3D Raytracing Chip Shown at CeBIT

An anonymous reader submits "As noted at heise.de Saarland University is showing a prototype of a 3D Raytracing Card at CeBIT2005. The FPGA is clocked at 90 MHz and is 3-5 times faster in raytracing then a Pentium4 CPU with 30 times more MHz. Besides game engines using raytracing there was a scene of a Boeing with 350 million polygons rendered in realtime."

Comments

90 mHz...

[Geogriffith]

90mHz chip that can raytrace far more efficiently than a p4... I want to overclock this thing SO bad!

Open FPGA?

[Doc Ruby]

Is the SU driver open source? Because it would be fun to see people hacking it to send general purpose netlists to the FPGA, and harnessing it for other HW-accelerated tasks. Maybe loading up all the PCI slots with those boards, pooling the GFLOPS, and tapping them for graphics when needed - leaving the rest for computation.

Re:Open FPGA?

[harrkev]

And if every PC since 1990 has a FPGA in it, we would be stuck with backward-compatability problems. "I have the new Vertex 2 Pro. Too bad it can't run my game, which requires an original Vertex."

This is a major problem. A modern processor can abstract away many of the complexities of its design. The ISA just has to run, and the processor can handle the details of how this happens. With an FPGA, you are down-n-dirty with the hardware. Any architectural changes have an major impact on how you handle the device.

If you want software to take advantage of a FPGA, then you have to have a standard. Let's assume that an FPGA is chosen as the "standard." Here are the consequences:

1) You now have one vendor -- who can arbitrarily set their own prices. FPGAs have a lot of IP in them, so one manufacturer cannot simply copy another's design.

2) Upgrading would be very difficult, because you would loose backwards-compatability.

3) How do you handle multi-tasking? What if you have two programs running - both of which need the FPGA?

4) Bad code. It is easy to imagine a scan chain sending one "one" followed by a bunch of zeros. Then, tie all of the drivers to the same global net. Every clock tick = a blown transistor! Fun task for a virus writer!

I am not saying that having an FPGA is a bad idea, but you need to think long and hard before you do this. You would need some sort of API for the FPGA. Obviously, hard-coding for one FPGA will not work. We need flexibility. So, we need to be able to compile for an EDIF, with the ability to use cores. And going through this process once can take HOURS on even the fastest of machines. "Thank you for installing Photoshop 2008. We are now going to prepare the FPGA programming. Please wait 12 hours." This would only need to be done once per machine, but would still be a pain in the rear.

I can see that the FPGA is needed in certain circumstances, but I doubt that it is a good general-purpose device.

Re:Hardware encoding

[ghereheade]

As an FPGA, no. NVIDIA et al would find it to expensive. But if they can roll their Verilog/VHDL code into an ASIC without to much trouble, it might be cost effective enough to catch the gamer and CAD markets. And as a side benefit, an ASIC should potentially run even faster thus giving even more amazing performance. In fact, without knowing what these guys are up to, I'd bet that is in their business plan.

Performance

[MatthewNewberg]

On the Ray Traced Quake 3 Website it says that runs faster with more computers (about 20 fps@36 GHz in 512x512 with 4xFSAA)

Assuming that is correct,a normal chip can render Ray Traced Quake 3 like graphics at 2 to 3 fps on a 4GHZ machine which means the Ray Tracing Chip could do it at 6 to 9 fps. This might be real-time for alot of research, but when it comes to games anything less then 15 fps is a joke. I'll be interested when they can hit 30 fps, with more graphics complexity then Quake 3.

Re:Performance

[timeOday]

It seems like raytracing would be ridiculously easy to run in parallel. If they're only 90 mhz chips, they probably don't take much power anyways. They should slap 8 of them on a board.

The "Q3RT" screenshots...

[Lisandro]

... are impressive (here and here, for example). They don't look like much and might appear a bit dull but the ammount of details in reflections and such is surprising.
Call me a kid, but this amazing technology appears and all i can think is how cool would it be to see enemies coming behind you reflected in a sphere...

Too bad there's no video - but then again, the poor server is doing bad enough as it is.

Research not meant to be immediately practical

[Goonie]

Look, if it was production-ready, it wouldn't be research.

While it's certainly not enough to start playing games, it's a heck of a lot closer than I thought was possible. And there's a lot of tweaking that could be done to speed the process up with present technology. An FPGA is the integrated circuit equivalent of a stack of lego. It makes it possible to build custom hardware without forking out for a custom chip; they are however much slower than such a custom-built. I expect if Nvidia decided to make their next-generation chip a raytracer they could get your 30fps. They won't do that for a while yet though - 512x512 is a long way off the resolution gamers currently play in.

But this is interesting, even though it's not practical yet, because it puts the idea on the table that, in the not too distant future, real-time raytracing might well be a possibility. From here, the big graphics-chip makers can start seriously thinking about it, and, maybe about 5 years from now the first hardware raytracers will begin to appear in 3D graphics cards.

Re:Hardware encoding

[Anonymous Coward]

Ray tracing and the current OpenGL/Direct3D way of rendering images are completely different. With OpenGL the rendering system renders a polygon to the frame/z buffer and can pretty much forget about its existance from that point on, meaning reduced memory overheads. Raytracing on the other hand requires every object in the scene to be accessible to render any pixel, each pixel "ray" needs to be tested against all objects in the scene to see which one it hits. This also causes problems moving from the current way programs send polygons to OpenGL to the way required for Raytracers, as I said earlier OpenGL can render and forget, whereas a raytracer can't.

