[JAVA3D] Adding TransformGroup after compile()

[SW Keum]

hi. 

after compile() my objRoot (BranchGroup), i detached some children and attached new 
ones with picking. but when i try to pick the new child object, i got these error 
messages.

Exception occurred during Behavior execution:
java.lang.IllegalStateException: Picking can only work if BranchGroup is alive
        at javax.media.j3d.BranchGroup.pickClosest

The problem here is, that i can add the child to the existing objRoot, but i cannot 
make it alive.

the code is as follows. 

class MyClass ...
{
    SimpleUniverse su;
    su = ...;
    public void createBranchGroup()
    {
        ...
        ...
        objRoot.addChild(new myBranchGroup(su));
    }
}

class myBranchGroup extends BranchGroup(SimpleUniverse su)
{
     .....
     TransformGroup trans = new TransformGroup();
     this.addChlid(trans);
    PickTranslateBehavior pick = new PickTranslateBehavior(this, new Canvas3D   
(SimpleUniverse.getPreferredConfiguration()), new BoundingBox() );
    this.addChild(pick);
}


i setup needed capability bits (CHILDREN_READ, CHILDREN_WRITE, ENABLE_PICK_REPORTING, 
etc). but this code generate the error before. how can i add a child and make it 
alvie?
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