The Framerate Debate

[FarCry]

I have seen this topic come up a number of times on the forums and the mods always end up locking it because the argument is old, played out and stupid. People have gotten so pissy over the framerate issue that, now, if you even bring it up it seems to be grounds for locking a thread.

 

There are 2 schools of thought on this topic. One group thinks that a game (or the hardware that game is on) MUST produce 60+ frames per second or it's a huge pile of sheet. The other group thinks that as long as the frame rate meets or exceeds that which is necessary to provide the illusion of buttery smooth motion, then it's good enough.

 

I'm here to clarify a few things because I believe that the former of those 2 feel the way they do because they are misinformed and unaware of the way the framerate situation works.

 

Without getting into a long discussion about Flicker Fusion Frequencies, after-images, etc...The framerate issue breaks down like this.

 

All humans perceive light differently and all humans have a slightly different threshold at which an animated image appears to move smoothly. On average, however, this threshold tends to hover between 15 and 17 images (frames) per second. (Please not that I am NOT talking about light flicker - I am talking, VERY SPECIFICALLY, about continuous movement in animation. Flicker is a TOTALLY different subject and has more to do with refresh rates)

 

If the number of images per second drops below an individual person's threshold, they will notice "chop" or stuttering in the animation. If the number of images per second is above an individual person's threshold, the animation will appear smooth and continuous.

 

In NTSC television (America / Canada) images on the screen are produced by scanning every other line, 60 times per second. Lines 1, 3, 5, 7, 9, etc.. are drawn on one pass and then 2, 4, 6, 8, 10, etc.. on the next. This is called "interlaced scan(ning)" and is the "I" in 480I and 1080I. So since it takes 2 passes, at 60 passes per second (60Hz refresh rate) to draw each image, we get 30 images (frames) per second (It's actually 29.97 FPS but that can only be explained via a long technical dissertation that I haven't the desire to present, right now). Standard televisions are not able to exceed this limitation.

 

In PAL television (Western Europe and most of the rest of the World, not including eastern Europe, France and some countries in Africa which use "SECAM" images are also produced in an interlaced scan but at 50Hz...hence they are presented at 25 images (frames) per second. Here, too, most televisions are not able to exceed that limitation.

 

In motion pictures (like you see in the theater) all movies run at a standard 24 images (frames) per second. There is NO overcoming this, at this time. standard movie cameras run at this speed so that's what we see on the screen.

 

When is the last time you saw a television show or a movie in the theater that was choppy? I'll answer for you...NEVER.

 

So why is it that people have these great big fits when a game's frame rate drops below 60? (and GOD FORBID they get down to 30...it's a friggin federal case at that point!)

 

It's simply because they don't understand human physiology. Yes, our eyes can see in hundreds of frames (images) per second...But when we're looking at something that falls below the number of frames our eyes can see, our brain interpolates the images and makes assumptions, then fills in the gaps. In essence, we hallucinate the bits that we can't see. It's the same reason that every human being has a blind spot, but you'll never know unless you look for it. Your brain takes all of the available information and then fills in the blank spots with what it believes should be there...Tricky, isn't it?

 

Now, the next time you see that a game has a frame rate of 30 FPS, think back on this and ask yourself..."When is the last time that I saw a choppy movie on TV or in the theater". If you can't come up with an honest answer to that question then don't give it a second thought.

 

http://base.teamxbox.com/blog-post/tag/Terraphon/555/11-11-2006/p1/

 

Afterimage Separation

 

My biggest complain is with games that sacrifice too much frame rate for detail and I don't like any game if its too choppy. There is no exact number since its different for each game.

 

I can agree with this. There are some games that sacrifice in the name of graphics. Generally, however, what you're seeing is called afterimage separation. That's what happens when things move a little TOO fast and your brain doesn't fill in the gaps between what it saw and what it's seeing, properly.

 

Usually, things like that can be fixed with multisampling, motion blur, etc. If you look at GoW, you'll see a VERY fine example of the latter being used very well to smooth things out and minimize afterimage separation.

