rec.autos.simulators

If you remember back to GPL without the BW patch, you saw just 5 other cars,
4 ahead and 1 behind. For that you needed something like 13kbps down and
6kbps up connection bandwidth. Extrapolating that to 20cars makes 52kbps
down and 6kbps up... that's more 33.6kbps and yet those 20 cars are in my
replay and look pretty smooth too. It would appear to me, in order to make
this work position data would have to be transferred less frequently, to the
detriment of position accuracy. There is a hint this may be happening at the
start of a race: while stationary behind the pacecar, the number of cars
shown is still fixed... it's only when they start to move others pop into
view.

So the question is this: has there been a software breakthrough that allows
more cars to be shown for less data or is there really a cars visible /
position accuracy trade-off? -If so, does it affect all cars equally or does
the update rate on cars close to me remain the same, with those further a
field getting updated less frequently?

Perhaps one of the people at Papy, Project Wildfire or another code guru can
shed some light on this?

Thanks,

Jan.
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1 means that the game use packet size for online (internet) racing, 0 would
be for lan, and it use a different packet size and frequency and that is the
reason why when you use 0 that you see more cars. But it sucks alots of
bandwitdh per client. But on the server side there is a way to force any
client to use the same frequency and packet size, thus reducing server
bandwitdh usage.

for your dial up and numbers of car i ain't to sure. Maybe the game will
only show a minimal amout of cars in front of you (while racing). But the
data for other cars are still received and recorded to your replay. Assuming
you are looking at a client replay and not the server one :-). But even me
with a cable connection i have lots of cars blackout when i'm looking at my
replay. So i presume if you can see that much cars (assuming they are real
drivers and not AI, that you probably have that configue line at 0. but i
may be wrong.

i'd like to give you a good answer but it has been a while since i raced
with dial up.

Eric Leblanc
Project Wildfire Beta Team.

Yes... bandwidth settings are 3/116 3/116, which, "in GPL terms", would only
suppport 6 or 7 cars if memory serves me right (can't get at Bart Westra's
page for some reason at the moment).

Yes I would imagine sierra.com forces bandwidth in the same way VROC does.

No... if I limit the view settings the cars which are not close enough to be
included are not in the replay either.

Gimme some credit here... <g>

Like I said... when everyone's lined up down pitlane the number of cars
shown is consistent with the bandwidth settings. Once people start moving
the field fills up to the number of cars according to my front/rear view
settings. They are there, both "live" and in the client replay. I used to
have it set to 16 in front, 5 behind, making 21 cars. Recently, this caused
framerate and skew problems with some servers, so I turned it down.

Reading between the lines you seem to agree this is not in alignment with
"known" technology. If a gametick still 1/36th of a second, are we to assume
that I got position updates on 21 cars every 3 gameticks (about 0.08s) or
just 7 each 3 gameticks, so every individual car only got updated every 9
gameticks (about 0.25s) with some sofisticated client side interpollation
thrown in for good measure?

0.25s is a *LONG* time at 195mph and provides ample opportunity for
individual games to get out of sync. If that's the case it's something, we,
as racers, should have been told about, IMO.

I have a cable connection at my disposal too and I used to think there was
some kind of negotiation which allowed for more bandwidth to be exchanged if
both the client and the server were up to it. It's when I found myself
forced to switch back to dial up due to stability issues on the cable
connection that I was amazed to see the same number of cars. It would appear
now both "media" use the same settings.

NRx also acts differently to GPL on upstream connection issues (as I've been
having on the cable connection). In GPL when you wink out due to an upstream
issue, all other cars dissapear on the client side. In NRx, if your
downstream is ok, you continue to see the other cars unless the problem is
extreme (winking out for 5 seconds or more). But that's a whole other issue.

Thanks for your response,

Jan.
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