Originally posted by Benny Moore
How is the aircraft mass handled in Aces High II? I know from the screenshots in the stall speed thread that lift and drag are intricately modelled, having many points being calculated in real time. Is mass done the same way? If so, is the weight evenly distributed along the points, or is the majority of it in the fuselage and less in the wingtips?
Actually the calculation is not real time, but uses pre-calcualted tables for the aerodynamics. Real time, high accuracy calculation is not possible on todays computers. From what I understand, what is calcualted are the sum of forces each element of the model give.
As for mass: For every element (wing section, attached bomb, fuel tank etc) you only need 3 things:
Its mass, its inertia moment (per axis) and position. From this you can get the total mass, the center of mass and total inertia moment in each axis.
That, in fact, was exactly what I had in mind when I asked the original question. I was flying my P-38 and someone asked me what I thought about the inertia modelling. He wondered why the rolling always stopped as soon as you let go of the stick. My initial response was that I thought it's fine, but after thinking about it and trying it out, we discussed it some more. I recall roll inertia being an especially big problem on the P-38 and P-61, because the engines were away from the center of gravity.
The problem with inertia was for initiating the roll. P-38 could reach high roll rate but it took time to build, giving a long delay between stick deflection and the actuall roll motion. This seems to be modeled in the game.
When you center the stick there already is a strong roll moment in the opposite direction. This is because the rising wing has now a lower angle of attack (less lift) then the lowered one (while the roll motion is mainteded). It would slow the roll quite fast - how fast? I'm not sure, but in the game (as far as I remember) the "over roll" is negligible. It would be interesting to see how external wing bombs/rockets/DT affect the roll rate and inertia if anyone cares to test this.
Generally, I'm a bit suspecious of the control responses in AH, especially the elevator. I suspect they are too sharp, especially at slow speeds. I don't think that the jink motions we can do near stall are that realistic. Perhaps the stick deflection is linked directly to the wing AoA instead of the elevator's AoA that governs the main wing's. I don't know.
Improving flight models but making them simple and fast enough to run on a home computer is quite a challange I suspect. Some compromises are have to be made and not everything can be modeled directly. A relevant example migh tbe the high speed roll rate. In RL it was limited by the force the pilot's arm could apply on the stick. Our flimsy, plastic joystick can be deflected in a split second. The result is that the actual roll is not directly related to the stick deflection, but slightly delayed. So is the stiffening of the elevator at high speeds.
So far AH gives the best compromise and it keeps improving. We have seen quite a few FM improvements over the last few years. I hope more will come.
