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Submitted by Charles Bloom, posted on April 17, 2002

Image Description, by Charles Bloom

These images show a little particles system running on an XBox. The particles are time-evolved by the GPU in a vertex shader; that is, the CPU creates particles and then never touches them again. The particles live in memory only once (in the vertex buffer), there is no system memory copy. Particles can be added to this circular buffer by the CPU without stalling the GPU on the XBox.

I get about 30 million particles per second when their size is set to zero, but in practice particle systems are fill-rate limited. As usual, it looks much better in motion, but I'm afraid you need an XBox dev kit to run the demo ;^)

Image of the Day Gallery


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Archive Notice: This thread is old and no longer active. It is here for reference purposes. This thread was created on an older version of the flipcode forums, before the site closed in 2005. Please keep that in mind as you view this thread, as many of the topics and opinions may be outdated.

April 17, 2002, 10:33 AM

Interesting - what language is XBox coding done in? I assume since the XBox is a small computer, that it would be a common language, as opposed to programming ASM for RISC processors. What FPS does the demo get, on the Dev Kit?


April 17, 2002, 10:50 AM

One nice thing about Xbox development is it's easily portable from PC to Xbox considering the architecture is similiar and both use DirectX, therfore using languages like C/C++ and ASM.


April 17, 2002, 10:52 AM

You'd probably use C++, as PS2 games are coded in C++. But I don't know for sure.


April 17, 2002, 10:56 AM

can you use OpenGL with Xbox too?

David Lannan

April 17, 2002, 11:13 AM

Thats pretty neat. How does the GPU look after each particles accel, angle, and fade rate? Looks like some simple algos there but the GPU does all of that? I was under the assumption that Xbox shaders are pretty much GF3 titanium equivalent?


April 17, 2002, 11:28 AM

You can use OpenGL with XBOX, but its not a standard part of the devkit (for obvious reasons, since Microsoft provides the devkit). It is available as a third party middleware solution, though.

To answer the earlier question, most XBOX code is C/C++. x86 assembly is fully supported and often used to hit the SIMD-type instructions, as is also the case with many AAA fast action PC titles. The shaders that run this particle system would likely be written in DirectX's shader language, which is a small assembly language not related to x86 assembly (other than the fact that they are both low-level assemblers).


April 17, 2002, 11:30 AM

Not really sure, but I'm sure it's quite possible some port could exist, figuring that the Xbox platform (from what someone last told me) is a slim w2k platform or another hacked version of windows.


April 17, 2002, 11:32 AM

It will be interesting to see how the XBox will fare. Apparently, developers love it (not a big surprise, its for all purposes a PC, so its familiar grounds, right?), yet the market has not embraced it.

So, as obviously a XBox developer, how do you like it? And that CPU/GPU particle circus you've got going, that's not really XBox-unique stuff, is it?

Sebastian Sylvan

April 17, 2002, 11:37 AM

How the hell?


Ok.. How on earth does this work? What do you need to supply each particle with, pos speed and acceleration or what?

And how does the GPU keep track of where the particle was last step (in order to integrate an additional step)?

Or do you just do pos=vel*t + 0.5*a*t2
with t = curtime - starttime

That would work I suppose...

This is one of the coolest particle systems I've seen.

Christian Henning

April 17, 2002, 11:39 AM

How about a movie, showing the effect? Nevertheless I like it.


April 17, 2002, 11:48 AM

"yet the market has not embraced it."
Ofcource it haven't. You the market want to buy a console they buy a "real" one like PS2 or GC, not a average computer without a keyboard! =)
And besides that Sony and Nintendo have best developers (Capcom, Square etc.)

Too bad that the PS2 is so hard to program (i heard).
And spare me that "X-Box will conquer"-talk. Its just dreams anyway =)

Have fun!

Kurt Miller

April 17, 2002, 11:52 AM

">>You the market want to buy a console they buy a "real" one like PS2 or GC, not a average computer without a keyboard! =)"

So you think they should make an XBox keyboard? ;)


April 17, 2002, 11:53 AM

i totally agree with you Nikkoz ! GameCube will win ! real games !



April 17, 2002, 12:10 PM

Gamecube sucks mayor ass and all the games are really piece of crap :D

PS2 is just.. lame :) well it has good cpu.. but for fuck sake for videogames the rasterizing kit is the main thing..

so.. XBOX is technically the best *console* (its not a fucking pc, grow up) so.. what about the games?
Well.. Halo is already a classic.. AND SEGA makes games for xbox fulltime.. so what the heck.. both the games fun level and quality will rule on xbox :)

gc is a joke.
ps2 is a joke.
dreamcast is dead ;(
xbox rocks


April 17, 2002, 12:14 PM

There is some source code to a particle system that runs on a Geforce 3 completely in GPU on nvidia's deveoper site. it seems to be using verlet integration inside the GPU. It's called explosion or something like that, but can be expanded to other particles effects.


