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Framerates Matter
An anonymous reader writes "As more and more games move away from 60fps, the myth of the human eye only being able to detect 30fps keeps popping up. What's more, most people don't seem to realize the numerous advantages of a high framerate, and there's plenty of those."
The article notes about motion blurring, and links to NVidia's page about it's technology. The last figure shows a terrain with full-screen motion blur effect, which in my opinion is pretty important in games to create that feeling of speed. People usually object against this and bloom effects and just want a sharp picture, but maybe some games have taken it too far. It's important none the less, even if it's not all sharp picture, because your eye picture isn't all that sharp either and you experience the same blur.
Not sure how much it matters to sales, though.
she's dead, Jim
Looks like it's Slashdotted already. Here's the cached page: http://74.125.47.132/search?hl=en&q=cache%3Awww.significant-bits.com%2Fframerates-do-matter&aq=f&oq=&aqi=
HOWEVER
The human mind is evolutionary designed to make instant assumptions. Cat in mid air facing us = DANGER. No "Is it dead and being thrown at us?" No "Is it a picture?" As such, video games can quite easily take advantage of this evolutionary assumptions and trick the MIND, if not the brain. into thinking something is real.
So while a higher frame rate will increase the quality of the game, it is not essential. It's like getting gold plated controls on your car's dashboard. Yes it is a real increase in quality, but most people would rather spend the money on a GPS device, real leather, plug-in-hybrid engines before you get around to putting gold in the car.
excitingthingstodo.blogspot.com
I couldn't agree more. That Internal Server Error looks way better at 120 Hz on my 45" HD display.
"Until the become conscious they will never rebel, and until after they have rebelled they cannot become conscious"
I thought I was super badass at street fighter 2 in middle school, then I went to the arcade and saw older kids getting the insane combos on killer instinct. First thing I thought was... wow, you really have to study this stuff to know what you're doing. If only there was some sort of global information network where I could quickly and easily find out what all those moves are.
You can tell the difference between 30 FPS and 60 FPS.
The way I tested this was I made a 2 second video in flash, a circle moving from the left side of the screen to the right side. 60 frames. Run it at 30 FPS.
Then I made a second 2 second video, same exact positions. 12 Frames. Ran it at 60 FPS. Asked me, and all of my surrounding classmates, which was about 24 students IIRC.
100% of us noticed a visible difference in the smoothness. Whether our eyes were making out each individual frame perfectly or blurring some together to create a smoother effect, it was irrelevant since there WAS a noticable difference. I was going to slowly bump the 30 and 60 FPS up higher and higher to see at what point the difference is not distinguishable, but I got lazy (High school student at the time.)
The point I think most gamers would agree on is that more frames per second are nice - but that 30 frames per second are Necessary. You can occaisonally dip down to 24 and be alright (24 is supposedly the speed that most Movie theatres play at) - but when you get around 20 or so its really does take away from the experience.
That isn't always the case, I recall a game in the past where gravity had less effect on players that had faster hardware. Or something like that. Anyway, the logic was mixed in with the rendering, so frame rate had an impact on what the player could do.
Nerd rage is the funniest rage.
15 FPS vs 30 FPS vs 60 FPS. This is a visual representation. There are points made, however, that when you watch a movie, the image is "softened" and runs at a lower framerate [something like 24 or 25 FPS?] because your brain helps "fill in the gaps" or something of that sort. Pretty interesting stuff.
Hmm... I don't accept that premise, either on the PC (where midrange graphics cards can easily pull 60fps with any game on the market now) or on the consoles (where framerates are only going up as PS3 and 360 development matures).
I think that this article (or at least the summary) is a bit of a strawman. Most of the gamers I know recognize that good framerates are important.
It's way, way way more than that.
The old HL engine -- at least in Natural Selection, but most likely any game on that engine -- your framerate didn't just effect your gravity (which made it so that at certain framerates you could literally jump further, which meant BHopping was sicker)..
it also changed the DPS of weapons. Yep. Weapon firing rate was tied to FPS in a very very odd way. Some dudes did too much testing. Insane.
