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  Physics performance challenge to J.Kesselman...  (Read 17700 times)
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Offline philwebster

Senior Newbie





« Reply #30 - Posted 2004-04-17 14:07:13 »

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$500 dollars, in sterling is about 250 quid? (or is it the other way round?). (hopefully they'll be alot more than that, I wouldn't even bother, but then maybe I don't care enough)

US$500=UKĀ£280
Like I said, participants should chip in some of their own cash for  the prize fund. I'm not funding the entire thing.

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Before anyone starts putting money down it might be a better idea to set out and AGREE rules, intention and what needs to be created to get reasonable results.

Of course. But without the money, I expect this discussion would have ended by now. So let's agree on rules. Anyone?

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I'd also suggest that no-one with a vested emotional interest get involved.

I don't intend to contribute any code to this experiment, although I'm quite happy to spend my own money on it. Who exactly are you referring to?

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As to Jeff, by the look of his last comment he's not interested in getting involved. Doesn't mean its not a pefectly valid experiment. I do think the cash pot would have to grow a fair bit to get people that know what they're doing involved.

If some good rules turn up, I might be pursuaded to throw in a bit more. Jeff's probably loaded - why doesn't *he* contribute some! ;-)

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With respect, the "first" (and subsequent) replies Jeff gave on the blog discussion were polite and "fairly" open (given his obvious employment based bias). While some of Jeffs comments have been patronising or possibly flippant, can you not also see that some of yours haven't been exactly diplomatic either? (but then I suppose no-one ever is immensely polite on the internet)

There's nothing wrong with asking for evidence. What exactly is wrong with my posts? Give me an example!

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Again, I'm not quite sure why this discussion which seemed to be going pretty well on the blog made its way here?

Part of the reason is the way that healthy weblog discussions sink into the Quicksand of Obscurity, regardless of the discussion's popularity. PHPBB and other 'real' discussion systems typically bump a thread to the top of the list, which is much more useful both as a navigational aid for regulars and as an attractor for visitors.

But it is a good idea to occasionally cross-post summaries of the discussion here onto the weblog comments.
Offline philwebster

Senior Newbie





« Reply #31 - Posted 2004-04-17 14:12:55 »

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So, are we saying "pure" Java only then? No JNI, seems a little unfair not to use a feature of the language Wink

I guess we need to some members of the games development community who know C++ and Java and know enough about physics engines and don't have preconceptions about either side.

EDIT: Incidently, whats your beef with the performance comparison of 9 languages posted above (and in the blog). Its not specific enough to game physics?

Kev


One of the stated advantages of Java in Jeff's weblog was that Java's portability would save devcos money. Native code isn't portable. He also said that Java was as fast as C/C++. So if it's just as fast, you wouldn't need to use JNI in the first place.

Isn't the HotSpot supposed to optimise away all those performance issues?  ;-)

What do other people think? JNI or no JNI? If so, why? If not, why not?
Offline andyl

Senior Newbie




Java games rock!


« Reply #32 - Posted 2004-04-17 16:07:44 »

I would restrict JNI to any existing JNI calls that the J2SE 1.4.2 library makes (this is necessary to allow people to use the J2SE library), and a standard binding to OpenGL. Anything else would be unacceptable as you'd have to use a different language compiler, and as mentioned in the previous post, Jeff assures me that Java can do just as good optimisation.

Perhaps I should make it clear that I am not interested in competing with other C developers, nor am I interested in comparisons to anything not implemented in pure Java. The point of my challenge, as noted above, was to bring this 'discussion' down to hard facts rather than bluster and spin, so I will supply a baseline native version that Java has to match.

And I'm not interested unless Jeff and his other experts are involved, as I don't want any excuses about the Java code being poorly written when the result is known.

As for needing games developers - no. I will publish all the maths required in the rules, otherwise it wouldn't be a fair comparison. Given this, any developer who knows the difference between a vector and a matrix should be able to implement a version, in something like 30-40 hours of work.

The simulation would involve a a large number of capsules moving around in zero gravity inside a box, bouncing off each other and the box walls. The use of capsules keeps the collision code easy for everyone to implement whilst still allowing rotation of the bodies without introducing friction into the simulation.

EDIT: Even though it's really up to Jeff to prove his assertions himself, I think the issue has become a matter of personal integrity (if you make assertions as a representative of an organisation then you should also be prepared to back them up). I'll stump up $500 as well.

I now count 4 digits, the figure Jeff suggested. I want to see this get to $3000 (approx. a months wages) to make it happen.

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I also think Mr. Larder had a good idea. But sincee's the one who cares he should put up the prize, at least 4 dgits worth.  If he does that I'm sure you guys would be happyto compete, wouldn't you?  (Sicne we are talking an individual that prize better be in  verifiable escrow account. and the contest rules clearly and legally stated.)


I'm glad you think it's a good idea Jeff - now where's your $500?
Games published by our own members! Check 'em out!
Legends of Yore - The Casual Retro Roguelike
Offline shawnkendall

Senior Member





« Reply #33 - Posted 2004-04-17 18:03:42 »

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EDIT: Incidently, whats your beef with the performance comparison of 9 languages posted above (and in the blog). Its not specific enough to game physics?

Kev
Why is this existing test not being used as the example? The code is available you can review and debate it merit here. And it is a complete set of test across several language....
Please explain your reasoning for dismissing this...

Shawn Kendall
Cosmic Interactive, LLC
http://www.facebook.com/BermudaDash
Offline andyl

Senior Newbie




Java games rock!


« Reply #34 - Posted 2004-04-17 18:20:45 »

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Why is this existing test not being used as the example? The code is available you can review and debate it merit here. And it is a complete set of test across several language....
Please explain your reasoning for dismissing this...


Hiya Shawn, glad to finally make your acquaintance  Smiley

That test was flawed in many regards:

  • The comparison was to GCC. Games developers use the fastest compiler available on each platform, not GCC. GCC is not comparable to Intels or IBM's optimising/vectorising/profile guided compilers.

  • It was no test of computational 3D geometry, i.e. 3D games coding. In my opinion the tests were the worst micro-benchmarks I have seen in quite a while.

  • There are many opportunities to vectorise code using SIMD, which the Intel compiler can do for you, or you can do yourself by inlining a few intrinsic functions into your vector and matrix cpp classes. Apple sped up a real application (Noble Ape) by 6x over C based scalar code just by adding a little Altivec code.

  • Have you seen the performance of the JVM on the Macintosh G5? If not I suggest you pop down to your lab or to Cupertino and check it out.


Andy.
Offline Raghar

Junior Member




Ue ni taete 'ru hitomi ni kono mi wa dou utsuru


« Reply #35 - Posted 2004-04-17 19:07:20 »

1000 $ is 3 months of comfortable live with slight computer updating, and after paing all taxes. I'm not interested.
It might be interesting to see what will Jeff create in his spare time, but how it would help to game community?
Worst case would be: Sun engeneers would be somehow distracted from theirs work. And possibly delay few important things.
Best case could be: You actually create something, that would be possibly helpful to the community.

So you claim that capsule (you mean sphere?) bounding in some "cube" will help the community?

Perhaps better idea would be. The best hack that would speed up JNI. If there are problems with JNI.

Or why not give that money to person that would finish Java to PS2 compiler?

Is VC 6.0 best compiler in the world? You claim that game developers are using fastest compiler...
Offline shawnkendall

Senior Member





« Reply #36 - Posted 2004-04-17 19:11:03 »

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  • The comparison was to GCC. Games developers use the fastest compiler available on each platform, not GCC. GCC is not comparable to Intels or IBM's optimising/vectorising/profile guided compilers.


