Domain: havok.com
Stories and comments across the archive that link to havok.com.
Comments · 45
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Multiple possible comments
$30 GPS Jammer Can Wreak Havok[sic]
(Technical):
...which is why they are illegal in nearly every regulatory environment.(Snide): Gee, I didn't realize a GPS jammer could break an Intel SDK! Oh -- you meant havoc?
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Re:Maybe
Maybe there is some subtlety I'm missing by Havok is part of every PS3 and Xbox 360 SDK and plenty of Havok games were released on PS3 last year, check out the list from Havok themselves: http://www.havok.com/content/view/584/96
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Re:Havok
"Havok and the DX Physics are completely open and either party can use them, no proprietary api or licensing or anything silly. No hardware vendor controls what happens."
Completely open? What? DirectX is far from open, I'm assuming you mean free to use? You're also locked into Microsoft's platforms. As for Havok:
http://www.havok.com/index.php?page=pc-game-distribution-license-request
So er, just like PhysX then in other words.
"PhysX is not. It is controlled by Nvidia. Gosh, they wouldn't have financial motives to abuse this power would they? No of course not..."
See above, I'm not sure why you would believe there is no commercial entity involvement in DirectX Physics or Havok anymore so than nVidia's involvement in PhysX.
"Nvidia lately seems to have been getting around the whole market segmentation issue by
... paying off forum members in all the hot PC Hardware forums?"Ah, that must be it! Of course! If someone disagrees with you they're getting paid to disagree with you! Why didn't I think of that? YOU must be getting paid by ATI to disagree with me and I must be getting paid to disagree with you by nVidia. Now we know this we can just find a 3rd opinion and just agree on that because that must be the real truth right? Did you ever stop to think if a lot of people are predicting the death of AMD/ATI right now it might just be that the majority of people (including me) just aren't particularly impressed with the turd AMD/ATI have thrown out recently? I've seen periods where nVidia has gotten just as much of a pounding on forums, what does that mean? that ATI was just throwing more money to pay people off to slag off nVidia at that point than nVidia was paying vice versa?
"still waiting for a game where it actually adds anything"
Well, one of the first was Ghost Recon Advanced Warfighter which has been out years, there's plenty more though. Lots of engines provide integration as default or at least provide integration paths.
Does it suck what nVidia is doing? Yeah, I guess so if you're an ATI user. On the same note though it's hard to see why nVidia should support their opponents platforms, that's just bad business and really, the only people who suffer are people who aren't actually their customers anyway. I can see why they're doing it, it just makes good business sense.
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Havok anyone?
http://en.wikipedia.org/wiki/Havok_(software)
I think this list covers it: http://www.havok.com/content/blogcategory/29/73/
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Adobe AtmosphereAnyone use/remember Atmosphere? After years of a fun beta, Adobe pulled the plug at 1.0.
What was neat about Atmosphere was that it was intended to be like a 3d webpage. You built the world then hosted the files yourself, embedded in a webpage. If you wanted to add the chat/avatar stuff, they ran a server (supposedly open source) to manage that.
Yes, the penis avatars showed up quickly, but you could javascript restrictions to only allow avatars from certain domains, control animations, make fog, respond to user events, interact with the host page, etc. That gave it the flexibility to be so much more than a "3d chatroom."
Viewpoint meshes were supported, but primarily you built with primitives. Native objects had the lightmap precalculated with a nice radiocity lighting. Texture, light, add sound, Havok physics... I'm sad it's gone but the market just wasn't there.
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Here's the problem with thisThere is no common, open API for physics. Rather, there are several proprietary, closed APIs which offer similar functionality, but have no common specification. For instance, there are Havok, Ageia, Open Dynamics, and Newton, just to name a few. The PhysX chip from Ageia only accelerates games written with their proprietary library in the game engine. Other games written with Havok, for instance, should receive no benefit at all from the installed PPU. On the other hand, Havok and NVIDIA have a GPU-accelerated physics library, but games without Havok (or users without NVIDIA SLI systems) won't get the benefit.
