[farshizzo]

You can use a sub window to render an arbitrary scene on top of the main window. Here is an example script that shows how. Let me know if I misunderstood your question.

import viz
import vizact
viz.go()

# Render model to main window
viz.add('dojo.osgb')

# Create sub window
window = viz.addWindow()
window.clearcolor(viz.GRAY)

# Uncomment this line to have a transparent background
#window.setClearMask(viz.GL_COLOR_BUFFER_BIT,viz.MASK_REMOVE)

# Create view/scene for sub window
view = viz.addView()
scene = viz.addScene()
view.setScene(scene)
window.setView(view)
view.setPosition([0,0,-2])
view.lookAt([0,0,0])

# Add model to sub window
model = viz.add('beachball.osgb',scene=scene)
model.addAction(vizact.spin(0,1,0,90))