Animation with Interpolator - only after a counter has a certain value

Hey guys,

i hope someone can help me. In my Project wich is a little 3d game I have a building with some rooms and doors. now i want to automatically open the doors by animations, when my camera is in front of them. I´ve already wrote the animation with an rotation interpolator to open the first door. but the interpolator starts immediatly after the programm starts. Until now i didn´t find a solution to start the animation only when i want to.
The plan is everytime when the camera achieved one door a counter counts up and the animation for exactly this specific door is activated.
Here is my code:

public void eingangstuer2()
{
	
	ColorCube colorcube = new ColorCube();
	TransformGroup neu2 = new TransformGroup();
	TransformGroup t = new TransformGroup();
	
	t.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
	
	Transform3D tgTuer4 = new Transform3D();
	transformgroup.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
	
	
	tgTuer2.setScale(new Vector3d( 0.0365, 0.1, 0.005 ));
	
	tgTuer2.setTranslation(new Vector3f(0.03f,0f,0f));
	transformgroup .setTransform(tgTuer2);
	

	tgTuer4 .setTranslation(new Vector3f(-0.06f,-0.4425f,-5.057f));
	neu2.setTransform(tgTuer4);
	


	Alpha rotationTuer =new Alpha (1,50000);
	rotationTuer.setStartTime(System.currentTimeMillis());
    
	
	
	
	RotationInterpolator wegTuer = new RotationInterpolator(rotationTuer, t);
	
	wegTuer.setMinimumAngle((float)Math.toRadians(0));
	wegTuer.setMaximumAngle((float)Math.toRadians(180));
	wegTuer.setEnable(false);
	wegTuer.setSchedulingBounds(new BoundingSphere(new Point3d(), 1000));
	rotationTuer.finished();
   

	
	t.addChild(wegTuer);
	
	transformgroup.addChild(colorcube);
	t.addChild(transformgroup);
	
	neu2.addChild(t);
	
	


	BranchGroup branchtuer2 = new BranchGroup();
	
	branchtuer2.addChild(neu2);

	u.addBranchGraph(branchtuer2);

	
}

 else if(e.getKeyChar() == '8'){
			 
			
			 
			eingangstuer2();
		
			}
			
		 }	
		

Thanks in advance