Good point.  But then the source is available so recompile under compiler of your choice. But...(see next)
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  • It was no test of computational 3D geometry, i.e. 3D games coding. In my opinion the tests were the worst micro-benchmarks I have seen in quite a while.


If you don't like the test anyway, no reason to test under optimizing compiler, of course
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  • There are many opportunities to vectorise code using SIMD, which the Intel compiler can do for you, or you can do yourself by inlining a few intrinsic functions into your vector and matrix cpp classes. Apple sped up a real application (Noble Ape) by 6x over C based scalar code just by adding a little Altivec code.

  • Have you seen the performance of the JVM on the Macintosh G5? If not I suggest you pop down to your lab or to Cupertino and check it out.


Andy.

Well I don't exactly have the chance to take vacation time and fly out to Cupertino (anymore than the next guy I suppose) to check it out personally but then maybe you can?  Strange comment it seems to me.  
Maybe you can just post some kind of quantifiable specs on what you are talking abot here.  Or rather just say what you mean.  What would I see if I went to Cupertino and checked it out?

Regardless, if someone tells me something about some thing, and I say SHOW ME and they can't show me to my approval then I just go about my business.  What is the fire on your belly over this?  If you want to prove something to yourself, write the app.  If you want to prove it can't be done to everyone else write the app.
If you don't BELIEVE it can be done, then really aren't we talking religion and not facts?

In any case, what is your goal?

Shawn Kendall
Cosmic Interactive, LLC
http://www.facebook.com/BermudaDash
Offline Raghar

Junior Member




Ue ni taete 'ru hitomi ni kono mi wa dou utsuru


« Reply #37 - Posted 2004-04-17 20:01:46 »

Quote


Perhaps I should make it clear that I am not interested in competing with other C developers, nor am I interested in comparisons to anything not implemented in pure Java. The point of my challenge, as noted above, was to bring this 'discussion' down to hard facts rather than bluster and spin, so I will supply a baseline native version that Java has to match.

The simulation would involve a a large number of capsules moving around in zero gravity inside a box, bouncing off each other and the box walls. The use of capsules keeps the collision code easy for everyone to implement whilst still allowing rotation of the bodies without introducing friction into the simulation.

I would be nice. Collision detection between moving spheres in 3D space in double precission floating numbers took 144000 ms. It was bruteforce algorithm 30 000x 30 000
However I think that simulation would be flawed from start, amount of possible implementation is really high. How would you measure theirs effectivity? By FPS?

BTW What do you mean by physics engine?
Offline erikd

JGO Ninja


Medals: 16
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Maximumisness


« Reply #38 - Posted 2004-04-17 22:53:35 »

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However I think that simulation would be flawed from start, amount of possible implementation is really high.


That would not be a flaw in itself. IMO, one of the compelling reasons to use java is that it takes less time to write stable and safe code so you have more time working on the algorithms in the time you would need in the C counterpart to write stable and safe code.

Offline erikd

JGO Ninja


Medals: 16
Projects: 4
Exp: 14 years


Maximumisness


« Reply #39 - Posted 2004-04-17 23:13:53 »

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And by the way, where is this mythical FPS that supposedly runs as fast as Quake 2?


Try google or search the forum. You might find a well performing Q3 clone, and some benchmarks against VC with comparable results.
I searched and searched, but couldn't find any evidence of java being 7x slower than C on a mac. But then again maybe you're right, but until you show some evidence nobody will know.

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And I'm not interested unless Jeff and his other experts are involved, as I don't want any excuses about the Java code being poorly written when the result is known.

The odds are that there *could* be a decent java developer out there somewhere outside Jeff, you know Wink Why do you only want to challenge Jeff in person? After all, it's about java's suitability not Jeff's isn't it? What would be the point of a well performing java (or this whole discussion for that matter) if only 'jeff and his other experts' were able to achieve that?
Why challenge him here in a public community if you don't want that community to be involved?
You will prove nothing if jeff won't be involved for whatever reason; it won't prove any of your insinuations about Jeff's integrity that's for sure.

