in real space mass altars the light in the system you already have something in it that can simulate this the projected lines of where a body may go
iv seen loads of effects in games eg mass effect where you throw a singularity at the enemy and it sucks every 1 in but the other effects eg whats behind the effect gets warped and distorted around it .. it would be awesome if at a later date add something like that into your engine have a star in the background or the background itself get warped around a black hole
its known as gravitational lensing but would add a great feature in a possible later update