SceneGraphStreamReader/ Writer Problem

Hi All,

I try to save the scenegraph (include RotPosPathInterpolator node) by using SceneGraphStreamWriter. After i loading it again. I got following error meessage. Please give me some advice. Thanks.

P.S. There are no problems if the scenegraph didn't contain behavior node.

java.lang.NullPointerException
at javax.media.j3d.Transform3D.set(Transform3D.java:1846)
at javax.media.j3d.TransformInterpolator.<init>(TransformInterpolator.java:89)
at javax.media.j3d.PathInterpolator.<init>(PathInterpolator.java:122)
at javax.media.j3d.RotPosPathInterpolator.<init>(RotPosPathInterpolator.java:75)
at com.sun.j3d.utils.scenegraph.io.state.javax.media.j3d.RotPosPathInterpolatorState.createNode(RotPosPathInterpolatorState.java:109)
at com.sun.j3d.utils.scenegraph.io.state.javax.media.j3d.SceneGraphObjectState.readObject(SceneGraphObjectState.java:151)
at com.sun.j3d.utils.scenegraph.io.state.javax.media.j3d.NodeState.readObject(NodeState.java:71)
at com.sun.j3d.utils.scenegraph.io.state.javax.media.j3d.BehaviorState.readObject(BehaviorState.java:87)
at com.sun.j3d.utils.scenegraph.io.state.javax.media.j3d.InterpolatorState.readObject(InterpolatorState.java:65)
at com.sun.j3d.utils.scenegraph.io.state.javax.media.j3d.TransformInterpolatorState.readObject(TransformInterpolatorState.java:71)
at com.sun.j3d.utils.scenegraph.io.retained.Controller.readObject(Controller.java:340)
at com.sun.j3d.utils.scenegraph.io.state.javax.media.j3d.GroupState.readObject(GroupState.java:86)
at com.sun.j3d.utils.scenegraph.io.state.javax.media.j3d.TransformGroupState.readObject(TransformGroupState.java:70)
at com.sun.j3d.utils.scenegraph.io.retained.Controller.readObject(Controller.java:340)
at com.sun.j3d.utils.scenegraph.io.state.javax.media.j3d.GroupState.readObject(GroupState.java:86)
at com.sun.j3d.utils.scenegraph.io.state.javax.media.j3d.TransformGroupState.readObject(TransformGroupState.java:70)
at com.sun.j3d.utils.scenegraph.io.retained.Controller.readObject(Controller.java:340)
at com.sun.j3d.utils.scenegraph.io.state.javax.media.j3d.GroupState.readObject(GroupState.java:86)
at com.sun.j3d.utils.scenegraph.io.retained.Controller.readObject(Controller.java:340)
at com.sun.j3d.utils.scenegraph.io.retained.StreamControl.readBranchGraph(StreamControl.java:148)
at com.sun.j3d.utils.scenegraph.io.SceneGraphStreamReader.readBranchGraph(SceneGraphStreamReader.java:91)
at loader$2.actionPerformed(loader.java:222)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)