For swimming and noclipping.
Some joysticks have up to 6 axis, like 3D Connexion's 3dmice. It would be nice to use joyadvaxisz for vertical movement.
With the associated variables joyupsensitivity , joyupthreshold, and cl_upspeed.
Darkplaces source-port added this to the Quake1 engine, and Quake2 and Kingpin both have support for this out of the box.
Quake2 and Kingpin also activate jump and crouch when the vertical threshold is passed.
It would be fantastic if HexenII: Hammer of Thyrion could enable this feature as well! It would make playing much more enjoyable.
Thanks for your consideration!