>On Tue, 23 Jul 1996 15:49:03 -0500, "Imre Olajos, Jr."
>>Yesterday I was committed to squeeze the best possible frame rate out of GP2
>>and I have experimented a lot with it. I used to have the slowdown during
>>accidents and at times when smoke appeared on my P133, but now it's GONE!
>>Here's the little "trick" I found to work all the time: in the graphics
>>option menu set the target frame rate to something 2.0 (or more) lower than
>>the projected (calculated) frame rate.
>>For example, on my machine with most SVGA textures on, no mirror textures and
>>all objects drawn the projected (calculated) frame rate that GP2 gives me is
>>17.0. If I set my target frame rate to 17.0, I will see the usual slowdown/
>>crawling machine effects. However, if I set the target frame rate to 15.0
>>(without changing anything else), there are no slowdowns and the game handles
>>much better (smoother graphics, more responsive) !!!
>>I have no idea why this is so, but it does work for me. Try it out and let me
>>my P133/32MB EDO RAM/Matrox w/ 4MB WRAM machine has a processor occupancy of
>>100-110% on Hockenheim, and it looks darn good!)
>I think the explanation goes like this:
>25fps means each frame is displayed 1/25sec. = 0.04sec. on the screen.
>15fps means each frame is displayed 1/15sec = 0.07sec. on the screen.
>An arbitrary frame takes for example 0.06 seconds to calculate on your
>computer. Therefore with 25fps the computer has to slow down because
>you only reserved 0.04sec. to calculate and display that frame. But
>with 15fps your computer has 0.07sec. to do the job, and therefore it
>can relax for a whole 0.01sec.
>So with a lower framerate you are simply reserving more time to
>calculate and display each frame, and therefore you will not
>experiences so many SLOWDOWNS in the game. (In the sense of
>playability/gameplay I suppose this is a sort of "smoothness")
>But you are not getting more SMOOTHNESS (in terms of the following
>definition) with a lower framerate - an example:
>You are travelling with 83 meters/second (about 300 km/h). Observe a
>sign on the trackside:
>1) with 25fps (which was equal to 0.04sec/frame):
>then between 2 frames, the sign has moved 0.04 x 83 = 3.3 meters.
>2) with 15fps (which was equal to 0.07sec/frame):
>then between 2 frames, the sign has moved 0.07 x 83 = 5.8 meters.
>In other words, the sign is not drawn in so many frames with a low
>framerate as with a high framerate, and therefore is the movement not
>as smooth.
>However, 15fps can look smooth - for instance many cartoons are drawn
>with only 12fps and still looks smooth, but not as smooth as Disney's
>25fps though.
>That's it, in my view anyway - do correct me if i'm wrong or unclear
>on something.
What you say does sound correct although I am not sure if your 2) is
right, I think it might be the case that game still only moves the sign
3.3 metres at 15fps. If I am right and my logic is correct, then a lap at
25fps with a constant 100% occupancy would take less real time than
a lap at 15fps with a constant occupancy of 100%
The reason I suspect this is because at 15fps the game seems to take
longer to travel the same distance than at 25fps (from my eyes anyway)
and consequently for GP1 and GP2 to give a better perception of speed
one needs higher framerates. The upside is that you aren't really missing
anything (visually) and can control your car better at lower framerates
with respect to traffic. It was generally accepted that with GP1 the game
would have finer control at 25fps over 15fps because it would process your
input more.
With Papyrus Sims you appear to travel the same distance independant of
framerate, with the bonus of higher framerates being smoother graphics.
So I think your 1) and 2) would be correct for their sims.
Now with respect to GP2 and 15fps appearing smoother, I agree with
you fully. I think we could say its more a case of travelling a distance
at a constant speed than a fast/slow/fast as is seen at 25fps and > 100%
rather than a "blink less" Papyrus type smoothness.
Assuming I am correct about GP2 and it using 3.3 for both 25 and 15;
If the occupancy is often above 100% GP2 might draw 25 frames in 1 sec,
then it might take 2 secs to draw 25 frames. The result is that you have
travelled 83 metres in 1 sec, then 83 metres in 2 secs e.g 55 metres per
second then 28 metres the next. At 15fps you have only travelled 49.5
metres in 1 sec, but you will travel at this speed every second.
Then of course we could also talk about scale, I don't think Geoff
Crammond has the scale correct. If a sign is 3 car lengths long, then
the sign should travel past in the same proportion to your car. Take a
look at the ESSO signs at SAN MARINO to see what I mean.
Now for the standard disclaimer, I really love GP1 and now GP2
and think they are great and recommend people buy GP2. I overlook
their failings and have loads of fun playing them.
So there you have my views too, I am open minded and if you or anyone has
a different view lets hear them, after all this is a group for discussion.
Regards,
David Greene
>--
>Lennart Gr?nlund
>http://www.pip.dknet.dk/~pip2351/