And you can, visually, tell a difference between 100fps and 50fps and 25fps. Very easily. Takes a few minutes of playing, but there's a clear difference and anybody saying otherwise eats paint chips.
Graphics don't make games good. Graphics can cripple good games. Graphics never make bad games good.
... still waiting for this free-as-in-beer free beer I keep hearing about.
Everyone says a "framerate" (i.e., sample frequency) of 44.1kHz is all that is needed. Yet many people hear better imaging, depth and transparency at higher sample rates.
I've worked with the Doom source code recently, and can confirm that there was no motion blur at all. In fact, blur of any kind couldn't really be implemented, because Doom's graphics were 8-bit indexed colour.
Also, there were no engine changes at all between Doom 1 and 2.
Perhaps the GP is referring to the bobbing effect that occurs when the Doom guy runs. That moves the camera nearer to and away from the ground, changing the appearance of the texture.
You're an immobile computer, remember?
The 30-fps-is-all-you-can-see myth was probably born of the notion that the illusion of continuous movement starts to set in around 25-30fps (in film for example). Therefore actually 30fps is the minimum you need rather than the maximum you can perceive.
I think it's more likely born of the notion that film gives a completely convincing illusion of motion that is not greatly improved by higher frame rates, because the process by which it is created automatically includes motion blur because it's recording continuous data, just broken up into 24 fps. Computer games display discreet moments in time, not many moments blurred together into one picture. That's why film looks smoother than computer games with 3 times the framerate.
Nevertheless, the illusion of continuous movement is apparent at much lower framerates than even film, even in a computer game. Quake's models were animated at 10 fps, and they gave a convincing illusion of movement, and you can probably make due with a lot less since the brain fills in so much. But it's not a completely convincing illusion, and neither is 30, 60, or even 100 when using static instants in time.
But the basic myth comes from the fact that film is so convincing and thus you don't "need" more... as long as each frame is a blurred representation of the full period of time it is displayed for.
The enemies of Democracy are
I am a visual neuroscientist (IAAVNS). The standard idea of refresh rate comes from CRT based monitors where the image is drawn by a scanning electron beam. If you use an instrument to measure the instantaneous brightness at a given point on the screen it will rapidly peak as the beam swings by, and then decay as the phosphor continues to release absorbed energy in the form of photons. Different monitors have different decay rates, and, typically, CRTs that were designed for television use have pretty slow decay rates. CRTs that were designed for computer monitors typically have faster decay rates. If the decay rate were very very fast, then the hypothetical point on the screen would be dark most of the time and only occasionally very bright as the beam sweeps by on each frame.
As you can imagine this highly impulsive temporal profile is hard to smooth out into something closer to the constant brightness of the world around us. The human retina has an inherent dynamic response rate to it, but it's actually quite fast, and there have been studies showing clear responses in higher order visual areas of the brain up to 135 Hz. But standard phosphors used in CRTs have a little smoother response, and so at more-or-less 80 Hz, the brain stops seeing the flicker (at 60 Hz most people see flicker on a computer monitor). The exact refresh rate where perceptual blurring happens (so the flickering goes away) varies widely between individual, and with the exact details of the environment and what is being shown on the screen. More-or-less at 100 Hz refresh, no one sees the flicker anymore (although the brain can be shown to be still responding).
Contemporary screens, however, are LCD based (I'm going to ignore plasma screens since the field is still working out how they interact with the visual system). Making the same experiment as above, the temporal profile of brightness at a given spot on the screen will look more like a staircase, holding a value until the next frame gets drawn. This is a far, far smoother stimulus for the visual system, so a 60 Hz frame rate produces a perceptually far more flicker-free experience. That's why most CRTs at 60 Hz make your eyes bleed, while LCDs at 60 Hz are just fine.
