Javra: a simple, extensible Java package for VRML

Javra is a Java package for handling VRML scene graphs; it operates either stand-alone or in combination with a VRML browser. The combination of Javra and a VRML browser forms an effective start for generating 3D interactive applications. With Javra a VRML scene graph can be handled: both classes for VRML nodes and methods for setting and getting the fields of these nodes are supplied. Furthermore, VRML events generated, for instance, after a user action, can be caught and handled in Javra. The Javra node classes have an inheritance structure which allows strict compile time type checking of the construction of the scene graph. The programmer interface is intended to be simple enough to be used by students of an introductory programming course. The node classes are generated completely automatically, resulting in a robust package. The automatic code generation can also be used to create custom Java packages for programmer-defined VRML prototypes, effectively resulting in the extension of the set of Javra nodes.