Gravity:
Type I - Non-dynamic gravity, constant pull from one direction, doesn't increase or decrease as you change your distance from the source direction
Type II - Object-based gravity, defined in pof data to give things like large asteroid pofs, gravitational attraction. Always pulls towards the object or objects flagged as having gravity, varies in strength over range. Strength and range figures are defined by the FREDder. If multiple objects have gravity, they will attract each other. Gravity may also be anchored to a point, rather than a pof file.
Lift:
A factor in a ships table entry will dictate its lift factors on ventral, dorsal and each side, which will act to partially counter gravity if the mission is flagged as being in a gravity and atmospheric environment. Lifting surfaces will also need to be in motion to generate lift, so the stall speed will be in the ships entry too. Also, the mission-dicated atmospheric density will have an effect on how much lift is being generated in that environment. The lift factor of a craft may be variable, for ships like the Thunderbolt from TBP (once it gets some animated sub-object capabilities) can be made to generate lift only when its wings are deployed.
Repulsion:
Additional lift factors based on thrusters, anti-grav, or whatever, will be in the tables, capable of thrusting in all directions, using standard axial thrust controls like for shivan ships. Some ships (Herc 1 for example) will have very poor lift, so while they may be used in an atmpshere, they will be limited in speed and maneuverability, also requiring the constant use of the axial thrust controls.
How's that?
