Algodoo

sorry for lack of coloring but it is a nice system
numpad 8 to retract port
WASDQE for control
[ ' for clamp control,
] \ for hatch control

Docking procedure:
place port in other port,
close clamps,
retract port,
open hatch.

springs can be used to move capsule away from station or whatever...
you can use these im your scene with crediting!