This is in two dimensions. Repo with 3 dimension is here and initial testing was done on this private repl
Math for the simulation is from this paper by Radjaroendee, Jamraschai, and Hirunsirisawat
Preview is at https://bigspaceships.github.io/2D-Blackhole-Sim/
To control, click on blue to add a black hole, control click to delete a black hole, drag black holes to move them, and when moving them an option to change the mass will pop up on the right
Example:
