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Carmack's QuakeCon Keynote Detailed
TheRaindog writes "In addition to announcing the Quake III source code's impending release, John Carmack's QuakeCon 2005 keynote also covered the programmer's thoughts on Microsoft and Sony's next-gen consoles, physics acceleration in games, and what he'd like to see from new graphics hardware."
http://www.filerush.com/download.php?target=QuakeC onCarmackKeynote.zip
The actual keynote speech
The only things certain in war are Propaganda and Death. You can never be sure which is which though
I was a bit taken aback by Carmack's opposition to procedural textures. No, they can't do everything but they can be real timesavers when you need to add some overall realistic looking details. Things like dirt, "roughness" and stains can be done effectively using Brownian noise and the like, and you've got the infinite resolution, low-memory features of procedurally generated data. It's efficient and looks good, especially when I used it to create realistic terrain.
Of course procedural textures can never replace hand-painted detail, but layering on some infinite-resolution noise-detail onto a finite sized bitmap texture really brings materials to life.
Lets talk about Jon Carmack. Jon is the legendary programmer of such classic PC games as Wolfenstein, Doom, Duke nukem 3d, Quake 1, 2, and 3, unreal, and the upcoming doom3. Jon has single handedly created the genre known as the first-person-shooter. He has also popularized the OpenGL 3d format over Microsoft's competing Direct3d format, as well as caused public interest in 3d cards when he first released accelerated quake for the s3 virge chipset. Jon carmack has redefined gaming on PC's.
Now stop for a moment and think, What would have happened if Albert Einstein had worked creating amazing pinball games instead of creating the theory of relativity? Humanity would suffer! Jon carmack is unfortunately doing JUST THIS, using his gifts at computer coding to create games instead of furthering the knowledge of humanity. Carmack could have been working for NASA or the US military, but instead he simply sits around coding violent computer games.
Is this a waste of a special and rare talent? Sadly, the answer is yes.
Unfortunately, it doesn't stop there. Not only is Jon carmack not contributing to society, he is causing it's downfall. What was the main reason for the mass murder of dozens of people in columbine? Doom. It's always the same story: Troubled youth plays doom or quake, he arms himself to the teeth, he kills his classmates. This has happened hundreds of times in the US alone. Carmack is not only wasting his talents and intelligence; he is single-handedly causing the deaths of many young men and women. How does he sleep at night?
Carmack is a classic example of a very talented and intelligent human being that is bent on total world destruction. Incredibly, he has made millions of dollars getting people hooked on psychotic games where they compete on the internet to see who can dismember the most people. I believe there is something morally wrong when millions of people have computerized murder fantasies, and we have Jon Carmack to thank. Carmack has used his superior intellect to create mayhem in society. Many people play games such as quake so much that their minds are permanently warped. A cousin of mine has been in therapy for 6 months after he lost a 'death match' and became catatonic.
It is unfortunate that most people do not realize how much this man has damaged all the things we have worked hard for in America. Jon has wasted his intelligence, caused the deaths of innocent children, and warped this country forever. To top it off, he got rich in the process and is revered by millions of computer users worldwide. Perhaps one day the US government will see the light and confine Jon Carmack somewhere with no computers so he can no longer use his intelligence to wreak havoc on society.
> ...as soon as the developers made their games multi-threaded
:)
This is considerably more difficult than one would think. Games typically have to perform tasks in a particular order, for example (extremely simplified): get inputs, move player, move AI players, move other objects, check for collisions, update parameters, display the next frame, loop.
Quite where we add this 2nd thread is difficult. Everything must happen in the same order in order for things like collision detection to function correctly. If we start a second thread to, say, calculate AI decisions and move the AI characters according to those decisions, we have to wait for that thread to complete before we can display the next frame. So it ends up that there are no advantages to utilising that second thread.
Now, I'm sure there are game developers on here who know how to utilise threads in games in a successful way. It'd be cool if one of them could inform the rest of us what the heck we're supposed to be doing with them
"You heard the man, Tubbs.. get undressed."