April 17, 2002, 12:15 PM

Love soapy kids


April 17, 2002, 12:17 PM

What third party offers an OpenGL implementation for XBox?

Sebastian Sylvan

April 17, 2002, 12:19 PM

XBOX rules. All the adolescent kiddies are buying PS2 because they don't know what's good for them (brand recognition, also).

I'm NOT impressed at all by GC graphics (and to me, graphics are maybe 50% of the game).

XBOX is the only console, as far as I'm concerned, that's done everything "right". Except for insane pricing but that'll settle down hopefully.
The XBOX is completly superior to anything else on the market.

Halo is the killer app currently. But more games will come. Microsoft has scored quite a few developers.

Jesse Chounard

April 17, 2002, 12:20 PM

That's a great IOTD. I imagine it would look really cool on a big screen TV with the lights off. :)

What's the deal with all the anti-xbox people on this board? There will be plenty of great games on each system. Just play what games you like and shut up about it.

Dan Fekete

April 17, 2002, 12:26 PM

Got to agree with stefan/dxm!
Actually, XBox is NOT a PC! On the other hand, all consoles ARE PCs! Without keyboards. :) Go back in time. Many 8-bit consoles were based on the ZX80 Processor (which was the same in the Spectrum PC). Consoles are based on a Processor and GPU (and some other things but these are the important ones). Just like the PS2 and so do XBox. Just because XBox uses Intel CPU and GeForce (modified) GPU it does not mean it is a PC. But using such a known chipsets actually makes developing for XBox MUCH easier. And it is a MAJOR feature of XBox. What else? Games are incredible, graphics cool, I think we are looking forward a new "King-of-Consoles".



April 17, 2002, 12:37 PM

I am sure XBOX will be a nice dead "king" soon.
Besides all the other "nice" kings which are dead too: OS/2, Beos, etc.
Being feature-rich and powerfull doesn't mean being able to survive.
M$ knows it better, but this time M$'s ass gonna be kicked.

Jason Colman

April 17, 2002, 12:45 PM

You mean Z80.
* wistfully remembers *


April 17, 2002, 12:48 PM

There were indeed some computers from sinclair called like it:
I love my zx-spectrum ;)

Jason Colman

April 17, 2002, 12:57 PM

I love Atic Atac - the game, not you :-)
Anyway the _processor_ is called Z80.


April 17, 2002, 01:13 PM

I have to agree with Jesse on this one. If you don't like a console (or PC) DON'T BUY IT. I for one don't really care if you like it or not. Now as far as facts go you just have to pick who you want to listen to, some say one thing and some say something else. I own N64, Dreamcast, PS2 and X-Box and have had Nintendo, Super-Nintendo and the original Playstation (not the new PSOne) and out of all of them the x-box has the best looking games (Halo, Ralli-Sport), the PS2 has the single most fun game (my opinion GTA3), and the original Nintendo has/had the most games that were all about fun.

Now to the IOTD, this looks good. The upper right reminds me of rose in the After Dark screen saver collection. Running in the GPU seems to me to be a great 'trick'(?). Could you get a lot of other particle effects to work this way? Like smoke, fire or rain?

Sebastian Sylvan

April 17, 2002, 01:15 PM

Tell me this. If the XBOX was developed by another company, and not microsoft, would you still be this negative about it? No you wouldn't. Do you know how I know this? Because you use "M$" when you talk about Microsoft.

You hate microsoft so you can't grasp the fact that the XBOX is superior, developers like it more == more games will be developed for it == market superiority.

It doesn't have brand recognition, so it's got to a bit of a slow start. But it's well on the way.

Patrick 'Gizz' Duquette

April 17, 2002, 01:17 PM

There's already one ( at least for the dev kit )

Dean Nevins

April 17, 2002, 01:27 PM

Nice image. When I saw it I thought of two things, Spirograph and Laserium (I'm dating myself horribly). I kept expecting a cheesy Pink Floyd soundtrack...


April 17, 2002, 01:32 PM

I don't hate or love MS !
I am not negative about XBOX because of MS !
I am negative about xbox because of it's similarities to PC, but
ok all that already said many times here:

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