I know how to use the background system object extension. What I'm trying to do is make an effect where rotating spike walls cirle around a pole. When they're around front, they're in front of the pole, when they're in the back, they're behind it.
The problem is that whenever the screen scrolls, any moving background system object pastes itself into the background(in this case the bg system objects are the spikes when they're behind the pole).
Does anyone know a way around this?