Games published by our own members! Check 'em out!
Legends of Yore - The Casual Retro Roguelike
Offline erikd

JGO Ninja


Medals: 16
Projects: 4
Exp: 14 years


Maximumisness


« Reply #40 - Posted 2004-04-17 23:37:30 »

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(believe it or not John Carmack takes an occasional rain check in this direction, but I don't recall Doom 3 being a pure Java game).

I do recall John Carmack didn't go for java because of a large codebase he has that's written in C and he thought after all it woudn't pay off do dump it and revert to java.

Offline andyl

Senior Newbie




Java games rock!


« Reply #41 - Posted 2004-04-18 00:01:55 »

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Regardless, if someone tells me something about some thing, and I say SHOW ME and they can't show me to my approval then I just go about my business.  What is the fire on your belly over this?  If you want to prove something to yourself, write the app.  If you want to prove it can't be done to everyone else write the app.
If you don't BELIEVE it can be done, then really aren't we talking religion and not facts?

In any case, what is your goal?


Shawn, it's interesting you have questioned my motives, a question JK should have asked.  I have implemented everything necessary to know what I need to know, so why indeed am I doing this?

Well, it started like this:

Jeff wrote an article suggesting positive reasons about why games developers should be using Java, and he also invited responses. I supplied a response which I hoped would encourage him and others at Sun to look at the issues that, at least from my point of view, show why games developers are not ditching C++ and adopting Java. When asked supplied reasons why I can pretty much do in C++ what he called advantages of Java, he resorted to patronising/insulting me. Quote 'The compelxity problem, which is what was identified and called "the software crisis" 25 years ago, is well recongized as a critical problem in the industry today. Maybe the right answer is to have you personally retrain the industry'. Is this the kind of professionalism you would expect of a representative of Sun to one of the developers he should be trying to win over, especially as it was only provoked by a technical discussion? I don't accept what JK asserts, and when I asked for evidence JK's response was 'lets plonk this troll'. 10/10 for developer relations so far?

I still wanted this test for three reasons:

1/ It will turn out that I am wrong and JK is telling me the truth, in which case from now on I develop any code not required on consoles in Java, and save time and development costs. However none of my research leads to this conclusion.

2/ It will turn out unequivocally that Java is not as fast as current game dev methods, in which case Sun might see the light and be motivated to really get there. Eventually I get to drop C++.

3/ The games development group in Sun isn't really serious about games development, in which case they won't want to prove to games developers what they really can do, or will ignore the results of my challenge if it does happen. In this case I resign myself to coding in C++ until someone like Microsoft do get there (and being a more pragmatic and agressive company I'm sure they will).

Actually on a higher level I also wanted to test if Jeff was running an operation genuinely aimed at wooing commercial games developers. The lack of evidence and the way he has treated me answers that, so what am I doing here?  Shocked I've seen and heard enough to not want to waste my time here any longer.

FYI: The Mac does not have a server VM (a documented fact on Apples website), and so runs about 7x slower than C code. You see a similar thing when you compare the client VM to the server VM on Win32. Unless Sun/Apple have a server vm tucked away somewhere, I would say that Java is not ready to support cross platform games.

A.
Offline SpuTTer

Senior Member


Medals: 1


Lazy Middle Class Intellectual


« Reply #42 - Posted 2004-04-18 04:04:05 »

Oh yeah? Well. My dad can beat up your dad.

Sacramento Volleyball
"Whitty phrase goes here."
Offline dleskov

Senior Member


Medals: 10



« Reply #43 - Posted 2004-04-18 08:23:27 »

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Actually thats sort of rhetorical because it doesnt matter either way. As I already explained to Mr. Larder in private, and as you folks all already know, we in the GTG (actually  it wasn't the GTG yet) were at least as disappointed as you folks about the fact that the PS2 VM talks failed to produce results.