On the other hand, graphics cards make sense for consumers because there are only two graphics APIs, OpenGL and DirectX, and they offer very similar functionality under the hood (but significantly different high-level APIs). So a graphics card can accelerate games written with either OpenGL or DirectX, but that's not the case with the emerging PPU field. In graphics, the APIs developed and converged on common functionality long before hardware acceleration was available at the consumer level, but I don't think the physics API situation is stable or mature enough to warrant dedicated hardware add-in cards at this time.
However, I think there are two possible scenarios that could change this.
1) Havok and Ageia could create open or closed physics API specifications and make them available to chip manufacturers, e.g. ATI and NVIDIA, which have the market penetration and manufacturing capability to make PPUs widely available. I could imagine a high-end PCIe card that had both a GPU and a PPU on-board.
2) Microsoft. Think what you will about them, but DirectX has greatly influenced the game industry and is the de-facto standard low-level API (although there are notable exceptions, such as id). Microsoft could introduce a new component of DirectX which specifies a physics API that could then be implemented in hardware.
But unless one of those things happens, I don't think proprietary PPUs are going to make a lot of sense for consumers.
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Here's the problem with thisThere is no common, open API for physics. Rather, there are several proprietary, closed APIs which offer similar functionality, but have no common specification. For instance, there are Havok, Ageia, Open Dynamics, and Newton, just to name a few. The PhysX chip from Ageia only accelerates games written with their proprietary library in the game engine. Other games written with Havok, for instance, should receive no benefit at all from the installed PPU. On the other hand, Havok and NVIDIA have a GPU-accelerated physics library, but games without Havok (or users without NVIDIA SLI systems) won't get the benefit.
On the other hand, graphics cards make sense for consumers because there are only two graphics APIs, OpenGL and DirectX, and they offer very similar functionality under the hood (but significantly different high-level APIs). So a graphics card can accelerate games written with either OpenGL or DirectX, but that's not the case with the emerging PPU field. In graphics, the APIs developed and converged on common functionality long before hardware acceleration was available at the consumer level, but I don't think the physics API situation is stable or mature enough to warrant dedicated hardware add-in cards at this time.
However, I think there are two possible scenarios that could change this.
1) Havok and Ageia could create open or closed physics API specifications and make them available to chip manufacturers, e.g. ATI and NVIDIA, which have the market penetration and manufacturing capability to make PPUs widely available. I could imagine a high-end PCIe card that had both a GPU and a PPU on-board.
2) Microsoft. Think what you will about them, but DirectX has greatly influenced the game industry and is the de-facto standard low-level API (although there are notable exceptions, such as id). Microsoft could introduce a new component of DirectX which specifies a physics API that could then be implemented in hardware.
But unless one of those things happens, I don't think proprietary PPUs are going to make a lot of sense for consumers.
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Re:No it won't
Here's why I disagree. There are several titles currently out that will never make it to the Mac because they use the Havok physics engine. This includes Half-Life 2, Tom Clancy's Ghost Recon Advanced Warfighter and The Elder Scrolls IV: Oblivion. Guess what? If I own an Intel iMac or MacBook, I'm buying Windows so I can play these games. That also means I'm going to buy a bunch of other games that are out for the Mac, but cost a heck of a lot less because they're in the discount bin, whereas the Mac version is full retail. I know this both as a long-time Mac user & long-time gamer.
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Re:follow Nvidia into Physics?
I'm definately a far bigger fan of Havok's sli physics for nvidia than a 1GB video card. I wish ATI would spend half as much effort not making crossfire such a piece of crap.
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not just Nvidia - Havok too!
The summary doesn't mention it and the article is really slow to load, but this is a joint project between Nvidia and Havok (the physics engine from Halo 2, Half-Life 2, and a bunch of other games).
There's some more information over at Gamasutra and Havok's site.
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Re:A Jokedifferent man and different company
Also, completely different concept.
Spore isn't exciting to me just because it looks like it'll be a really cool game. It's exciting because the ideas behind it could infuse some new life into the industry as a whole. The idea of giving players very simple, intuitive tools with which to create content, to actual make that content creation part of the game itself (as opposed to something you do externally with modding software) is promising.
Also, nice as the quasi-online element of Spore sounds to be, I long to see how this concept might be applied to more traditional online games, such as MMOs. With just a bit of extension, I could see the technologies being created/exploited in Spore applied to an online version of Starflight or The Ur-Quan Masters, but with even larger slices of the galaxy and more detailed planet surfaces, life forms, etc. and alien ships that you encounter are not pre-scripted encounters with NPCs (or at least, not all of them) but interactions with other players. Or your more traditional fantasy MMORPG, where instead of fighting the same re-textured orcs and rats for six months, each new area you explore features completely new monsters.
Best of all if they could combine these technologies (easy to use tools for developers and/or players to create stuff, procedural generation to breathe life into these creations and to populate vast landscapes very quickly), with other features and technologies that have been growing in popularity and maturity over the past couple years, such as realistic physics, destructible environments and more robust AI. This could open the door for a persistent world that is truly mutable, where players are free to create, destroy and explore an almost unimaginably vast world. It could be the ultimate sandbox experience that could combine aspects of various beloved genres as well (FPS, RPG, whatever).
If Spore itself doesn't qualify as something awesomely different from everything that has come before, then at least it could be a big step towards a game or games that do qualify as such.
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havoc
It's actually havok complete. (Havoc with a 'k').
In case you don't know who Havok is, here's their client list.
Most notable being Max Payne 2, Half-life 2, Halo 2 and Painkiller. -
havoc
It's actually havok complete. (Havoc with a 'k').
In case you don't know who Havok is, here's their client list.
Most notable being Max Payne 2, Half-life 2, Halo 2 and Painkiller. -
havoc
It's actually havok complete. (Havoc with a 'k').
In case you don't know who Havok is, here's their client list.
Most notable being Max Payne 2, Half-life 2, Halo 2 and Painkiller. -
Hyped AI
From the article:
"It's little surprise only Valve have really gone down this path properly as it clearly took a lot of work making the "cut-scenes" unbreakable by the player." Rather, they just ignore you and run through the script regardless (even if you shoot them, drop heavy objects that should kill them onto them or block their path with items they should not be able to move).
For example, if you block a path the game doesn't want you to (including dynamically 'in game', not just 'in cutscenes') the game would completly disregard the usual rules of physics and simply walk through pushing aisde any and all obstacles like they were made of cardboard (making setting interesting traps impossible in some area's, it's clear your supposed to 'stick to the rails' - like so many games thinking outside the box is not encoraged).
Of course playing with things like grary's modshows this isn't a limiation of the HAVOK physics engine - the best thing about Half Life 2 IMO, and which is entirely 3rd party - it's just the way Valve implimented it.
Half Life 2 is nowhere near as impressive as the origional was for the time IMO. Admittedly the origional had lots of distinctly tedious jump puzzles towards the end, but in the first half it had far more atmosphere and felt much more immersive to me. This is not just a case of seeing it through rose-tinted glasses either, I've played it through again recently and it's still head and shoulders above HL2 IMO.
To me, it just seems like Half Life 2 is riding entirely on it's use of the HAVOK physics engine, which of course lots of other titles have used (Halo 2, Ghost Recon, Max Pane 2, Full Spectrum Warrior, and many more) it's just that Half Life 2 use it _so_ extensively and happen to give the player a really fun toy to use to manipulate objects.
Sure I think the artwork in HL2 was okay, but the underlying engine quality was poor IMO - with kludges like the use of 2 sprites and careful map design used to try to cover up problems with a lack of proper LOD handling (with large objects like whole ships just appearing and disappearing at random in front of you on the beach, and things like tree's being redered as 2D sprites - Yuck!). The lack of a decent lighting model was pretty prevolent in some areas (something well discussed), though I was equally urged by dodgy map design featuring such delights as points where enemies could infinately spawn from points apparently in mid air (the sort of crap Doom 3 pulled and that is a big no-no in my view).
I found it particularly disappointing because we know they are capeable of better. -
Re:so..
