Disable look up/down effect on directional speed

Hi, I’m trying to get a FPS camera going, which is easy to set up using Babylon JS.
However, I would like to disable the effect of panning the camera has on the base forward / left / right / back directions.

For example:


If you look straight down and press the up arrow, you won’t move. If you press the back arrow and look down, you start to gain altitude. If you jump, look down and press the back arrow, you will slow the falling speed and eventually go up.

Is there an easy way to make the arrow keys always move the cam in the pressed direction with the same speed, regardless of the up/down angle of the camera?