In my campaign, I would like to have a mission that occurs inside the accretion disk of a black hole, orbiting just above the event horizon, very close to the speed of light. Because motion in space is relative, all it should require is a fancy skybox and some FREDing.
Theoretically speaking, I think the event horizon (lower boundary) should be fairly easy: Fade the screen to black and end the mission if the player's Y coordinate drops below -2000
The upper boundary might be more complex though. Is there a way to stop the player from flying above 2000 Y? What is the best way to create a gravitational ceiling in FRED? Can FRED mimic gravity and pull stuff toward a coordinate, or along an axis? And if so, can this be used only on things above 2000 Y?
Using 'set-position' over and over again seems really wasteful and inefficient, like trying to kill a fly by ramming it with the Colossus.