This node defines a set of 3D coordinates to be used by subsequent vertex-based shape nodes (those derived from
SoVertexShape) or shape nodes that use them as control points (such as NURBS curves and surfaces). Coordinates
are specifed as rational 4-vectors; the corresponding 3D point is computed by dividing the first three components by the fourth. This node does not produce a visible result during rendering; it simply
replaces the current coordinates in the rendering state for subsequent nodes to use.
This node exists primarily for use with NURBS curves and surfaces. However, it can be used to define coordinates for
any vertex-based shape.