rec.autos.simulators

frame rates in general

Rob Jenki

frame rates in general

by Rob Jenki » Mon, 22 Feb 1999 04:00:00

Hi,
just wondering what is considered a smooth frame rate for driving games. it is
for an article I am writing, am I correct in saying that 24 frames per second
is the minimum we should have for film like smoothness?

thanks

rob

Drake Christens

frame rates in general

by Drake Christens » Mon, 22 Feb 1999 04:00:00



There is no single answer.  Some people are happy with 15 FPS.  Others
find 25 barely adequate.  And if you're racing against one or more
humans, the the person with the highest frame rate generally has a
distinct advantage.

And it's a little apples and oranges to compare any video frame rate to
film.  The mechanisms are so different that you can't make a one-to-one
comparison.

The 24 fps for film and 30 fps for video are probably somewhere in the
90% range of where people perceive the images as "smooth."  Maybe high
90's.

Mighty

David Mast

frame rates in general

by David Mast » Mon, 22 Feb 1999 04:00:00

Hate to waste bandwidth, but...

Good answer!!

David Mocn

frame rates in general

by David Mocn » Tue, 23 Feb 1999 04:00:00

I disagree. 24 fps is way too low to have a perfectly smooth experience. If
people tell you that you cannot tell the difference above 24fps then just try
it out yourself ... I have no problem telling the difference between 24, 30 or
60 fps.
Common misconception is the saying then your eyes will perceive 24 fps as
seamless. It is not quiete right ... at 24fps you cannot pick out single
frames but that doesn't make it perfectly smooth. BTW, movies use motion blur
(it is a natural "phenomenom" which games do nor replicate) and that is why
they look perfecly smooth. Without motion blur (ie. in games) it is a totally
different ball game. It depends on 2 things, your FPS as well as the size of
your screen/monitor. Think about it ... if you have something at 20 fps on a
watch size screen then it will apear smooth (bacause each frame will "move"
things my only tiny amounts (milimeters)). On the other hand, if you play
something at 20fps on a wall size screen (with no motion blur) then it is
quiete feasable that objects will jump literally meters from frame to frame
.. that is definatelly not smooth.
I find it that in computer games 60fps is flawless while 30fps is more than
adequatte though less then 30 seems to be flawed. I always require 30+ fps to
be "sumberged" in the experience.

Regards,
David Mocnay



>Hi,
>just wondering what is considered a smooth frame rate for driving games. it is
>for an article I am writing, am I correct in saying that 24 frames per second
>is the minimum we should have for film like smoothness?

>thanks

>rob

Peter Gag

frame rates in general

by Peter Gag » Wed, 24 Feb 1999 04:00:00





> > Hi,
> > just wondering what is considered a smooth frame rate for driving
> > games. it is for an article I am writing, am I correct in saying
> > that 24 frames per second is the minimum we should have for film
> > like smoothness?

> > thanks

> > rob

> There is no single answer.  Some people are happy with 15 FPS.  
> Others find 25 barely adequate.  And if you're racing against one
> or more humans, the the person with the highest frame rate
> generally has a distinct advantage.

> And it's a little apples and oranges to compare any video frame
> rate to film.  The mechanisms are so different that you can't make
> a one-to-one comparison.

> The 24 fps for film and 30 fps for video are probably somewhere in
> the 90% range of where people perceive the images as "smooth."  
> Maybe high 90's.

> Mighty

My understanding is that generally, the human eye can only percieve
differences in graphical images (tv, video, etc) up to around 30 - 32
fps?

However, higher frame rates in driving games/sims provide a smoother
view and can make the game/sim easier to drive even though the eye may
not notice any difference? This is because the game is being updated
faster, and control imputs are read more frequently, etc.

Two examples:

Formula 1 Grand Prix 2 (F1GP2) - from Microprose. The max fps
available is 25, and when run on a fast pc (with cpu occupancy mainly
below 100% - this is a whole other area we won't go into here!) it
runs and looks great at 25fps.

Grand Prix Legends (GPL) - From Sierra. The max fps is 36, and again
on a decent pc running at 36 is very smooth and adds to your ability
to control the car.

Thats a difference of 11 fps. Try running GPL at 25fps after running
it at 36 for a while, and there is a noticeable drop in performance.
Then again, I first ran GPL on an old k6 200 and *had* to turn off
most details and run it at around 25 fps and it was still *very*
playable and still looked great. So you could argue its all
subjective?

Some people seem very happy running thier games/sims at 20fps, maybe
cos they haven't had the equipment available to run them any faster?

I'de say the faster the better from a game/sim players point of view,
and an absolute minimum of.........?

Hmmmm tough one, acceptible levels are changing with technology too.

In F1GP2 nothing less than 25 would do? In GPL nothing less than 36
will do? In F1GP3 maybe only 50fps will do?

8-)

*Peter*   #:-)

Drake Christens

frame rates in general

by Drake Christens » Thu, 25 Feb 1999 04:00:00


says...
Nope.  30 fps is the minimum.  30 fps is where 90-odd% of people *stop
perceiving flicker* of an interlaced video signal.  Depending on the
content.  For example, your average movie or TV show.

OTOH, if you display fairly small text or thin horizontal lines at 30 fps
interlaced, most people perceive substantial flicker and get a headache
within just a few minutes.  A government group in Sweden set standards
for computer video signals that included a minimum of 72 Hz (AKA 72 fps)
refresh rate for just that reason.  Even at that refresh rate, some
people perceive flicker.

But more is not necessarily better.

In the late '70s or early '80s some group in Hollywood ran tests of high-
frame-rate film.  As they raised the frame rate, people reported that the
experience seemed much more realistic.  But, as they passed 70 fps they
found that the incidence of vertigo and nausea increased dramatically.  
Especially when showing content with lots of motion, like a roller
coaster.

US Air Force fighter pilots are also experiencing problems with nausea in
their newest high fidelity flight sims.  I'd be willing to wager that
several people on this newsgroup have suffered at least one bout of
vertigo while watching a friend play Wolf 3D/Doom/Quake.  There's a
fairly new medical term for this: Simulator Sickness.

As the frame rate increases and the visual and aural fidelity gets more
realistic the brain begins to get confused by conflicting signals.  The
information coming from the eyes and (in games) the ears are tell the
brain that the person is in motion.  But the inertial motion detectors of
the body (mostly the inner ear) tell the brain that the person is at
rest.  The brain throws up its psychic hands and says, "I give up."  AKA,
vertigo.

The highest fidelity sims in the world will always have this problem.  
Inertia is a basic physical property of your inner ear.  The only way
around it is if there's some way to stimulate the inner ear to match the
inertial forces it should be feeling.  Or to bypass it and feed the brain
the appropriate impulses.  Both appear quite a ways off.

Mighty

Larr

frame rates in general

by Larr » Sat, 06 Mar 1999 04:00:00

I think this is a great answer...

Sluggish performance tends to make you introduce too much steering input
because the game is always _behind_ you in reaction.

-Larry


> However, higher frame rates in driving games/sims provide a smoother
> view and can make the game/sim easier to drive even though the eye may
> not notice any difference? This is because the game is being updated
> faster, and control imputs are read more frequently, etc.


rec.autos.simulators is a usenet newsgroup formed in December, 1993. As this group was always unmoderated there may be some spam or off topic articles included. Some links do point back to racesimcentral.net as we could not validate the original address. Please report any pages that you believe warrant deletion from this archive (include the link in your email). RaceSimCentral.net is in no way responsible and does not endorse any of the content herein.