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.
--
Lennart Gr?nlund
http://www.pip.dknet.dk/~pip2351/
