You can set the
reference frame of the crosshair to viz.RF_VIEW:
Code:
crosshair = viz.addTexQuad(texture=viz.add('crosshair.png'),pos=[0,0,3],scale=[0.5]*3)
crosshair.setReferenceFrame(viz.RF_VIEW)
I'll post a simple example soon that uses the pick command to track the objects looked at.