We haven't forgotten the importance of this.  It contineus to be a hot button on our list, and we continue to persue avenues to get you guys VMs on consoles.  As I told him.  you guys will be the first to be notified if anything really solid happens but I'm not going to get your hopes up again too early.  Some of us do learn from our experiences.

I cannot believe I am reading this. Did you guys in the GTG ever visit the Sony PS2 Tools and Middleware Web site? It says if you want to create a development tool for PS2, you can sigh an NDA and get a three-year royalty free license to access PS2 development environment and technical information at 1,250,000 Japanese Yen, which is about $12,000.

Now, why cannot you just sign the necessary papers, pay the license fee and port J2SE to PS2 instead of holding all those "talks"and whatever?

Besides, there are three C++ compiler vendors on the list of licensees - Metrowerks, CodePlay and SN Systems.

Offline dleskov

Senior Member


Medals: 10



« Reply #44 - Posted 2004-04-18 08:29:45 »

Regarding the contest, I wonder if you will consider Java natively compiled ahead-of-time, and if yes, do you think it should be playing on the Java side, or the native code side? Smiley

Offline Java Cool Dude

Senior Member




Java forever


« Reply #45 - Posted 2004-04-18 08:52:14 »

If someone provides the physics algorithms for the bouncing capsules, I'll be glad to step forward and take the challenge.
I will use JDK 1.5 and Lwjgl which is a binding to Opengl if it's not kown to some.
Offline philwebster

Senior Newbie





« Reply #46 - Posted 2004-04-18 09:18:45 »

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Regarding the contest, I wonder if you will consider Java natively compiled ahead-of-time, and if yes, do you think it should be playing on the Java side, or the native code side? Smiley

JET doesn't support Mac, so it wouldn't be possible to do the test Andy is suggesting using that compiler.

Does the GNU Java compiler for GCC work on the Mac platform?

I don't have any objections to compiled Java in principle, but I would consider it a third entry, neither 'Java' or 'Native'.
Offline philwebster

Senior Newbie





« Reply #47 - Posted 2004-04-18 09:28:03 »

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1000 $ is 3 months of comfortable live with slight computer updating, and after paing all taxes. I'm not interested.

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It might be interesting to see what will Jeff create in his spare time, but how it would help to game community?

From an advocacy point of view, an experiment which proves that Java is a capable game physics language would be very valuable. If developers are convinced by it, the Java community can grow.

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Worst case would be: Sun engeneers would be somehow distracted from theirs work. And possibly delay few important things.
Best case could be: You actually create something, that would be possibly helpful to the community.

So you claim that capsule (you mean sphere?) bounding in some "cube" will help the community?

There's more to life than code. Knowledge is valuable, and time spent aquiring it is not time wasted. In this particular case, Sun and the Java community will know conclusively whether Java needs improving in a certain area, and if not, Sun gains a nice dataset to assist in their marketing of the language to game developers.

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Perhaps better idea would be. The best hack that would speed up JNI. If there are problems with JNI.

I don't know whether JNI has problems or not. Experiments are a way for us to find out.

Quote

Or why not give that money to person that would finish Java to PS2 compiler?

Because it has not yet been proved that Java is even a suitable game programming language. Let's see how the experiment goes, and then maybe a PS2 porting project can be discussed.
Offline philwebster

Senior Newbie





« Reply #48 - Posted 2004-04-18 09:46:14 »

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Try google or search the forum. You might find a well performing Q3 clone, and some benchmarks against VC with comparable results.

When Jeff first mentioned the FPS, I tried Googling for quite a long time, but nothing turned up. I also searched Full Sail, and even contacted the webmaster. Nothing turned up.

If you know where it is, please post a link. With the amount of effort it takes to write a post telling someone to search for it, you could have at least pasted a reference!