- Add to unprocessed que
- Grep for coded expressions
- add symbol to character action queue
Thread 2: Charactor Thread- read action queue
- publish action
- recieve reaction
- update state
Thread 3-100: AI Threads- Read viewable universe state
- Process against goals
- publish action
- recieve reaction
- update state
Please don't read this too literally, it only a slashdot post, but this is meta-outline of how I'd start thinking about the game universe in a multi cpu system. Of course it would run like shit on a single CPU (all those context switches (ugh)), but it would really utilize a multicore system.Scared of flying, pointy things snce 1979!
Quite where we add this 2nd thread is difficult. Everything must happen in the same order in order for things like collision detection to function correctly.
Not neccesarily. One big problem with games is that the typical order (beginscene/render/endscene/present) is implemented with a busy-wait loop in the present part. This is the part where all data has been sent to the graphics card and the driver waits in a loop until it gets a 'scene completed' message from the card. This is why games always run at 100% CPU.
Games that don't use threading well (only threading for network/input/sound) put stuff in the loop you describe. Draw a scene, the driver waits for an 'OK', then you update the player, update the AI characters, do collision, calculate all new positions and start drawing. Because the drawing takes eg. 10 ms per frame for 100 FPS developers limit the AI/collision part to run in something like 1 ms or else the frame rate starts dropping. So the real AT would be limited to say 10% of the CPU time.
For example the 'move AI' part could be a bunch of threads, calculating new positions based on direction, collision etc.
Right now games like DOOM3 typically only display a few NPC's at the same time because of the timing problem. If the move AI thread can just keep running on the second CPU while the first CPU waits within the driver a game could support a few 100 enemies on-screen.
Strategy games with complicated pathfinding with hundreds of units on-screen like Warcraft 3 or Age of Mythology would profit enormously, if programmed for multithreading.
Although Mr.Carmack says physics in game engines isn't easily scalable for level of detail, there is ongoing research about this producing good results. I remember a video from last years SIGGRAPH that had hundreds of plastic chairs falling from the sky, and bouncing realistically. The important part was it employed a level-of-detail hierarchy for interacting parts (i.e. an object doesn't have much physical detail if you don't touch it), but it will be some time before we can see such techniques in real time games.
I think you're misunderstanding his point. When he talks about level-of-detail, this has more to do with game design than with algorithms. What he's claiming is that detailed physics has much more of an effect on actual gameplay than detailed rending does, and that it's harder to write a game which graceful downgrades the player's physical interaction with the world. But a graceful downgrading is necessary for people who don't have a fancy physics-accelerating card.
For example, you can take an older game and change its appearance by giving it higher resolution textures, more detailed meshes for the AI models etc., without having to redesign the actual gameplay. (e.g., the SHTUP and Rebirth mods for System Shock 2).
These steps are independent of each other and independent of the rest of the game. They can simply be dropped in, or not. The point is that if it's that straightforward to take a game forward in technology, it's even easier to go in reverse. So the player can choose low texture detail, etc., and the game may look worse, but it will still play the same.
The game physics on the other hand has historically been more closely connected to the way the player interacts with the world.. so it has a big effect on level design. If Half-Life 2 had a 'simple physics' option that would somehow revert the game physics to something equivalent to the physics in the original Half-Life (ignoring aside the difficulty in implementing such an option) then some areas would have to be substantially redesigned so that they would remain playable for people using the simple physics.
This is of course what he means by peripheral elements "such as flowing water" being accelerated. But I have two criticisms of this.
1) Yes, physics acceleration may affect mainly peripheral elements of the game. But in some ways, the same could be said about improved textures, filtering, etc. If it's done well, it can significantly improve the overall experience. If it's done poorly, the player will hardly notice.
2) As long as it's an upgrade of the basic design, it will probably be okay to let it affect critical elements as well. E.g.: due to the engine upgrade in the port of Half-Life to the Source engine, movable crates and such have a more realistic response than in the original implementation. It's not a big improvement, since the levels were really designed with that in mind. But it doesn't hurt.
For me, the real question is whether improved physics would really make a game more enjoyable. I think this depends more on graphics than on anything else. As objects are made to look more realistic, it becomes more satisfying for them to have real-seeming interactions.
If graphics get much better, accelerated physics will be important. But if for some reason graphics tend to stabilize (due to the end of Moore's Law, long load times caused by slow disk access, or whatever), then the usefulness of improving game physics is more questionable.
If only there was some way for you to be able to decide not to buy Carmack's games.
But I guess that's just impossible.