Space Engineers PIP indicator for PMW (torpedoes).
Predicted interception point indicator shows the point of torpedo impact. PMW stands for player-made weapons.
PIP has the advantage of being on-target, so you can adjust aim manually to hit specific zone of the target.
PIP mode can be also used to shoot without lock, by "zeroing" the distance manually and following a target with crosshair, giving the code possibility to infer target speed and make firing solution. It's not very accurate, but gives at least a hind on how much you have to lead your shots for current weapon in the absence of lock.
The Draugr drone used for testing is an automatic gravity-driven ship designed to give large slow capital vessels a hard time. Instead of using gravity torpedoes equipped with artmass, it just propels blast door slugs with its' acceleration (around 100ms^2 front/back). Flying it manually with WASD is fun but less effective, as the code does it better.