How to use the klampt.vis.add function in Klampt

#the next line latches the current configuration in the PID controller...
	sim.controller(0).setPIDCommand(robot.getConfig(),robot.getVelocity())
	
	#this code uses the GLSimulationProgram structure, which gives a little more control over the visualization
	"""
	program.simulate = True
	vis.setPlugin(program)
	vis.show()
	while vis.shown():
		time.sleep(0.1)
	return
	"""
	
	#this code manually updates the visualization
	vis.add("world",world)
	vis.show()
	t0 = time.time()
	while vis.shown():
		vis.lock()
		sim.simulate(0.01)
		sim.updateWorld()
		vis.unlock()
		t1 = time.time()
		time.sleep(max(0.01-(t1-t0),0.001))
		t0 = t1
	return

sim.setController(robot,balls_controller.make(sim,hand,program.dt))

	#the next line latches the current configuration in the PID controller...
	sim.controller(0).setPIDCommand(robot.getConfig(),robot.getVelocity())

	"""
	#this code uses the GLSimulationProgram structure, which gives a little more control over the visualization
	vis.setPlugin(program)
	vis.show()
	while vis.shown():
		time.sleep(0.1)
	return
	"""

	#this code manually updates the visualization
	vis.add("world",world)
	vis.show()
	t0 = time.time()
	while vis.shown():
		vis.lock()
		sim.simulate(0.01)
		sim.updateWorld()
		vis.unlock()
		t1 = time.time()
		time.sleep(max(0.01-(t1-t0),0.001))
		t0 = t1
	return

import shelf_controller
	sim.setController(robot,shelf_controller.make(sim,hand,program.dt))

	#the next line latches the current configuration in the PID controller...
	sim.controller(0).setPIDCommand(robot.getConfig(),robot.getVelocity())
	
	#this code uses the GLSimulationProgram structure, which gives a little more control over the visualization
	vis.setPlugin(program)
	program.reshape(800,600)
	vis.show()
	while vis.shown():
		time.sleep(0.1)
	return
	
	#this code manually updates the vis
	vis.add("world",world)
	vis.show()
	t0 = time.time()
	while vis.shown():
		vis.lock()
		sim.simulate(0.01)
		sim.updateWorld()
		vis.unlock()
		t1 = time.time()
		time.sleep(max(0.01-(t1-t0),0.001))
		t0 = t1
	return