Once those problems have somehow been solved (I don't like the thought of storing 100+million triangles+textures+material info in a video cards memory) then raytracing provides some nice benefits, like parallel rendering - each pixel can be rendered completely independant of any other pixel. Running at 1024x768 could possibly make use of 1024x768 raytracing chips running in parallel! The actual process of raytracing is fairly simple and very elegant (zero overdraw and reflections that can be implemented in a couple of lines of code on a suitable raytracing design), which to me means it is a better solution than all the hacks required to make OpenGL style rendering work. I'm not saying OpenGL is bad, in fact its amazing what can be done with current rendering techniques, but those techniques have come about largely as ways around the problems created by a sub-optimal process which was designed as a way to get around having to keep everything in memory.

I seriously thought PS2/Emotion engine wud do this

[cheekyboy]

When the magic emotion engine of ps2 was announced, I thought, hmmm are they going to for once try realtime raytracing in hardware or cont with tired old polygon rendering.

Imagine if nvidia threw in an extra 5m transistors for a raytracing option ;)

why not old crap pcs are clusters

[cheekyboy]

Why not gather up some old crap PCs, 1ghz or 1.8s, build a stack of 10-20 of them ($299 * 10) and install linux/povray on em all or whatever you use.

Hell, even 20 chipped xboxs ;)

raytracing advantages

[bani]

afaik the advantage of raytracing is that you are no longer bound by polys though. you can easily have unbelievably complex scenes with little performance impact vs simple scenes. your bottleneck is no longer polys/sec but now rays/sec.

and iirc raytracing is a very simple thing to parallelize. given the performance they are getting out of their FPGA prototype, I expect this will scale nicely.

imo raytacing is the obvious future of graphics cards.

as an aside, a lot of game mechanics is dependent on raytraces for detecting collisions. now if you could use a raytracing GPU to handle that as well, you've offloaded yet more work from the CPU... :-)

PS5, Xbox Next II?

[KrackHouse]

I wonder if they're thinking ahead enough to consider a combination of the new Physx chip with a few of these things on a multicore chip. George Lucas just merged his game and movie production studios, seems to be a real trend.

HQ RT Ray Tracing

[SnprBoB86]

As interesting and promising as this is, it is currently useless because it seems to produce low quality renders.

The screenshots on the site all show images that could easily be rendered with much greater quality and efficiancy using shadow maps or stencil shadows and manual matrix transformations with portal rendering for reflections.

When this hardware can render scenes on par with that of a professional software ray tracer in real time, then there will be some serious consumer demand.

Re:Do you know what an FPGA is?

[Mortlath]

Hmm, I assumed that they had used a FPGA because it was only their prototype board.

From what I've learned in one of my digitial system design courses from college, ASIC have an upfront production cost of $1,000,000 to $2,000,000 and a small unit price, while FPGAs have a much lower fixed cost (~ $10/unit).

So, I imagine they will manufacturer ASIC chips when they get a big sponser, unless they are using the FPGAs dynamic abilities...

Re:Hardware encoding

[Rothron the Wise]

Of course, raytracing produces beautiful results compared to the other methods of 3d graphics, but it is MUCH more expensive in terms of CPU cycles on today's CPUs

This may not be true for very long. The complexity of a scene in a traditional polygon renderer like nvidia's chips scales fairly linearly with the number of polygons in view. Not so with raytracers. They have hierarchical structures to test for which group of triagles a ray may intersect and scales more like O(n log n). They also render _only_ viewable pixels, while overdraw is a major hurdle for traditional 3d cards.

What this means is that as scenes get increasingly more complex, there is a crossover point where ray-tracing will overtake traditional rendering, and dedicated raytracing hardware ensures that this happens sooner. If you add this to the fact that raytracing lets you have perfectly smooth non-polygonized objects, perfect reflections and other features not easilly replicated by traditional rendering you'll see the incentive.

A case in point: prman, the renderer used by Pixar is a traditional polygon rasterizer, but Pixar has on occation used BMRT (A renderman compliant ray-tracer) for scenes that require ray-tracing for realism.

Specifically a scene in A bug's life depicting a glass bottle filled with nuts was renedered using BMRT. Flexible and robust realistic reflection and refraction is solely in the domain of ray tracing. What you saw in Half Life was only cheap tricks which would fail miserably in less constrained scenes.

Programer vs. Artist screenshots.

[Lerc]

So many people are dismissing ray tracing out of hand because the screenshots are not as pretty as some from the latest games.

Let me ask you. Why would you expect teams of electrical engineers/mathematicians/programmers be able to produce a prettier image than a team of extremely talented artists.

The job of the artist is to make it look pretty. The job of the guys making this chip is to provide features and to make it go fast.

So it's not fast enough yet. It's a prototype. When it can render decent resolutions at decent framerates then bring in the artists and see what they can do with it.

Re:Sweet deal!

[Anonymous Coward]

The cool thing about ray tracing which you've failed to realize is that while you might need to cast 3.2 million rays, that is a FIXED number! If you have an empty room or a room with 1 trillion pollygons (that's way, way, less than doom 3 by the way), it will still take 3.2 million rays to render. So essentially, it will take the same amount of time to render regardless of scene complexity (this is of course a *major* simplification, it's technically log(n), but this is essentially constant).

Raster based rendering, like what is used for doom3 with a GPU, is VERY dependant on number of polygons, so as you increase the number of polygons, game will noticably slow down.

So if you want to have games with tons of polygons, ray tracing wins out over raster based rendering. And I think we would all agree that more polys is better :)

Re:Duh, you develop with FPGA. Then you make ASIC.

[Kiryat Malachi]

Reconfigurable hardware is rarely enough of a benefit to outweigh the large cost differential between an ASIC and an FPGA.

(I work for an ASIC design team for a living, so yes, I do know what I'm talking about.)