[JohnDio]

Η ημιμάθεια είναι χειρότερη από την αμάθεια. Αυτό να πεις στους φωστήρες του Teambox που ξύπνησαν μια μέρα και έμαθαν από framerate. Πάρε άρθρο και δώσε βάση,υπάρχει από το 2001......ασχέτως που μερικοί έχετε μείνει στην καραμέλα των 25fps των ταινιών

 

http://amo.net/NT/02-21-01FPS.html

 

Even if you could put motion blur into games, it would be a waste. The Human Eye perceives information continuously, we do not perceive the world through frames. You could say we perceive the external visual world through streams, and only lose it when our eyes blink. In games, an implemented motion blur would cause the game to behave erratically; the programming wouldn't be as precise. An example would be playing a game like Unreal Tournament, if there was motion blur used, there would be problems calculating the exact position of an object (another player), so it would be really tough to hit something with your weapon. With motion blur in a game, the object in question would not really exist in any of the places where the "blur" is positioned, that is the object wouldn't exist at exactly coordiante XYZ. With exact frames, those without blur, each pixel, each object is exactly where it should be in the set space and time.

 

Και επειδή πολλοί μιλάτε αδικώς για το Motion Blur:

 

Motion Blur is so important in movies and TV programming

In my first article, I mentioned how important motion blur is pertaining to frames per second. On Computers, this is essentially non-existant. Motion blur in movies, which run at 24 frames per second are designed for the big screen projector, which blasts movies to the screen, each frame in it's entirety in the widescreen format one frame at a time. Because each frame is filmed in a certain way, motion blur is used, meaning the frames are not perfectly clear, they contain blur.

 

The blur used in todays movies will eventually be replaced by completely digital movies (on very expensive screens, I should know, I worked with the technology at age 16), and with the advent of computer animation in movies, the process of replacing the blur on the film in movies is becoming more and more inevitable.

 

Computer's don't work this way (with blur that is), and essentially neither does anything digital. With digital, you either have an exact perfectly clear image, or an exact perfectly blur image like in movies. From the transition from movies to the TV, or DVD digital, an extra 4 frames are added each second in a method called frame mixing, just to match correctly the device it's being displayed on, your TV. NTSC(American) and PAL(european) use different kinds of TV formats, each with different refresh rates and resolutions. 640x480 for NTSC and 800x600 lines for PAL. With HDTV, everything is digital, and essentially 60 frames now, but most of these broadcasts use frame mixing, and until 2006 you won't need to trash your regular TV, though it may be a good idea now.

 

As many of you know, pause a DVD film movie during movement, or if you can a TV with your VCR and you'll see the blur (unless the image is static to begin with). Pause an animation DVD, or a cartoon on TV and you won't see the blur. Why is this so? Filmed movies, and Filmed TV shows work by bluring their subjects, actors, actresses, whatever. Filmed movies and TV are not taking a PERFECT snapshot image of the subject, each image is a blur, and a blur to the next giving the impression that everything is moving seemlessly (if nothing is moving in the scene, you can see a static image). In an animation or a cartoon, each frame or image of the 24/30 frames per second is perfect, there is no blur in the image - EVER.

 

I touched very breifly on AutoFocus Cameras, and even the best most expensive cameras not even coming close to matching the capabilities of our human eye in focusing. The professional cameras you see reporters with are capable of taking pictures of EXTREMELY fast moving objects in perfectly still quality at and above 1/4000 of a second. What does a camera being able to take 4000 pictures in a second prove?

 

Το site εξηγεί πως λειτουργεί το ανθρώπινο μάτι και όλες τις διαφορές που υπάρχουν στον μύθο των 30 καρέ το δευτερόλεπτο (το οποίο ΛΑΝΘΑΣΜΕΝΑ χρησιμοποιούν μερικοί που το έχουν ακούσει και στα videogames). Και ναι δεν είμαι ούτε εγώ υπεράνρθωπος που είπες FarCry,ούτε όλοι οι άλλοι. Απλά εσύ προφανώς δεν έχεις παίξει ποτέ ένα παιχνίδι με constant 60 καρέ το δευτερόλεπτο για να δεις τι σημαίνει smooth gaming. Και δεν χρειάζομαι και FRAPS για να καταλάβω πότε πέφτει το framerate. Αυτά