They do directly sell land by auction (can't link because that portion of the site is subscriber-only). They also have an option where you can own an entire server. The 256K sq. meter option is an entire simulator (they call it a "sim" for short).
I have no idea of how much CPU and memory running one requires, but considering the game utilizes Havok Physics and most functionality is programmed in the Linden Scripting Language, it probably takes a respectable amount of each.
The bandwidth use is probably hefty as well, because network updates between X players concentrated in a small area are on the order of X ^ 2. The game animates everything your avatar does -- if you type in chat on your keyboard, your avatar indicates you are typing with an animation and particle effect. If you mouse over something in the game, your avatar turns its head to look where you're pointing. If you click to interact with a game object, your avatar gestures. All those little updates amount to a lot when you have thirty people close together all doing them at once and every action is broadcast to the other 29. -
Re:I have a bridge for sale
This is not a scam.
Second Life is just like the web, but wrapped in a pretty 3D virtual world - it is primarily a place where you can create and host content for others to enjoy (and purchase).
Land is a metaphor for server space. The money you pay is for the server resources. There is a finite amount of them per server (65536 sq.m.)and if you want, you can even buy your own server. Some people own more than one! Even major RL corporations are starting to hit SL - if you're a student, or unemployed, you could get yourself a real job!
Artist? Programmer? Just plain bored? Join Second Life - I've been there for over two years and will never look back.
You can build just about anything out of simple geometric shapes and make it come alive with a powerful, yet simple scripting language that uses C/Java style syntax and an event-driven paradigm.
Check out the language reference and see for yourself!
Second Life even includes a full fledged physics engine called Havok, which is rapidly becoming the industry standard.
It is truly a geek's dream come true, and no one on SLASHDOT of all places should dare criticize it - we have a whole section devoted to LEGO and SL is at the very least LEGO on steroids :)
Heaps of screenshots -
Re:Interesting idea
so..
does all the games that use havok feel the same?
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Re:Interesting ideaSo with a PPU, you have to decide on a common library of collisions. Good news: more objects you can play with and let the PPU decide what's getting hit. Bad news: everybody's game will react basically the same and they'll have to decide if that's a good idea.
It looks like we're heading there already. Havok has already developed a mature software physics engine which is used in many popular games. I think in this case, developers are willing to give up a little control on physics to have better looking effects. This PPU sounds like it's designed to hook right into Havok, and could really prove useful as Havok becomes more popular.
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List of titles
They publish a list of titles that use Havok. You'd be suprised what all is in there, its not just first person shooters.
HAVOK Title list here. -
Valve did NOT make the physics engineThey licensed it from Havok.
HL2 is a great game. But give Havok its proper credit.
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Re:Taking the Steam out...
Do your homework.
http://www.havok.com -
Linux root access
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Re:So it plays like Farcry?The Havok engine is what powers the physics of the game (IE: ragdoll physics of the bodies), not the entire game.
Source is the game engine that renders the graphics.
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Re:Is CS still THAT popular? How?
Hey dude,
If you want an idea of what's new, Google for "hl2 shakeycam video". Watch it and wait until the end.
It's painfully bad quality but interesting nonetheless.
Hey, everyone realises that hl2 uses the Havok Engine for it's physics right?
Cheers
Stor -
Re:So this means..
that there actually exists some code!?
Yes! It's available here.
Cheers
Stor -
A different approach?
Being one of the aforementioned poeple whose lifelong dream is to make games for a living, this issue is one of my biggest concerns. Much as I'd love to design and/or code games for a living, I'd also like to see my family more than once a month. Maybe its not realistic of me, but I'd like to think that much of this problem can be eliminated through a combination of more realistic scheduling and careful design, stressing re-use of components. There are starting to be some impressive third-party game development libraries out there (Havok comes to mind) - between libraries like that, and well-designed, re-usable in-house components like GUIs, factories, event systems, and other such suitably generic components, much of the development time can be cut down, at least after the first game to use them is developed.
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For that, you buy HavokThat's what commercial physics engines like Havok are for, The Havok engine on the Playstation 2 reportedly uses the vector processors, so special purpose hardware is already being used.
