Librelancer 2022.02

Is there any way to rotate camera in the system view? I just see controls to move around.
And unfortunately when clicking on Gameplay Demo, the music of Liberty starts, but the game is stuck in a loop. No errors, only “no sur found” warnings.

Edit: When moving around in LI01 the game also gets stuck when approaching Fort Bush or getting Manhatten in my view.

When I try to switch systems, it crashes.
Would be nice to remember the freelancer install location between runs.
Awesome proof of concept though.

Well, the physics in Freelancer are a lot like flying an airplane rather than a ship in space.
That means that every force has a counter force and that’s why you stop if you turn off your engine (not engine kill!).
So the standard physic equations for speed, distance and acceleration, etc. apply to FL.

I’ve added some info regarding engines and thrusters to the wiki, so head over if you got any questions. I’ll write something on ship handling in the next weeks.

Your work on this is unbelievable. You deserve much more fanfare. I don’t think I’ve ever even seen THN files decoded and re-rendered like that before.

Starship flight physics in Freelancer is pretty much Newtonian (barring rounding errors and of course the fact that masses don’t attract each other as they would in reality). The reason you stop when you throttle down is linear drag (compare to Stokes’ friction) and hardly a good model for atmospheric flight, really.
Anyway, when you kill your engine, the engine’s drag is not taken into account any longer, and so the only thing (literally) “dragging” you down anymore is your ship’s linear drag which tends to be rather small by comparison (in vanilla it’s 599 on the engine and 1 on the ship, if memory serves).
So if x( t ) is your location at time t, m your total mass, b( t ) your raw thrust force (be it from engine, or thruster, or indeed any other accelerating influence, like explosions can be, or the sum of any of the above) as a function of time t, v0 your velocity at t = 0, and d your linear drag (be it from engine, or ship, or the sum of both), then your velocity v( t ) as a function of time t is given as
v( t ) = v0 + ( b( t ) * t - d * x( t ) ) / m ,
<=> dx(t) / dt + d / m * x( t ) = v0 + b( t ) / m * t .
This is an inhomogenous linear first order differential equation with constant coefficients. An implementation of this sort of mechanics of course doesn’t require understanding the theory behind forms like these. Suffice it to say that our b is bounded (there is, after all, a maximum thrust for any accelerator in the game, and only a finite amount of them can be effective at once because computers have finite memory) and if we keep it constant at any value, then in the long run our speed approaches the familiar old thrust/drag ratio c = b / d as I will demonstrate now, along with what I mean by “the long run” and how it is a matter of the ratio j = d / m of drag and mass:
Assuming that your thrust b is constant, and that we start at the location x0 = 0, the exact analytic solution x( t ) to our motion equation is
x( t ) = c * t + ( c - v0 ) * ( exp( -j * t ) - 1 ) / j .Already we see j both scaling how far x deviates from a linear expression, as well as how quickly that linear expression is reapproached. x is also shifted by something proportional to the difference of thrust/drag and starting velocity. Let’s see how velocity behaves:
v( t ) = dx(t) / dt = c - ( c - v0 ) * exp( -j * t ) .
We could see it before, but now it’s a lot more obvious: At t = 0 our velocity is exactly v0. As t gets very big, the latter term vanishes almost completely, effectively only leaving behind The promised thrust/drag. We also see that j scales how quickly the latter term vanishes even more clearly now. We can now choose a speed w between v0 and c but not equal to c, and find out how long it takes for our ship’s speed to pass by it as it keeps approaching
t( w ) = ( log( c - v0 ) - log( c - w ) ) / j ,where ‘log’ denotes the natural logarithm.

Now, of course, there are rounding errors due to the discretion of values inherent in digital computing systems. Not even space in vanilla Freelancer is truly continuous which is why we see our ship jitter ever more as we move further away from the system’s center. The formalism I presented is an idealized, mathematical, analytical model, and as we measure the actual motion we are bound to find slight errors and imprecisions, but this is, as far as I know, how Freelancer’s physics are at least supposed to behave.