rec.autos.simulators

You'll definitely notice a difference... Once your system can maintain
30+fps all the time, your consistency will go up dramatically.

Trips

now now ... no need to be silly!!  :-)

Think about GP2, and how smooth it is at 25.4 fps.  The problem with
GPL is exactly that the frame rate fluctuates wildly if you are
under 36 fps.  I think they should have a slider for selecting a
max frame rate lower than 36 fps.  Having a frame rate pegged at
30 fps would be much better than fluctuating from 30 to 36.  Heck
24 fps used to seem fast in ICR2.  I hope N2K will allow some lower
max frame rate.

--
Pat Dotson
IMPACT Motorsports
http://www.impactmotorsports.com/pd.html

% >
% > While one can compensate for slower frame rates, IMO this is a handicap.
% > What I find more important than a fast frame rate, is a "steady" frame
% > rate.  However, if the frame rate runs below 36 fps in GPL, there is a
% > high tendency for the frame rate to flucuate.  When the frame rate is
% > below the optimum, the screen updates the car and track in a jerky

% Think about GP2, and how smooth it is at 25.4 fps.  The problem with
% GPL is exactly that the frame rate fluctuates wildly if you are
% under 36 fps.  I think they should have a slider for selecting a
% max frame rate lower than 36 fps.  Having a frame rate pegged at
% 30 fps would be much better than fluctuating from 30 to 36.  Heck
% 24 fps used to seem fast in ICR2.  I hope N2K will allow some lower
% max frame rate.

While the frame rate may be smooth and constant in GP2, GP2 expanded and
collapsed time to achieve this.  This also had an affect on how one
controlled the car.  Papy may want to consider going back it's tried and
proven method of automatically reducting detail levels to achieve a
fairly constant frame rate.  However, this process also robs CPU cycles
and this may be why it wasn't included in GPL (which is alreay CPU
extensive).

--
**************************** Michael E. Carver *************************
     Upside out, or inside down...False alarm the only game in town.

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=<[ /./.  [-  < ]>=-=-=-=-=-=-=-=-=-=-=-=-=-=

The only problem with GP2 is that it slows down the entire game to compensate
for lower frame rates.  This is much more annoying to me than a slight change
in the frame rate.  30fps is very playable, even if it has dropped from 36.

Ryan Kocher
The Leader of the Free World

I think Pat's argument was more along the line that GP2 looks great
with constant 25 fps, and doesn't need 36 fps to look good. If I
understood this correctly, I agree. Crammonds logic "if the game is
set to 25 frames per second, one second in-game time will be as long
as it takes to draw 25 frames - even if this takes three real seconds"
is flawed. But once in-game time and real time are synchronized
properly, the sim looks good with 25 fps and is very playable.

Actually, GP2 and GPL are very similar in one point, even though the
one takes the "slomo" approach and the other the "leave out frames"
approach: both GPL and GP2 are playable only if you have set the sim
in a way that your processor isn't fully occupied all the time. In
GP2, one would adjust details to get considerably less than 100%
"processor occupancy" in average. In GPL, IMO, you have to make sure
that the framerate is almost always at 36 fps. Otherwise, the sim will
not be enjoyable.

Once the program is fluctuating between 25 and 36 fps, my timing will
be as much messed up as when GP2 went into slow motion on my old P90.
I think (but I'm not sure) that a "rev limiter" which allowed to
preselect the max. framerate would help this a lot.

I agree. I used this feature mainly to find out what fps my system is
capable of, and then set features to "on" or "off", rather than
"auto". Grandstands emptying and filling up in fractions of seconds is
a bit distracting, too.

--
Wolfgang Preiss   \ E-mail copies of replies to this posting are welcome.

Of course it does, but that's irrelevant to my point :)

Regardless of time warp, the frame rate seems totally smooth.
I think that's due to the fact that FR is _pegged_ at 25.4,
and doesn't change at all.  In effect, Papy does the same
thing as long as frame rate stays above 36 - it stays
constant.  Thankfully, they didn't use the ludicrous
time expansion of GP2 if FR drops below 36.

What is needed is other settings for that constant upper
limit of frame rate currently fixed at 36.  Options for
20, 24, 26, and 30 fps would allow slower computers to
still maintain a constant max frame rate.

I think my proposal is better than changing the detail
level becuase is doesn't rob cpu cycles.  Without having
tested this theory, the idea of acheiving a lower
constant frame rate seems like the best compromise for
lower powered computers.

--
------------------------------------------------------

IMPACT Motorsports
http://www.impactmotorsports.com/pd.html
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Yes, it sucks big time.  I've been as critical of this
scheme as anyone.  The perception of smoothness in GP2
is hard to beat, though.

My argument is that if you have a computer that can't
maintain a constant 36 fps, it may be more preferable
for the user to have the option of changing the max
frame rate from 36 to 30, rather than having the frame
rate vary between 30 and 36.

In fact, based on my perception of GP2 at 25.4, I wouldn't
be surprised if GPL at 25.4 fps would be better than GPL
fluctuating between 30 and 36.

What I am getting at is that the human eye may be very
sensitive to fluctuating frame rates - and that a lower
constant frame rate may be better than a higher fluctuating
frame rate.  Is anyone aware of any study into this topic?

--
------------------------------------------------------

IMPACT Motorsports
http://www.impactmotorsports.com/pd.html
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Yes yes yes.  Thanks for getting it.

Yep, it's very noticeable when GPL isn't maxed out at 36 fps.

That's exactly what I meant.  I think an adjustable "rev limiter",
as you call it, should help a lot.  Not only from a visual standpoint,
but also for racing online, where you need to be able to maintain
the max frame rate for a good connection.

--
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IMPACT Motorsports
http://www.impactmotorsports.com/pd.html
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Lots of work on this general topic in the commercial/military aircraft
simulator world.  Another place to look might be the National Advanced
Driver Simulator (NADS, I kid you not) -- a big project (USD ~40M, our tax
money at work) funded by the US Government, located in Iowa.  They have
generated a lot of proposals and papers, but seem to be having trouble
getting online...

I don't have any references handy, sorry.  Maybe someone with some time
could do a net search?

-- Doug

                Milliken Research Associates Inc.