Massive parallelism is helpful to a physics engine, as are lots of fast FPUs. (Preferably double precision. Single precision in a physics engine requires workarounds for the low precision, if the world is at all big. You lose precision when far from the origin. The PS2 has single precision floating point only, which is a headache.) You do lots of 4x4 matrix multiplies, so the same kind of hardware that appears in the geometry-acceleration part of a GPU is helpful. There's not much use for the back end of a GPU, with the frame buffers, Z buffers, and fill engine.
The hardware requirements for a physics engine look much like those for a number-crunching supercomputer. That's not surprising; the calculations are quite similar. Amusingly. the biggest supercomputer today, the Earth Simulator in Japan, has a architecture that looks vaguely similar to a PS2.
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Re:Collision detectionODE is still at version 0.039, and not improving much.
Reliable dynamics simulators are hard. If you want one for a commercial game, there's Havok 2. All the free stuff is very limited.
It takes years of hard work to write a physics engine. If you're competent, in six months you'll have something that sort of works. From "sort of works" to "works" is years of effort. And it's not patches. It's theory. So the open source process doesn't work very well.
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Re:Another sad thingGame development has become so complex that there really is no hope for a small team or a startup to make a decent game.
I don't know about that, I'd played the Painkiller demo and it looked really neat, an original engine, huge levels, Havok physics, dozens of monsters at the same time without slowdown. I was blown away that it was done by 20 guys in Poland. And one of the most talked about games is S.T.A.L.K.E.R. coming out of Ukraine.
Thats the loss I mourn... kids wont ever have the fun I had trying to make a game, and we might never be exposed to some new ideas these kids might have.
Nah, they'll have fun working on Half-Life II mods and Shockwave games (some of the stuff on the Havok XTRA site looks like it could be done by beginners), sure it's not working from scratch but I bet you didn't write your own compiler either.
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Re: Umm... howbout "no", Scott.
*Bzzt*, both of you are wrong, sorry.
Havok is the physics engine behind Half-Life 2. And Dues Ex 2, Freelancer, Max Payne 2, Thief 3... you get the picture.
The actual game/rendering engine behind Half-Life 2 is called "Source", and it was made completely in house at Valve. You can't play with it yet though, not until Valve releases the SDK anyways (which is supposed to be "soon", which, knowing Valve, means 6-8 months). Well, that is assuming Valve isn't "hax0rd" again. *Groan* -
Re:Try a game you like that popular.
lol, Ya, Guess the Havok2 engine would be on par with HL2 engine, it IS the halflife2 engine.
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ATI 9700 pro
I upgraded from a GF3-TI500 to an ATI 9700 pro, almost as fast as the GF4-4200 or ATI 8500. At the time (2002) it was the king.
I first tried the Nvidia GF4-4600 for 199, and it didn't even feel faster(took it back). The ATI 9700 Pro, Ati's main comeback into the game, really was impressive. It was worth every penny (39,900 of em).
Anti-Aliasing was the new kid on the block, and the ATI 9700 pro allowed all games at the time (and most now) with AA turned on. Toms benchmarks shows the ATI 9700 pro still to be in the top 10. With video cards not doubling in speed every 6 months anymore (i miss you 3dfx), I dont expect to see the speeds jump like they use too. This card might just last me another year, and in the last 6 years, thats amazing in gfx card releases.
The only problem I've seen so far, is Nvidia's CG code really messes with ATI's textures and shaders. And with lots of developers loving Nvidia SDK's. ATI has been good to fix most bugs with ever new Catalyst release, but I'm still waiting SecondLife to get patched. (Nvidia CG bugs) Such a work horse of an engine (Havok), should be interesting to see Havok2 engine used. (Also used in Max Payne2)
The benchmark had me wondering, why only a P3.2ghz? I'd like to see them also include a High End AMD, and both mid range (2.6hz P4, AMD 2600) to round it out. Always wonder how many more FPS a faster CPU will give me, so I can just if its worth the cost. BTW Save those pics from toms hardware, then you can compare hardware later. I had to search the tomshardware.de for the benchmarks I was looking for 2002.
