Re: [TuxKart-users] Is this a bug?

[Steve B. <sjb...@ai...>]

La Temperanza wrote:

> Anyway, I've been wondering why the CPU, quite frequently, goes 
> careening from wall  to wall with rather suspicious precision at speeds 
> in excess of 90MPH- I can never go faster then about 65 unless using a 
> magnet on one of them. This behavior is easy to observe in Geeko Peak.


There is a bug (which is annoyingly hard to fix) relating to what happens
when one part of the track crosses another.  Sometimes, the computer
controlled players start crossing a bridge and suddenly come to believe
that they are in fact on the part of the course running under the bridge.
At this point they try to follow the centerline of the road beneath the
bridge - generally resulting in a violent crash against the sides of the
track.  Having crashed, they may then decide they are back on the bridge
section again...this activity can repeat over and over until they sometimes
hit the wall with enough speed to actually pop through it and end up
beneath the track or something.

This is hard to fix because the track centerline data that tells the other
karts where to go - and which has some other functions too - is only two-dimensional
so a kart close to the intersection of two segments *can* get confused.

As for the excessive speed, there is a dirty secret going on in TuxKart
(as with many computer racing games) which is that to make the game a
little more exciting, the cars in front of you slow down a little - so
you stand a chance of catching them - and the cars behind you speed
up a little to give them a chance of catching you.

This may sound bad - but without it, car driving games are BORING because
one teeny tiny mistake on your part puts you behind  the pack with no
way to catch up again - and if you were just 1% better at driving a
GoKart than the computer, you'd never see another computer player in
front of you.  Keeping lots of other cars bunched up around you
keeps the game interesting.

When the computer-controlled karts get confused because of the 'bridge'
problem, they suddenly think they are *WAY* behind you and speed up
accordingly.  Of course ordinarily, you wouldn't see them do this and
it wouldn't be noticable - but when they do it in plain sight - it's a
bit obvious!  So, if the centerline thing was fixed, this wouldn't be
a problem.

I have not been working on TuxKart for almost two years now - but I am
working on a Water-Skiing game ("TuxWave") that requires the same trick
for figuring out where the boat goes.  I fully intend to come up with a
better scheme for that game - and when I have it working, I'll put it back
into TuxKart.

----------------------------- Steve Baker -------------------------------
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