每秒帧数指1秒时间内的平均播放帧数。假如你获得的帧率为60fps，并不能表明你在这一秒时间中的某些阶段看到这些帧。你可能刚开始看到10帧，随后画面暂停50毫秒，然后在剩余时间内看到另外50帧，那么帧率依然是60fps。当你每毫秒看到1帧时，帧率同样是60fps。结果是什么呢？在前一个例子中，你可能看到的是“停顿”的画面，而第二个例子中你可以看到流畅播放的视频，而这两者的帧率都是60fps。如果你想知道更多有关这个话题的信息，可以阅读Scott Wasson在The Tech Report上发表的文章《Inside the second》。
The Illusion of Fluidity and the Evil FPS God
I was discussing a possible upgrade solution for a friend a few days ago and he was adamant about getting an extremely costly upgrade, despite my best intentions. He mentioned he wanted to get “over 100 fps” in games and when i asked why, he just answered “to play games fluently”. And this seems to be a recurring theme in today’s hardware wars.
Let’s discuss the ubiquitous FPS term first. Frames per second, colloquially known as FPS, is a measurement of how many frames can a video card provide per second while rendering a given virtual environment, a raw representation of processing power. This has become an industry standard, along with games like Crysis and Metro 2033 and benchmarking tools like 3dMark, for illustrating the processing capabilities of video cards. It’s a common occurrence to say “i get 50 fps with Crysis 2 on Ultra”, and this is generally and inherently considered better than getting 40fps with a weaker video card on the same game with the same settings.
While the bulk of the idea is correct, you should get a better overall experience with the better card, it’s very far away from being completely true.
FPS relies on the perceived notion that we, as gamers, care about FPS. We don’t care about FPS as a concept, we care about having our games look good and play good. FPS seems to have attached itself like a parasite to the issues of game fluidity and wrongly so.
Let’s delve into that shall we?
Frames per second indicate the average of frames over a second. If say you get 60 frames per second, there’s no telling where in that second you got those frames. You could get 10 frames at start then pause for 50 milliseconds and then get another 50 frames, and you still have 60 frames per second. 60 frames per second you will also have when you get a frame every millisecond. The result? The first example you will experience as a “stutter”, while the second one you will experience as a smooth flow of video, both having the same ubiquitous 60 FPS. If you care to know more about this particular subject, read the great article by Scott Wasson at The Tech Report called “Inside the second” since we’ll diverge in a moment.
Going further, saying you get 50 frames per second average in a game might mean you get 40-60 frames per second at any moment in the game but it might also mean you get 100 frames per second 50% of the time with 50% drops to 5 frames per second. Again, i know i’m exaggerating, but only to make clear what i’m trying to say:
FPS is a raw measurement of processing power from a pure engineering point of view. While it can produce a somewhat correct expectation what our experience will be, it is only related to that one second or a particular scene and it isn’t and shouldn’t be a go-to figure for the whole experience.
Let’s draw it back a second. Movies and television run at 24 or 30 frames per second and you don’t see people complaining about low FPS in those mediums. You could say they are not interactive, but then again, it doesn’t matter. We’re discussing the illusion of motion and the experience of flow.
We’ve all been to Youtube at one time or another and had a video of something we were watching and enjoying start to stutter or stop completely. We then sighed and either dropped the quality of the video or waited for it to load a bit more. Our experience is then stained, especially if that happens at a point where you’re invested into the video, like a great movie or video game trailer.
The same thing happens in video games as well. While we most likely won’t notice the difference between 60 and 80 frames per second, it’s the 15 frame per second drop that we notice and that makes us consider “i should get an upgrade”.
RAGE came out not long ago and used a new engine called idTech 5. While initially it was rather buggy visually, the concept was great. It involved on the fly texture up and downscaling among other things, to provide for a smoother experience. The video quality adjusted according to how well your computer could run it and that’s without messing around with a dozen settings to tweak and done purely automatic by the game.
What was the conclusion? The game ran smoothly.
The point i’m trying to make is that the goal for everyone involved in the gaming industry, including the clients, come to the realization that, like the film industry, we need to adhere to a standard that preserves the illusion of fluidity.
Consoles have beaten us to the punch on that with their standardized configuration, and while that has done wonders and keeps making consoles an ‘easy’ way to get into gaming without hassle, the visual quality suffered, as can be seen with all the limitations in today’s console games.
Let’s go wild a bit.
Instead of FPS, let’s have an IFR, an Illusion of Fluidity Rating based on a generalized ideal of each frame-return of 25 milliseconds, as in, 40 frames per second. For the sake of the discussion, we’ll not go into Vsync and screen tearing although it appears Nvidia is working on a great technology called Adaptive Vsync which will solve this issue.
Returning to the matter at hand, video card performance will be listed in IFR standards. More powerful graphics cards would have a better Illusion of Fluidity Rating with more visually-demanding games, while even less powerful cards could play all the indie/less demanding games with maximum 100% IFR, as in, a smooth 25 milliseconds frame time or a minimum of 40 frames per second at any given moment in the game.
So a modern video card can say on its box, instead of “gets 9800 points in Haven”, “gives 90% IFR in Haven benchmark”, which would mean that for 90% of the benchmark, the card will offer a smooth rendition, with 10% of the frames having a longer processing time, thus, averaged, a lower FPS.
The goal in the end is to switch the focus from the engineering FPS term to the fact that actually concerns us as gamers, smooth gameplay. While i’m sure there will still be enthusiasts that upgrade and overclock their PC’s and brag with high FPS numbers, they actually care about the hardware and software capabilities and it’s an engineering endeavor as much worth pursuing as tuning your car or your musical instrument. I merely wish we wouldn’t have to always have that be a pressing concern in order to enjoy our games.
Sadly, it seems both consumers, hardware companies and even developers shy away from an experience-driven method of doing things to a pure engineering way which might impress people in the know, but it does nothing to help me or you enjoy our experience within a game.
I hope, for the sake of a better game and the renegation of such worries that detract from a pleasant gaming experience and hobby enjoyment, that we will finally move away from the FPS God and embrace a new, healthy, mentality that will benefit all of the gaming industry. (Source: Gamasutra)