Except that newer LCDs have LED backlighting which is no longer constant, but flashed (WHY? WHY? WHY? Just to save some power? Please, computer manufacturers, let *me* make that decision!), so the experience is somewhat more like a CRT.
So that's one part of the equation: flicker.
The other part of the equation is update rate, which still applies even there might be no flicker at all. Here, we have the evidence that the brain is responding at up to 135 Hz. In measurements made in my lab, I've found some responses up to 160 Hz. But the brain is super good at interpolating static images and deducing the motion. This is called "apparent motion" and is why strings of lights illuminated in sequence seem to move around a theater marquis. The brain is really good at that. Which is why even a 24 Hz movie (with 48 Hz frame doubling) in a movie theater is perceptually acceptable, but a 200 Hz movie would look much more like a window into reality. On TV you can see the difference between shows that have been shot on film (at 24 Hz) versus on video (at 30 or 60 Hz). Video seems clearer, less movie like.
For games, 60 Hz means 16 ms between frame updates -- and that can be a significant delay for twitch response. Further, modern LCD monitors have an inherent two or three frame processing delay, adding to the latency. As we know, long latency leads to poor gameplay. Faster updates means, potentially shorter latency, since it is a frame-by-frame issue.
So, just as with audio equipment where inexpensive low-fidelity equipment can produce an acceptable experience, while a more expensive setup can create the illusion of being at a concert, so too inexpensive video equipment (from camera to video board to monitor) can produce an acceptable experience, while a more expensive setup can create the illusion of visual reality.
Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.
more accurately - most film cameras don't have a notion of a shutter 'speed'.
The film roll still goes by at 24fps, but the actual shutter is a wheel. That wheel can have various sizes of gaps (to increase/decrease exposure *time*) and sizes (to produce specific motion blur effects; e.g. an object leading its own motion blur path requires a small shutter opening at first, ending in a large shutter opening). You use fairly sensitive film and a small shutter gap, and you'll get nearly motion blur-less shots like that of Saving Private Ryan (watch explosions in that film and every speck of dirt that gets thrown about appears almost razor-sharp; some find this objectionable). Heck, you can even expose twice per frame if you want to get all experimental and stuff.
That said.. you can't - short of electronic shutters - expose for -more- than the film's fps, though. A bit under 1/24th of a second is the most you'll get (that 'bit' being required to transport the film to the next frame).
Anyway.. wiki: http://en.wikipedia.org/wiki/Rotary_disc_shutter
I'm a neuroscientist that covers sensation and perception and its bidirectional interaction with cognition, particularly attention. I've got comments and questions and very few answers after reading this. I'm seeing a lot of things stated as facts that I've never heard of before. Some of them make sense, and some don't. Some of them are correct, some not, and many more than the others combined I have no experience in and can't say. Those seem to be well supported, or at least well known, particularly among those who've obviously done their homework. I can find references to these among the publications (like ACM) that are most applicable to the field in question, but I can find precious little in my customary pubs and books. That's not to say the stuff in the technically oriented pubs is wrong, just that some may not be covered much (ie. 'not of interest') in my field. My field is very cautious about experimental evidence, but I suspect in gaming's perception area there are common knowledge kids of things that came from hear say (we have many of those in rocketry too). It might do well for both fields to compare works.
What catches my eye at first is this "myth". As stated it's overly simplistic. Which humans' eye? Some have different reaction times. Those who could probably detect 30 fps discontinuity are those who see the TV screen jiggle and waver when they chew something crunchy while watching (you know who you are, here's a place to own up to it). What part of the visual field, central or peripheral? They operate differently. Jittering or blurring of objects attended to or not? Betcha it happens more to those not attended to, but that's not noticed for the same reason (hypnosis can bring that out right nicely). And how is it frame rates matter when the visual system evolved as a constant flow analog system? If a phenomenon that shouldn't make a difference does, and that frame rate is strictly due to technical considerations, how do we know that a variable frame rate might not give even better results? Since the visual system does not have full-field frames that refresh, why should artificial presentations? Why not present faster moving objects at a high change rate, slower moving at a slower rate, more or less a timing equivalent to some video compression techniques? Some of this makes good sense from my perspective, some appears goofy but may not be, and some clearly is whack according to well supported experimental evidence from my side, not sure about yours.