 

PS: Επίσης άλλο η πραγματική blurred εικόνα που λαμβάνεις από τον πραγματικό κόσμο κι άλλο η εικόνα των games στην οποία έχει προστεθεί blur effect στα frames. Το ανθρώπινο μάτι δεν λαμβάνει την εικόνα με frames. Όταν καταλάβετε πως γίνεται rendering μια σκήνη και πως βλέπετε τότε ίσως καταλάβετε ότι χρειάζονται παραπάνω από 30 καρέ για ομαλή κίνηση.

PS2: Κι όσο για τα 25 καρέ στις ταινίες..........έχεις δει τηλεοράσεις που υποστηρίζουν 100Hz ή παραπάνω και στις οποίες τα DVD's δείχνουν πιο αληθινά,σαν να μην έχει γίνει μοντάζ; Κοίτα να δεις που παρατηρείς ακόμα και στις ταινίες διαφορά

PS3: Ναι ο john2 είμαι κι έχω φάει ban,δεν χρειαζόταν να κάνω νέο account για μια βδομάδα αλλά ΕΛΕΟΣ με την παραπληροφόρηση σε 3 threads.

 

 

Edit:

 

http://en.wikipedia.org/wiki/Frame_rate#Frame_rates_in_video_games (ή μήπως δεν εμπιστεύεστε τώρα ξαφνικά και το wikipedia; Λέω εγώ τώρα)

 

Frame rates are considered important in video games. The frame rate can make the difference between a game that is playable and one that is not. The first 3D first-person adventure game for a personal computer, 3D Monster Maze, had a frame rate of approximately 6 fps, and was still a success, being playable and addictive. In modern action-oriented games where players must visually track animated objects and react quickly, frame rates of approximately 50 to 60 fps are considered minimally acceptable, though this can vary significantly from game to game.

 

It should also be noted that there is a rather large controversy over what is known as the "feel" of the game frame rate. It is argued that games with extremely high frame rates "feel" better and smoother than those that are just getting by. This is especially true in games such as a first-person shooter. There is often a noticeable choppiness perceived in most computer rendered video, despite it being above the flicker fusion frequency.

 

This choppiness is not a perceived flicker, but a perceived gap between the object in motion and its afterimage left in the eye from the last frame. A computer samples one point in time, then nothing is sampled until the next frame is rendered, so a visible gap can be seen between the moving object and its afterimage in the eye. Many driving games have this problem, like NASCAR 2005: Chase for the Cup for Xbox, and Gran Turismo 4. The polygon count in a frame may be too much to keep the game running smoothly for a second. The processing power needs to go to the polygon count and usually takes away the power from the framerate.

 

The reason computer rendered video has a noticeable afterimage separation problem and camera captured video does not is that a camera shutter interrupts the light two or three times for every film frame, thus exposing the film to 2 or 3 samples at different points in time. The light can also enter for the entire time the shutter is open, thus exposing the film to a continuous sample over this time. These multiple samples are naturally interpolated together on the same frame. This leads to a small amount of motion blur between one frame and the next which allows them to smoothly transition.

 

An example of afterimage separation can be seen when taking a quick 180 degree turn in a game in only 1 second. A still object in the game would render 60 times evenly on that 180 degree arc (at 60 Hz frame rate), and visibly this would separate the object and its afterimage by 3 degrees. A small object and its afterimage 3 degrees apart are quite noticeably separated on screen.

 

The solution to this problem would be to interpolate the extra frames together in the back-buffer (field multisampling), or simulate the motion blur seen by the human eye in the rendering engine (με απλά λόγια να μην γίνεται ότι και σήμερα,δηλαδή δημιουργία frame->blur effect->δημιουργία νέου frame. Μιλάμε για κάτι που θα ξεσκίσει όλες τις game engines κι όχι για ένα απλό εφέ που μπορείς να το αφαιρείς από τα Game Options). When vertical sync is enabled, video cards only output a maximum frame rate equal to the refresh rate of the monitor. All extra frames are dropped. When vertical sync is disabled, the video card is free to render frames as fast as it can, but the display of those rendered frames is still limited to the refresh rate of the monitor. For example, a card may render a game at 100 FPS on a monitor running 75 Hz refresh, but no more than 75 FPS can actually be displayed on screen.