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The odds are that there *could* be a decent java developer out there somewhere outside Jeff, you know Wink Why do you only want to challenge Jeff in person? After all, it's about java's suitability not Jeff's isn't it?

Yes, but it was Jeff that made the original assertion, so it is Jeff who should back up his words with evidence.

People aren't immune from burden-of-proof just because they work at Sun...

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What would be the point of a well performing java (or this whole discussion for that matter) if only 'jeff and his other experts' were able to achieve that?
Why challenge him here in a public community if you don't want that community to be involved?

If some suitably qualified Java game programmers want to step up, let them. At least so we can see how many there are.

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You will prove nothing if jeff won't be involved for whatever reason; it won't prove any of your insinuations about Jeff's integrity that's for sure.

This one is really Andy's argument, but my point of view is that it was really bad form to mouth off about how great Java is and then back off when people asked for evidence. Being sarcastic to respondents wasn't exactly a good idea either. There's no shame in being *wrong* every so often.

If Jeff can't prove any of the things he claimed, he should at least be honest about it and apologise in his next weblog.

But really, this experiment deserves a chance, and it could potentially be quite good publicity for Sun and the Java community as well.

They don't even have to *pay* for it!

Offline dleskov

Senior Member


Medals: 10



« Reply #49 - Posted 2004-04-18 10:26:51 »

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JET doesn't support Mac, so it wouldn't be possible to do the test Andy is suggesting using that compiler.
It makes more sense to run the test on Win32, which was the major desktop gaming platform last time I checked. I think Andy mentioned Win32 as an option.

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I don't have any objections to compiled Java in principle, but I would consider it a third entry, neither 'Java' or 'Native'.
Why so? JET Pro can compile any J2SE program. Classes that may not be compiled ahead-of-time will be compiled just-in-time. So JET Pro is essentially a JVM.

Offline dleskov

Senior Member


Medals: 10



« Reply #50 - Posted 2004-04-18 10:29:59 »

I just recalled that Sun were showcasing JET-compiled Alien Flux in one of their JavaOne booths last year. So JET should play on the Java side. Smiley

Offline philwebster

Senior Newbie





« Reply #51 - Posted 2004-04-18 10:35:29 »

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Well I don't exactly have the chance to take vacation time and fly out to Cupertino (anymore than the next guy I suppose) to check it out personally but then maybe you can?  Strange comment it seems to me.  
Maybe you can just post some kind of quantifiable specs on what you are talking abot here.  Or rather just say what you mean.  What would I see if I went to Cupertino and checked it out?

To be fair, if you read Andy's post he says that you can go down to your own lab *OR* Cupertino. Do you have Macs at Full Sail?


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Regardless, if someone tells me something about some thing, and I say SHOW ME and they can't show me to my approval then I just go about my business.  What is the fire on your belly over this?  If you want to prove something to yourself, write the app.  If you want to prove it can't be done to everyone else write the app.
If you don't BELIEVE it can be done, then really aren't we talking religion and not facts?

In any case, what is your goal?

You have your reasoning back to front here. It is not for Andy to prove that something cannot be done. It is Jeff's responsibility to prove that it CAN, since that is what he has claimed.

Andy's challenge is the 'SHOW ME' that you are describing.

Andy's goal is probably the same as mine: to encourage 'evangelist' types to back up their claims with evidence.

Any academic should know the importance of debate, evidence and peer review. Andy has proposed a sensible method to enable the Java community to demostrate Java's capability without providing get-out clauses whereby participants can make excuses for failure.

If Andy coded the entire thing, there may be claims that Java was not fairly represented. If Java advocates code the Java side, no such claim can be made.
Offline erikd

JGO Ninja


Medals: 16
Projects: 4
Exp: 14 years


Maximumisness


« Reply #52 - Posted 2004-04-18 11:30:01 »

Quote
on Today at 2:13am, erikd wrote:
When Jeff first mentioned the FPS, I tried Googling for quite a long time, but nothing turned up. I also searched Full Sail, and even contacted the webmaster. Nothing turned up.

