When the proper capability is set,the content of virtual world can be modified at runtime. So if we can change the content continuously with time lapsing, we can add the animation behavior to the virtual object.

Java3D provides some Interpolator classes to do this work.Through using the subclasses of Interpolator class, we can add many animation behaviors to the virtual object.

This program illustrates how to add the rotation behavior to the Cube by RotationInterpolator class.

 public class RotationBehavior extends JFrame {
  public RotationBehavior() {

  public BranchGroup createSceneGraph() {
    // Create the root of the branch graph
    BranchGroup objRoot = new BranchGroup();
    // Create the transform group node with the proper capiability
    TransformGroup objSpin=new TransformGroup();
    objSpin.addChild(new ColorCube(0.4));
    // Create time varying function to drive the animation
    Alpha rotationAlpha=new Alpha(-1,4000);
    // Create a new Behavior object that performs the desired
    // operation on the specified transform object and add it into
    // the scene graph.
    RotationInterpolator rotator=new RotationInterpolator(rotationAlpha,objSpin);
    //a bounding sphere specifies a region a behavior is active
    BoundingSphere bounds=new BoundingSphere();

    return objRoot;
  public static void main(String[] args){