Re: [FT] Sensor Range Question

On Tue, 27 Apr 1999, Oerjan Ohlson wrote:

> Thomas Anderson wrote:
> 
> > > 'Course, if you assume f = 1 you need more complicated vector
> > > movement rules to stay realistic <G>
> > 
> > i think it's fairly simple to fix the rules though; it's just a pain
> 
> It is quite simple. If the thruster pushes go on throughout the entire
> turn the ship ends up exactly half-way between the "coasting end
point"
> and the point where the FTFB Vector rules would put it, but the new
> movement vector is calculated between the starting point and the point
> FTFB specifies.

aah, right, i was thinking of fixing cinematic, for some reason. this
would involve applying your acceleration twice - once to get the speed
to
use this turn and one for next turn.

looking at what you wrote, i see what you meant. yes, that would be
better; in fact, when i tried to write my own vector rules, that's how
they worked. since i haven't seen FB's vector rules, i have been
assuming
they worked like mine. evidently they don't.

> No more to keep track of than now, but it takes a bit
> longer to execute each move.

in my system, you need to do:

- call ship position P
- plot initial velocity vector from P; call the end Q
- plot acceleration vector from Q; call the end R
- measure a vector from P to R; this is the new velocity vector
- place the ship halfway between Q and R, facing R

this assumes a ship turns instantly, points in one direction the whole
time and burns for the whole turn.

i don't know how it's done in FB; i assume the last step is replaced by
"place the ship at R, facing in the direction Q>R".

anyway, it's not a great addition.

> Of course this "half-distance move" is slightly off if the ship has to
> spend time turning, but with 15-minute turns the time required to turn
> the ship around should be small enough that the error is <<1 mu. I
> usually can't move my ships with half-mm precision :-7

i tried to figure out how it should work if the ship turns over the
course
of the turns, but the maths rapidly develops a bad case of trigonometry
which i can't cure :-).

the thing about instant turns is that it follows that all ships should
be
allowed unlimited turning (at the start of the move), which isn't
terribly
good for gameplay.

Tom