If you know where it is, please post a link. With the amount of effort it takes to write a post telling someone to search for it, you could have at least pasted a reference!


Fair enough.
Yes, there was some fuzz about that Full Sail FPS and some 3D racer that was demoed here and there but eventually never could be released in public.

You might try here:
http://grexengine.com/sections/externalgames/

There is a well performing FPS there somewhere which loads Q3 maps.
Now I didn't compare Q3 and this FPS so I don't know how well they compare, but I heard it does a pretty good job. And keep in mind it is a one man effort written in a fraction of the time of Q3.

Now back to the challenge, say if the java equivalent would perform, say 10% worse than the C equivalent, would you consider that result to prove that java is still unsuitable for games development?
Where would you draw the line?
Say the C version will perform 2 times better on the physics algorithm, does that make java unsuitable for games programming at all or is it then just slower at physics algorithms?

FWIW, I personally think java nowadays is great for games programming (especially for indies), but maybe not for *all* kinds games. Maybe it would not match up to the kind of game that squeezes every drop of performance out by having some optimized asm here and there or whatever, but those games are a minority. OTOH maybe it would match up, but there's no such game written in java yet.

So on one hand I *am* interested in this challenge, but at the same time I think it should not be a personal vendetta against Jeff but just a technical challenge.

Offline andyl

Senior Newbie




Java games rock!


« Reply #53 - Posted 2004-04-18 12:14:09 »

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It makes more sense to run the test on Win32, which was the major desktop gaming platform last time I checked. I think Andy mentioned Win32 as an option.

Why so? JET Pro can compile any J2SE program. Classes that may not be compiled ahead-of-time will be compiled just-in-time. So JET Pro is essentially a JVM.


Hey dleskov, nice plug by the way  Wink

Although it doesn't fit in with my original challenge to Sun and their JVM, in the interests of gaining knowledge it can play on the Java side, (you will still be limited to pure Java). However the challenge was to prove that Java can match native code performance, for a physics simulation, across the primary platforms Jeff mentioned (Mac OS X and Win32), so you had better get porting your compiler.

If you do have a Mac version, and are willing to throw in $500, great.

And before anyone else gets carried away expecting to use a beta release of the JVM, forget it. You code will have to to be compatible with Apple's 1.4.2 JVM, and the latest release on the PC, which is also 1.4.2_xx. That will be in the rules.
Offline dleskov

Senior Member


Medals: 10



« Reply #54 - Posted 2004-04-18 12:33:01 »

Quote
Although it doesn't fit in with my original challenge to Sun and their JVM, in the interests of gaining knowledge it can play on the Java side, (you will still be limited to pure Java). However the challenge was to prove that Java can match native code performance across the primary platforms Jeff mentioned (Mac OS X and Win32), so you had better get porting your compiler.
Would you let us finish the Linux/x86 port first? Smiley More seriously, we have other targets in mind apart from the Mac.

Then, why should Sun be to blame about poor Java performance on Macs? Apple has licensed J2SE, go tell them to speed it up. Let's compare on platforms that Sun supports (though I doubt there are many Solaris gamers out there. Smiley )

In any case, it would be more interesting to compare on Win32 and PS2, but that brings us back to the major flaw in Jeff's "Java is good for cross-platform game development" statement - the shortage of JVMs for game consoles. C++ programmers caring about portability can get CodeWarrior for Win32, Mac, Linux(multiple CPUs), PS2, GameCube, Palm OS after all...

Quote
If you do have a Mac version, and are willing to throw in $500, great.
We would consider throwing in a JET Pro license. Would that do?

Offline andyl

Senior Newbie




Java games rock!


« Reply #55 - Posted 2004-04-18 12:36:20 »

Perhaps I should explain to those of you who haven't done too much Physics why I chose the type of simulation.

