id Says 60fps Is Enough For Doom III

Dot.Com.CEO writes "IGN PC reports that the final version of Doom III will be capped at 60fps, quoting John Carmack as saying 'A fixed tic rate removes issues like Quake 3 had, where some jumps could only be made at certain framerates'. Will this put a stop to fans arguing whether there is a tangible benefit for frame rates over 60fps? What do Slashdot Games readers think about id's decision?" Elsewhere, there's a new preview of Doom III at C+VG, including a mini-interview with Carmack in which he comments: "Now's where it goes from being an interesting demonstration of all the technologies to being a fabulous game, and that really does all happen at the end."

Comments

Best Quote of the 2nd Article

[TheFlyingGoat]

Gotta love the sense of humor. :)

The first thing we realised was like: 'Damn, people are hard to kill in Doom 3 multiplayer. Why is that?' And we looked at the damage values, the hitpoints, the armour, but eventually we realised - we're just missing. We're lousy shots."

Before you get your panties in a bunch...

[Hellvetica]

From here: http://www.shacknews.com/ja.zz?id=8743907

Alright, I'm going to try and break this down... there are actually 3 entirely seperate things people are talking about here: simulation frame rate, rendering frame rate, and monitor refresh rate.

'Hurtz' or 'hz' are a universal term that just means "X whatevers per second", so having 60FPS means your card is rendering at 60hz.

Now, in the post Carmack says nothing about monitor refresh rate, so that really isn't anything to worry about. Your monitor will still refresh at whatever you want it to refresh at, within it's capabilities. The other two things, the simulation rate and the rendering rate are both going to be locked at 60hz/FPS.

Let me try an analogy. Let's say you are in a room, and next door there is a chess match. The frequency at which the chess pieces are moved is the simulation or game rate. Now if you have someone taking a polaroid snapshot at a certain rate, that is the rendering rate, what everyone knows as FPS. If someone else is taking those photographs and bringing them to you, that is like your monitors refresh rate.

This isn't a perfect analogy, but it's good enough to illustrate the point: if the chess pieces only move once per minute, no matter how often someone takes a picture of it, it will always look the same.

60hz is a big leap for the games simulation rate though, if i recall correctly quake 3 ran at around 20 to 25 by default, but you would see inbetween stuff due to a trick called interpolation. The statement in the article seems to imply that doom 3 won't be doing any interpolation, which I think is the most interesting aspect of the comment.

Re:Bad Idea

[PainKilleR-CE]

The problem really has nothing to do with how many frames the human eye can see in a second. As was almost implied by the previous reply, it has a lot more to do with your monitor's refresh rate at a given resolution. If your monitor is at 60hz, you're not getting more than 60fps whether your card puts it out or not, because the monitor isn't going to draw them (this is why v-sync is good for games, but is disabled for benchmarks, where the monitor shouldn't have any influence on the test).

Obviously, capping the framerate was the easiest way for id to solve this particular problem, and 60 fps is generally accepted as good enough. Anyone that thinks it isn't probably hasn't played many games capped at a certain framerate (for instance, you can cap your framerate in Half-Life and many other games). Once it's capped at a certain rate, it limits the possibility for severe slow-downs when framerates drop on complicated scenes. This is the real reason that having a card that plays 200 fps on the latest game (besides the obvious issues with previous Quake games) is important, because the higher average values mean higher values for the lowest framerate in a round. If you're playing with an average of 100 fps and the game slows to 60 fps, it's going to feel like it's crawling, but if you're playing at 60 fps and it drops to 50 fps you might have trouble even noticing it. If it never drops, even better ;)

In the end, at least they've done something to address a problem typical with their past engines. I wish they had found a more elegant solution that allowed individuals to choose higher framerates without affecting the gameplay, but something's better than nothing. The only people that will complain are the ones that spend most of their time staring at fps counters while they play or benchmarking their graphics cards with the latest demos. Maybe some people will finally figure out that their games would be more playable if they capped their framerates at a reasonable level rather than trying to buy faster hardware and tweaking their systems all day to acheive a 100fps average that gets slammed to 30 fps every time 5 people are on the screen at once.

In other words...

[stienman]

Translation:

Our engine is wicked fast because we calculate everything with integer math. Our physics engine runs at a rate fixed according to time, not machine cycles, so that any computer fast enough for the game will run the physics exactly the same as any other machine, and so integer math round-off errors will be consistant, and can be made up for in the map design.

We chose to fix the frame rate to the same rate as the physics engine so that video cards will not be re-rendering the same frame twice. If they did, then the game would appear jumpy.

If you run at 72fps, and the engine runs at 60, then you'd get a duplicate frame every 5 real frames. Since the controls are tied to the physics engine, the controls would feel laggy 12 times a second, until the frame rate again caught up with the engine.

The optimal setup will have the monitor set to 60Hz, or perhaps a higher frequency that is some multiple of 60Hz, but will result in quick beats: rather than 1 in 5, choose 90Hz so every third frame is a duplicate, or best choose 120Hz.

Or just turn off the flourescent lights. You want a terrifying experience anyway - who wants to play with the lights on?

-Adam

Not really a bad idea, (close)

[Ayanami Rei]

Here's the thing: The "refresh rate" of the human eye is about 15Hz. It's not really fair to call it a refresh rate since different parts of the eye transmit light level changes at different rates (faster in your periphial vision). It's just that on average, the cones and rods in your eyes take about 60ms to "settle".
Of course, the eye isn't taking snapshots, over this 60ms you're sort of summing the incoming light over the entire period, and transmitting the "average".

Thus, we see everything with motion blur pre-attached. Our brains and optical centers are wired to use that blurring to reconstruct the missing motion. Also used in the reconstruction: the fact that different parts of your eye can update independantly, so you have this distributed stream of information coming in whenever, and your brain is assimilating all of it and using all of it (including differences in timing) possible to get the best representation.

Okay, so then clearly, we need really high framerates because our eyes are not cameras telesynced to the monitor... we need to have the pixels as accurate as possible at every time because we never know when a cells in a region will want to transmit. We "figure out" that we are seeing stop frame animation, even if you saw the "snapshots" of the eye, it still would look somewhat blurred and layered. This is the brain postprocessing outsmarting our technology.

Easy fix? You can use a lower framerate if you add the blur. This is why we can sit through movies at 24 FPS, or TV at 30, since the recording equipment is averaging it for us. Of course, we can still sense the "syncronous" nature of the screen updating, especially when comparing camcoder stock at 60fps and movie stock at 24.

But you don't need to update the screen nearly as fast. 60fps with motion blur is about as realistic as one could ever hope for. Have you seen HDTV football broadcasts! My god!

So if Doom supports capping the output framerate at 60fps, but internally allows motion blurring by rendering at twice that followed averaging, I don't think you'll notice it at all. As far as your eyes are concerned, you're screaming at 120.

The one thing I think is a bad thing is that they chose 60. If this is vsynced on an analog monitor (necessitating a 60Hz vert refresh), it kind of sucks. I can "see" the refresh on lots of monitors at 60, but it goes away at 70. I'm sure many of you know what I mean.

I'd rather them cap it at 70, or 72. With 72 v. ref. you could update the screen at 24fps, tripling each frame, but rendering 3-6 frames when possible to create the blur.... LIKE WATCHING A REALTIME MOVIE. When it gets busy, just cut the number of frames you average.

That would be fricking cool.