[FarCry]

Ego agapite milisa GENIKA. de kathomai na paro tis eidikes periptoseis.

 

In modern action-oriented games where players must visually track animated objects and react quickly, frame rates of approximately 50 to 60 fps are considered minimally acceptable

 

Katarxin to arthro pou parethesa kala ta leei an to prosekseis.

 

1) leei oti to mati blepei ekatontades frames

 

Yes, our eyes can see in hundreds of frames (images) per second...But when we're looking at something that falls below the number of frames our eyes can see, our brain interpolates the images and makes assumptions, then fills in the gaps

 

Ipothesi

 

1) Ok esto oti to mati katalabainei 200 frames ok?

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

 

Gia na exoume 0 interpolation theloume 200 frames. Kato tou 200 o egkefalos kanei interpolation opos kanoun kai oi TFT ton 6-bits kai bgazoun apo 18-bit xroma 16.2M.

 

Osa perissotera kare exeis => perissoteri pliroforia apo to mati => ligotero interpolation => omalotero gaming => kalitero accuracy

 

Fisika gia games low speed den exeis profano kerdos. Auto pigainei sta FPS kai sta simulation

 

Oxi omos kanei stuttering kai einai unplayable. ELEOS

 

Allo na einai ligotero smooth kai allo to stuttering

 

Apo to video tis 3DFX to leei ksekathara

 

3Dfx's 60Hz/30Hz/15Hz demo

 

It's pretty simple: you get twice as many frames (or images)

with a game running at 60hz than you do with a game

running at 30Hz So, your eyes getting more images, your brain doesn't have to resort to doing as much interpolation (leading to bluriness) as it has to in the 30Hz case.

 

In pratice:

-----------

Sure, 30Hz is already a pretty good frame rate and most games

and 3D applications are quite usable at this rate.

 

At 60Hz however, the additional images provides both a more

comfortable visual experience and a better reactivity to

what's going on the screen: more images allows for better

interpolation and more accurate prediction of where a moving

object is going to be

 

To opoio einai eksidikeumeni PERIPTOSI TOU KANONA (de paizoun oloi FPS gia onoma tou theou)

 

Auta apo emena. To arthro pou parethesa sosta ta leei ektos apo auto to kommati

 

So why is it that people have these great big fits when a game's frame rate drops below 60? (and GOD FORBID they get down to 30...it's a friggin federal case at that point!)

 

It's simply because they don't understand human physiology

 

Parenthesi

 

De simferei sta FPS na baloun blurring gia na meiosoun tis apaitiseis ton frames enanti tou smoothness dioti meioneis tin katharotita tou stoxou kai diskoleueis ti stoxeusi

[EKTELESTES]

Ρε κόψτε τις μαμακίες και σοβαρευτείτε.

 

Κάνετε κ τα λινκ που πόσταρα πριν επικόλληση, αλήτρες

 

Τέρμα η συζήτηση, τα πράγματα είναι απλά.

[FarCry]

Ρε κόψτε τις μαμακίες και σοβαρευτείτε.

 

Κάνετε κ τα λινκ που πόσταρα πριν επικόλληση, αλήτρες

 

Τέρμα η συζήτηση, τα πράγματα είναι απλά.

 

Video 25 fps xoris blur effect aplos gia na deite.

 

http://www.100fps.com/nomotionblur.avi

[JohnDio]

Εγώ πάντως δεν είπα ποτέ ότι είναι Unplayable στα 30 καρέ ένα παιχνίδι,απλά δεν τρέχει τέλεια είπα. Χαρακτηριστικά είχα πει ότι όταν πέφτει στα 38 το framerate στο Colin: Dirt το παρατηρούσα ότι "έσπαγε" λίγο η κίνηση (κι εσύ με έβγαλες αμέσως υπεράνθρωπο. I luv being Superman ). Άσε δε που μπέρδευες στην αρχή τα 25-30 καρέ των ταινιών με τα παιχνίδια .

