I guess my post wasn't that clear.

I'm trying to have a laser shoot from the ship's guns to the mouse, which is the aiming device. p.vel_x needs to be static, I think, because that would be the length of the laser.

The tracer I was talking about was simply an object I put in that always at the mouse position, 200 quants away from the camera. This was to ensure that it was a particle velocity confusion and not a problem with my mouse vec_for_screen code block.

My problem is that the laser does not shoot towards the mouse.