Good Stuff ! Stargate looks great.

If it's a polygonal looking tunnel you need. Try creating one panel (wall) in position with stargate at origin. Center its pivot point & duplicate it selecting the # of panels you'll need with a revolve (trial & error to get the fit most likely). You'll get a hexagon shape type tunnel or as many sides as you need. If your not at the origin of its opening you can animate this duplication to occure anywhere. Hope this is what you meant Bob