This node is the abstract base class for all vertex-based shape (geometry) nodes. It is used as a
repository for convenience functions for subclasses and to provide a type identifier to make it easy to
determine whether a shape is vertex-based. It contains one public field, the SoVertexProperty field.
All subclasses of this node draw objects constructed from vertices. If the vertexProperty field is non-
null and there are coordinates in the associated vertex property node, then those coordinates are used.
Otherwise the objects are drawn using the current coordinates in the state. The coordinates of the shape
are transformed by the current transformation matrix and are drawn with the current light model and
drawing style.
Subclasses that construct polygons from vertices may not render or pick correctly if any of their
polygons are self-intersecting or non-planar.
All vertex shape subclasses use the bounding box of the shape to determine default texture coordinates.
The longest dimension of the bounding box defines the S coordinates, and the next longest defines the T
coordinates. The value of the S coordinate ranges from 0 to 1, from one end of the bounding box to the
other. The T coordinate ranges between 0 and the ratio of the second greatest dimension of the bounding
box to the greatest dimension.
When a vertex-based shape is picked with an SoRayPickAction, a detail is always returned. If the shape is
composed of faces (such as SoFaceSet or SoTriangleStripSet), an SoFaceDetail is returned. If the shape
is composed of line segments (such as SoLineSet), an SoLineDetail is returned. If the shape is composed
of points (such as SoPointSet), an SoPointDetail is returned. Note that the type of detail returned is
not affected by the current drawing style.
Similarly, each class of vertex-based shape invokes appropriate callbacks if those callbacks are
registered with the SoCallbackAction. Shapes made of faces invoke triangle callbacks for each generated
triangle. (Faces may be triangulated to create these triangles.) Shapes made of line segments invoke
line segment callbacks for each segment, and shapes made of points invoke point callbacks.
The subclass SoIndexedShape is a base class for vertex-based shapes that index into the current set of
coordinates. The subclass SoNonIndexedShape is a base class for vertex-based shapes that use the current
coordinates in order.