     - The center of the pill.
    length         - The native length of the bone.

See Also: Bone