Hey, lucky they didnt use a P4EE ;)
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Re:I've always wondered when this would happen...But what I'm really looking forward to is a Physics specific processor that sits alongside the graphics processor, and is resposible for collisions detection.
It's been done. The Havok game physics system is available for the Playstation 2, and the physics is running in the vector processors, where most of the PS2's compute power resides.
Collision detection isn't that CPU-intensive. (This may surprise people not familiar with the field. But it's true. If collision detection is using substantial CPU time, you're doing it wrong.) Correct collision resolution is where the time goes.
Physics code works better with double-precision FPUs. You need both dynamic range and long mantissas to do it well. Some of the game consoles, and most of the GPUs, only have single-precision FPUs. It's possible to make physics code work in single precision, but fast-moving objects that cover considerable distance may have problems.
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Re:Havoc
It's Havok, not Havoc.
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Pretty Much Offtopic
After following the links to the Havok website, I managed to get to a page featuring videos which show off what their physics engine can do.
I'm just wondering if they actually know or care how big their .avi files are since they seem to make up random sizes.
Video #1 - listed as 6.9MB, actually 9432KB (9.2MB)
Video #2 - listed as 7.9MB, actually 7218KB (7.0MB)
Video #3 - listed as 7.9MB, actually 6764KB (6.6MB)
You'd think they could at least come a little closer to the truth. -
Re:Borrowing a bit?
You do realize that Half-Life's physics engine isn't actually Half-Life's, don't you? It is the HAVOK physics engine, long used in the 3ds max plugin known as reactor.
As for whether it is more functional than the physics simulation contained within the Doom 3 engine; in my opinion, it is too soon to tell. -
Re:Pressure = opportunity
One such physics engine is Havok which is featured in games such as Half Life 2, Grand theft auto 3 and Deus Ex 2. Though they often use eg only the physics engine most parts of a standard game engine are present in Havok. (Graphics, sound, physics and AI at least.)
Considering how powerful computers and consoles are getting there is less need to have everything custom made for a game. Often you can buy or licence an existing engine and save a lot of development time and effort. (And money.)
Id software and other companies have been making quite a lot on licensing engines. And when you think about it the entire mod community is based on the idea.
So I wouldn't say that the idea is a bad one, I'd just say that it's already been done for quite a while. ;-) -
Re:HL 2 Mighted have changed thingsAlso, HL2 certainly comes to mind real fast due to
automatic physical interactions/collisions between hard surfaced objects
more deformable surfaces
more idle objects being first class entities
deformable entities
facial animations
The D3 clip had better rendering (pixel shading if you will) and better detailed animation, but that may simply not be enough.All these features seem come from the Havok engine, which I've seen in a number of preview clips now, and its awesome. I would not be surprised if the Doom3 publishers saw it and its mid-sept release date and started passing large building blocks.
I also wonder about the xbox-delayed release. Its known Microsoft has offered big money to have an xbox version ready at release, which entails more waiting. John C said they did not want to show the same game at multiple E3's - and they have and then some. Could D3 have been an xmas 2002 game? is it stagnating in the can like Halo in 99, now being tarted up?
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Re:What all 3D games are really missing
Physics is infact the next big thing in gaming.
There are several real time physics libraries out there which several game companies have licensed. Expect to see them in action in Deus Ex 2, and Doom3 (But I suspect Ids making their own phyisics package, at least I haven't heard that they've licensed one).
The first things we'll see are objects falling over in a realistic way. Often referred to as rigid body dynamics, which is exactly what it sounds like.
Ragdoll physics for bodies which will now tumble violantly down staircases, rest against walls instead of falling into them, etc. Realistic particle physics that will let steam and smoke move and be affected by the turbulence caused by the characters or missiles (seriously simplified, but still pretty
darn cool)
All these features are already in the new Unreal Engine. Also expect to see some soft body dynamics like cloth, rubber and jello for the next iteration of physics engines. The features are there already, but are currently a bit too computationally intensive for todays games.
Some links.
Havok
Open Dynamics Engine
Mathengine -
Why game physics is hardI'll have to take a look at this new book, but from the description, it looks like the author doesn't address the hard problems. Alternatively, the reviewer may not know what to look for.
