Top Down Mouse Aiming

Hey guys I’m trying to make a Top Down Shooter but I’m very bad with vector maths so here is my issue :

I’m trying to make my projectiles go from the weapon muzzle to the mouse location, straight in line, and they must keep the same “altitude”, Z, all along ( no gravity ). So I don’t know how to fire both exactly at the same altitude (world space) and towards the mouse location ( screen space ).

Look here when Im firing, the bullets goes to the intersection between the mouse location and the ground, but if I add a Z to this location to match the character’s height, it will be off the cursor xD So yeah I’d really like some help on this please :slight_smile: