Gun on creeen
Vector3f vectorDifference = new Vector3f(cam.getLocation().subtract(charPosition.getWorldTranslation()));
charPosition.setLocalTranslation(vectorDifference.addLocal(charPosition.getLocalTranslation()));
Quaternion worldDiff = new Quaternion(cam.getRotation().mult(charPosition.getWorldRotation().inverse()));
charPosition.setLocalRotation(worldDiff.multLocal(charPosition.getLocalRotation()));
// Move it to the bottom right of the screen
charPosition.move(cam.getDirection().mult(3));
charPosition.move(cam.getUp().mult(-0.8f));
charPosition.move(cam.getLeft().mult(-1f));
charPosition.rotate(0.3f, FastMath.PI, 0);