Points, lines and mesh faces allow authors to build a complete variety of geometry.
Complex shapes are hard to build with primitive shapes (for example: terrain, animals, plants, machinery).
Instead, build shapes out of atomic components: points, lines, and polygon faces.
Shape building is like a 3D connect-the-dots game: place dots at 3D locations, and connect-the-dots to form shapes
A coordinate specifies a 3D dot location, measured relative to a coordinate system origin.
A geometry node then specifies how to connect the dots: for example,
PointSet, IndexedLineSet, or IndexedFaceSet.
Animation is accomplished using a CoordinateInterpolator node.
These X3D scenes are adapted directly from the
original VRML 2.0 Sourcebook chapter examples.
Introduction to VRML97 SIGGRAPH98 course notes.