 

Εν κατακλείδι,δεν κατηγορώ όποιον δεν διακρίνει εύκολα την διαφορά,όπως έχω ξαναπεί έχω ευαίσθητα μάτια και καλώς ή κακώς παρατηρώ διάφορα πράγματα πιο εύκολα. Το ιδανικό ΓΙΑ ΜΕΝΑ είναι να τρέχει ένα παιχνίδι με 45fps και πάνω. Όταν πέφτει στα 30 μου κάνει μπαμ εμένα που έχω συνηθήσει τόσο καιρό να παίζω στα 50+ constant fps (εξαίρεση αποτελούν παιχνίδια που η κάμερα δεν κινείται πολύ γρήγορα αλλά τόσο στο Colin: Dirt,όσο και στα C&C3 και Spiderman3,που τα 2 τελευταία είναι και 30fps capped,η κάμερα κινείται σχετικά γρήγορα και παρατηρείται η διαφορά). Το μάτι μπορεί να δει εκατομμύρια fps,δεν υπάρχει όριο αλλά το "τέλειο" είναι το 60άρι χωρίς πτώσεις προς τα κάτω. Σαφώς και ένα παιχνίδι είναι playable στα 30,απλά ΕΜΕΝΑ δεν με καλύπτει να τρέχει ένα παιχνίδι με τόσα γιατί το βλέπω ότι σπάει η κίνηση και θέλω να τρέχει κομπλέ,ούτως ώστε να γουστάρω ΕΓΩ κι όχι για να λέω ότι το τάδε παιχνίδι τρέχει με τόσα fps .

 

PS: Τα λέμε από την επόμενη βδομάδα όταν και βγει το ban. Μέχρι τότε take care

PS2: Στο video που έδωσες παρατηρώ ότι τα δέντρα (μετά την θάλασσα δηλαδή και ειδικά όταν εμφανίζεται κάτι σαν φράχτης) δεν κινούνται τέλεια. Το ίδιο ισχύει και στα πολύ κοντινά αντικείμενα που περνάνε γρήγορα,υπάρχει το μικρό κόψιμο δηλαδή και το παρατήρησα

[FarCry]

Εγώ πάντως δεν είπα ποτέ ότι είναι Unplayable στα 30 καρέ ένα παιχνίδι,απλά δεν τρέχει τέλεια είπα.

 

Lathos autos edo to eipe. BARESTE TON. EPITHESI :twisted:

aplos mou ti barese otan to diabasa

 

Αρχικό μήνυμα απο isaias1983

Analoga ti enoei o kathenas playable...egw pantws otan peftei katw apo 45fps den to thewrw playable

 

kala entaksei esi sto Crysis na se do pou tha klais

 

Άσε δε που μπέρδευες στην αρχή τα 25-30 καρέ των ταινιών με τα παιχνίδια .

 

to blur effect stin tileorasi de to eixa proseksei giauto. fainetai apo ta 3-3.5 metra me mia tileorasi 21''? 20'' effective. tin epomeni fora tha dokimaso na to entopiso

 

PS: kala to video einai kai 25 fps. esi paratireis kopsimo sta 40! . Ego pali de blepo kopsimo. Aplos i metabasi den einai toso smooth logo tis eleipsis tou blur

PPS: prepei na stamatiseis gia 1 xrono ta games giati se ligo tha theleis 100 frames oxi 45

[isaias1983]

file mou an katseis k diavaseis grafw oti egw den to thewrw playable...einai stin apopsi k tin gnwmi tou kathenos to ti thewrei playable..twra ean esi paizeis me 15-25 fps k goustareis einai diko sou thema!gia MENA proswpika ta 15-25 fps einai san na paizw se slow motion...panta milaw gia to colin mcrae dirt gia na min parexigithw..exw paixei k paixnidia pou exoun max 30 fps k paizw mia xara!px. to teleutaio pou thimamai einai to resident evil 4 pou kollaei sta 30 fps alla to game paizei mia xara!