As someone else pointed out, there's a straightforward way to approach game physics, based on what you learn in a first-year dynamics course, and it won't work. Free flight is easy. Contacts and collisions are hard.
Detecting contacts between objects is complicated, but well-understood. There are several free collision-detection engines available, and many research papers. The time bounds are quite good; only slightly worse than O(N) with the better algorithms. Writing a collision detection system is a big job, but the theory is tractible.
Taking appropriate action when you detect a contact is the hard part of the problem. Bouncing balls are easy. Multiple irregular objects with multiple contacts, slipping and sliding, are hard. Most current games simplify their collision geometry down to cubes or spheres and botch the hard cases ("But my sword went right through him and he didn't even notice!") The latest generation of games is just starting to get contact right. In another year, correct contact handling will be a "must-have" for commercial games.
If you simulate contacts between objects with a spring and a damper, you run into numerical stiffness during integration. Soft objects at slow speeds will bounce fine. In a hard collision, the forces become huge for short periods. The simple integration algorithms will result in huge errors, and the objects will go flying off into space.
If you simulate contacts between objects as impulses (an impulse is an infinite force applied for zero time, but with a finite energy transfer), two objects bouncing off each other will work great. More than one contact per object doesn't work too well. Resting contact doesn't work; objects may fall through each other. And everything bounces like it's a pool ball, because all collisions take zero time.
If you try to do everything with constraints, resting contact works. But combinations of sliding and resting contact result in wierd corner cases that are hard to get right. Trying to solve contact, rather than simulate it, leads to static indeterminacy. (Think of a table with four legs, slightly different in length. How the table behaves is very sensitive to small changes in leg length. Numerical solutions of multipoint contact problems become similarly sensitive). This is the approach Baraff preaches at SIGGRAPH, but few others have been able to implement it.
After a few years on the problem, I developed Falling Bodies, which successfully solves this problem well enough to simulate a human figure falling down a circular staircase. It can be done. I hammered through the spring-damper problem by using unusual and robust integration techniques. This is computationally expensive, but sound.
If you're developing a commercial game, and need working physics, go with the Havok engine. They have a rigid body engine, a soft-body system, and a specialized vehicle simulation engine. (Yes, vehicle physics in games typically has fake components. In most racing games, the tires are impossibly good and the vehicle CG is impossibly low. But you need a real physics engine to fake it properly.) It's not cheap, but you're not going to solve this problem in a few months. Major developers have blown years on this problem and failed. Trespasser, from Dreamworks, went down the drain that way.
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Re:Enough with the polygons - lets get some physicDefining a "unified physics API" isn't that hard. Havok and Mathengine each have one. It's making the engine behind it fast and reliable that's hard. There are still tough theoretical problems in this area. But we know how to do it right; efforts now focus on getting more speed out of the algorithms. The ever-faster hardware helps.
Did you see the claimed numerical performance for the new NVidia chip? 100 gigaflops. I can hardly wait until we have that kind of performance in the main CPU(s).
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physics can be offloaded to a rich APIHavok is an Irish company who have written a full newtonian physics engine for win32 and PS2. Their site has loads of information on it (not necessarily technical, but lots of demo movies and actual demos). They even have two demos which showcase cloth in particular.
I've also checked out some of their competitors (mathengine, etc) and havok seems miles ahead. Unfortunately, I don't think havok supports any open source platforms.. I can't imagine they're not working on that, though.
cheers,
-o -
physics can be offloaded to a rich APIHavok is an Irish company who have written a full newtonian physics engine for win32 and PS2. Their site has loads of information on it (not necessarily technical, but lots of demo movies and actual demos). They even have two demos which showcase cloth in particular.
I've also checked out some of their competitors (mathengine, etc) and havok seems miles ahead. Unfortunately, I don't think havok supports any open source platforms.. I can't imagine they're not working on that, though.
cheers,
-o -
More d/lable demos
Havok have lots of physic simulation demos - including one of cloth. The dancers are pre-programmed but the cloths movement happens in real time.