I want it to test the performance of a physics engine. I can't ask all the entrants to write the equivalent of Havok2, so I've chosen a smaller problem that is nice and simple to code whilst still retaining all of the processing that a physics engine would have to do.

The sim would demonstrate:

Collision detection: Capsules are the simplest form of geometric shape I can think of that allows rigid body motion to be demonstrated without friction. I need to be able to put the maths into the rules! (Capsules are like cylinders with rounded ends, rather like some of the pills you take when you are ill). You can simply plug in your own CD engine at a later date if you want to progress the code, everying will still work. Believe me this simple case will still take a bit of coding as you will have to back the simulation up to find the exact time of collision, for each collision in the simulation step.

Collision response: i.e. rigid bodies bouncing off each other.

Numerical integration of the rigid body motion.
Offline andyl

Senior Newbie




Java games rock!


« Reply #56 - Posted 2004-04-18 12:42:34 »

Quote

Would you let us finish the Linux/x86 port first? Smiley More seriously, we have other targets in mind apart from the Mac.

Then, why should Sun be to blame about poor Java performance on Macs? Apple has licensed J2SE, go tell them to speed it up. Let's compare on platforms that Sun supports (though I doubt there are many Solaris gamers out there. Smiley )

In any case, it would be more interesting to compare on Win32 and PS2, but that brings us back to the major flaw in Jeff's "Java is good for cross-platform game development" statement - the shortage of JVMs for game consoles. C++ programmers caring about portability can get CodeWarrior for Win32, Mac, Linux(multiple CPUs), PS2, GameCube, Palm OS after all...

We would consider throwing in a JET Pro license. Would that do?


Jeff finally conceded there are no console VM's, but still asserted that for desktop cross-platform, specifically Win32 and Mac, Java still matches C performance. So the challenge tests that assertion.
Offline erikd

JGO Ninja


Medals: 16
Projects: 4
Exp: 14 years


Maximumisness


« Reply #57 - Posted 2004-04-18 12:59:34 »

Hm, so if it's common knowledge that the Mac JVM doesn't perform as well due to lack of server VM, then there's no point at all in this challenge now is there?
I wouldn't put in my money, that's for sure...

So for argument's sake let's assume you proved the current Mac JVM is not as fast as the Windows, Linux and Solaris JVM's, and so cross-platform games programming has performance issue when it comes to Mac... So now what? Roll Eyes The Mac JVM is likely to catch up, and most of Jeff's points still hold.

Offline andyl

Senior Newbie




Java games rock!


« Reply #58 - Posted 2004-04-18 13:07:41 »

Quote
Hm, so if it's common knowledge that the Mac JVM doesn't perform as well due to lack of server VM, then there's no point at all in this challenge now is there?
I wouldn't put in my money, that's for sure...

So for argument's sake let's assume you proved the current Mac JVM is not as fast as the Windows, Linux and Solaris JVM's, and so cross-platform games programming has performance issue when it comes to Mac... So now what? Roll Eyes The Mac JVM is likely to catch up, and most of Jeff's points still hold.


Err - what like that Java for gaming is cross-platform across Win32 only?

Jeffs blog was about why games developers should be using Java, and given that there are no JVM's on 80% of the target market we should take the Mac and Win32 examples on faith as how good the console versions could be. I'm not impressed with the Mac version, and as Sun licenced it to Apple they should have ensured it also demonstrated the same level of performance that other platform users get.
Offline kevglass

JGO Kernel


Medals: 122
Projects: 23
Exp: 18 years


Coder, Trainee Pixel Artist, Game Reviewer


« Reply #59 - Posted 2004-04-18 13:14:07 »

If you're trying to disprove/prove Jeff's points, don't you think he should be setting the rules and you should be approving them?

If you disagree with any of the rules that would indicate a lack of communication skills in Jeff's blog but maybe it would save us wasting a whole bunch of time (and money?) ..

Ok, back to sleep now..

Kev

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