Here's an interesting one, apparent motion from blurring, occurring at the retina, ostensibly due to 'reaction time' of light receptor cells (rods and cones). I can see how this might occur. But if it's a time lag that causes blurring, everything should be blurred, because the layers of cells of different types in the retina between the receptors and those firing down the optic nerve operate strictly by slow potentials -- there's not a 'firing' neuron among them. Or, if their processing, though slow, accounts for motion and compensates, preventing adding to the blurring, how can that be used to increase apparent motion?
A last point which I'm fairly certain isn't covered in gaming and graphics presentation because very few know much about it and we don't understand it well: 10% of the optic nerve is feed-forward, top down control or tuning of the retina and its processing. Motion perception can be primed, can suffer from habituation, and has variance in efficacy according to several factors. What cognitive factors have an influence on this, and how can that be used to improve motion perception and/or produce motion perception that's as adequate as what's being used now but requiring less external computational effort because internal computation is being stimulated.
It's probable that both fields have things of interest and use to the other, including things the other isn't aware of. I've said much the same following another article on a different subject. From this one I can see it's probable there's a few peoples' careers worth o
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
The human eye can detect FAR MORE than 30FPS.
And here's a simple way to prove it - find yourself some 60Hz fluorescent lighting. Look up into the light, wave your hand in front of it. Note the strobe effects, and if you're good enough you can count the different hand images and do some math to figure out your eyes average response time/FPS. Do the same thing in front of an incandescent light bulbs, notice you don't get a blur.
The average calculated human response is approximately 72 FPS.
You also 'predict the future' as it takes about 1/10 of a second for the signal from your eyes to be processed by the brain. When you play baseball and make a swing, your brain is automatically doing lots of lag compensation so you can actually hit such a fast moving object.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
But why? Motion blur is overrated. Sure put it in scenes where it is "important to the story/gameplay", but to use it whenever there is fast motion is stupid.
:).
Why? Because people aren't staring at the same spot on the screen all the time. And nowadays screens are getting bigger.
Say in real life, you're in a room where there are two moving objects that are moving around at fast but eye-trackable speeds in different directions.
If you are staring at sommething else, both objects are blurry.
But if you start to look at one, that particular object becomes _sharp_, the other object becomes blurry.
You look at the other, it becomes sharp and the other becomes blurry.
When a game or movie blurs moving stuff, it just makes stuff you are looking at look out of focus even if they are moving at speeds which your eye can track. You can't focus on it even if in real life you could!
With motion blur, I often experience eye strain when I try to track moving objects/backgrounds that have been blurred.
Then there are the artificial "out of focus" shots in static scenes. These effects should also be restricted to scenes where it is important to the story that only a few items are in focus.
In Avatar (2D), my eyes were often trying to focus on blurry images and it wasn't pleasant - initially I was wondering what was wrong with my eyes - felt like I had difficulty focusing on stuff.
When I watched it in 3D, I realized that a lot of stuff was actually blurry and it wasn't my eyes. In some fairly static scenes the focal range was low - only a few objects were in focus. Then in some scenes the moving objects were blurry. Whereas in other scenes most stuff was in focus. In Avatar 3D it was easier to figure out where I "should" be looking and avoid the eyestrain bits
If you ask me I prefer as much of each frame to be sharp and in focus as possible, then let the limitations of my eyes blur it.
Artificial blurring (motion or defocus) is like listening to artificially degraded music/audio. While there are some cases that call for it (distance effect) it's just silly if you use it a lot.