Update 3! This bit took some real fudging around... I've put the more stable altitude physics/lift spring on the original craft, and have also introduced power-based thrust, so the power of the thrusters for each direction determines the acceleration to the maximum self-powered velocity. This is both mouse-and-controller enabled. So on a keyboard your thrust power and top speed is always maximum, but on a controller you can vary it. So we currently have Forward/Aft movement and strafing, and altogether.
You can also get a quick upward boost by hitting the 'E' key, which I forgot to demo in this video. I did however make the spotlights on the front toggle-able with the 'L' key, which I did demonstrate
So, here's all the currently exposed variables to tweak the physics:
VelocForward
< Maximum Possible Self-Powered Forward Velocity.
VelocReverse
< Maximum Possible Self-Powered Reverse Velocity.
AccelThrust
< Forward Thruster Power.
AccelBrake
< Reverse Thruster Power.
AccelDrag
< How fast it stops once hands are off the controls, (all inputs are 0).
StrafeSpeed
< Maximum Strafing Velocity.
StrafeThrust
< Strafe Thruster Power.
AccelJump
< Additional lift-Spring power applied when 'E' key is pressed.
CraftAltitude
< Hover-Altitude of the craft.
Lift Spring
< Power of the altitude 'spring'. Think of this as spring stiffness.
Lift Damp
< Damping Factor (Friction) of the lift spring.
http://www.youtube.com/watch?v=cdhDASEehaE
In the video I've added a few functions to keep the craft facing the same direction for now. Though, I think I have a better understanding of Spring Physics now, which I guess is what BZ2 simulates for its hover altitudes... thanks to this:
http://www.myphysicslab.com/spring1.html