[Darkmax]

I'm not exactly understand what you are referring but if you want to something disappear when the marker is not shown you have do something like this:

import viz
viz.go()

#Add ARToolkit extension
ar = viz.add('artoolkit.dle')

#Create camera using first available webcam
camera = ar.addWebCamera()

#Create matrix marker
marker = camera.addMatrixMarker(0,width=1000)

#Add avatar model and set state 1
avatar = viz.add('vcc_male.cfg')
avatar.state(1)

#Link avatar model to marker sensor
viz.link(marker,avatar)

#Method that update if the marker is visible
def updateVisible():
	if marker.getVisible():
		avatar.visible(viz.ON)
	else:
		avatar.visible(viz.OFF)

vizact.ontimer(0,updateVisible)

I hope is that what you need