RPU to allow realtime ray tracing

[theotherguy]

paraphrased from scientific american magazine:

In 2003, Saarland spun off a company to commericialize real time ray tracing technology. They founded inTrace, using first-generation software that required a cluster of high-powered servers to render full-resolution, photorealistic images at 10 frames per second or higher....

meanwhile, since then their raytracing algorithms have grown advanced enough to allow real-time processing on consumer PCs.

Unlike classic ray-tracing programs, Saarland's algorithm divides multiple beams of light into similar "packets" which all run on the same thread, the packets are then processed on a device called an RPU, which can process about twelve threads at a time, so whereas normal ray tracing programs can only trace one ray per cylce, there's is able to trace anywhere from 60-100 rays per cycle.

Aditionally, the algorithm divides a scene into leafs of equal cost, and computes each leaf in such a manner that is most efficient, doing the most costly leafs first and then doing the less costly ones.

The RPU is an early prototype running at only 66 Mhz, yet it outpreforms every other processer on the market in ray tracing. Saarland hopes to produce a final prototype with 50 times the power, which should be easily able to churn out commercial-quality ray tracing at 60 frames per second.

For example, Saarland had their team construct an entire island, 40 million polygons, complete with refracting water and volumetric clouds, and then raytraced the entire scene on an RPU (note that it was a tiny, first generation prototype at 66mhz) at 12-15 frames per second.

This will allow all kinds of advances. First of all, each frame of a game will only need one rendering pass, improving performance dramatically and making it much easier to create things like shaders. Second, animated movies, like those made by pixar, will be able to be rendered much faster, and thus cheaper. It's even possible that pixar movies will eventually be rendered in realtime. Third, 3d modellers will now be able to edit a rendered scene in real time.

So basically Saarland is planning on producing an expansion card, similar to the PPU, which would be based only on ray tracing. So ideally, PCs of the future will use CPUs for AI and overall game calculations, a PPU for physics, an RPU for ray tracing, and a GPU for antialiasing, after-effects and conventional shaders.

This is a scene that was rendered in real time by the RPU in siggraph 2005. Again, note that it is an extremely early prototype, and that the commercial version of the RPU will be able to handle scenes 50 to 100 times more complicated, meaning we should be seeing real-time lighting like this in the very near future.

EDIT: I found some more recent images as well as a few videos:
A boeing 737 rendered in real time

A video showing an office scene
note that it is only running at 3 FPS, which is considerably better than conventional renderers, which could take minutes to render the scene. With improvements to the RPU it won't be long before we have this scene running at 60 FPS.

 

[The Brick]

Great.. another add-on card. It does sound promising though. I'm eager to see what that thing can do. If it indeed looks realistic. I believe that this thing was showcased somewhere, but I can't remember where that was.

Btw, I'm sure an AIPU will be developed someday.

 

[Icarusintel]

Ray Tracing... in my computer? Holy f*cking shit, yes! Wow, this i awesome news, though I'm definitely gonna need to switch to liquid cooling if I'm gonna have a CPU, 2x GPU, PPU, and an RPU all running together.

Still, this seems to be the right direction towards getting truly photorealistic games.

 

[The Brick]

For example, Saarland had their team construct an entire island, 40 million polygons, complete with refracting water and volumetric clouds, and then raytraced the entire scene on an RPU (note that it was a tiny, first generation prototype at 66mhz) at 12-15 frames per second.

A video showing an office scene
note that it is only running at 3 FPS

:|

 

[Cole]

Real Time Tracing is f*cking insane.

 

[theotherguy]

:|

I just realized that the video I posted is not using an RPU, its just using their software on a single threaded computer. This is why the island scene ran much faster.

But in any case, considering it can take anywhere from one to five minutes to render that many polygons in a traditional sense, I'd say its a massive improvement.

EDIT: in fact they posted that video to show another piece of software, OpenRT, which aimed for realtime raytracing on conventional CPUs

 

[Asus]

Thats awesome. You'd get correct reflections and lighting.
Doesn't ray tracing performance scale better with more and more detail in the scene compared to the way typical graphic cards render? I thought I read that somewhere. Although we are still a ways off from typical graphic cards hitting their limit.

 

[The Brick]

Maybe we'll be seeing this sort of stuff in realtime.
http://graphics.ucsd.edu/~henrik/animations/jensen-the_light_of_mies_small.avi
Note that this animation has nothing to do with the RPU.

 

[Asus]

I remember seeing that video before. That is neat.

 

[JNightshade]

Ooh, that's cool!

 

[theotherguy]

yes, sadly the RPU doesn't yet support global illumination, only direct lumination ;( . OpenRT does indeed support global illumination, but with it enabled it woudl take a monstrous amount of processing power to run at speeds higher than 20 FPS (I think they said to get it to run at a playabe framerate they had to cross-link 48 PCs)

However, the RPU is getting very near that territory. Currently it would need to be about three times as powerful to adequately simulate global illumination, and for that matter, soft shadows. (but getting it three times as powerful should not be much an issue, it only runs at 66 Mhz with 36MB of ram)

I do admit though, the more I look into this the more dissapointed I am. I think that the article was very misleading at the quality of the ratracing preformed. However, the RPU does run much better than OpenRT on conventional CPUs, which is pretty promising.

 

[Reaktor4]

EDIT: I found some more recent images as well as a few videos:
A boeing 737 rendered in real time

A video showing an office scene
note that it is only running at 3 FPS, which is considerably better than conventional renderers, which could take minutes to render the scene. With improvements to the RPU it won't be long before we have this scene running at 60 FPS.

They dont look very realistic..

Maybe we'll be seeing this sort of stuff in realtime.
http://graphics.ucsd.edu/~henrik/ani...mies_small.avi
Note that this animation has nothing to do with the RPU.

Very nice.

 

[Ren.182]

Sounds cool. Bet it'd look cool too

But can't they just stick these on the graphics cards? :/

 

[theotherguy]

yes, but it would require adding multiple cores to the GPU, completley reworking the GPU and adapting the card, at which point you basically have a new card anyway. What I can see happening is a second processing unit being put on the graphics card, so that it has dual functionality. There is also talk of using quad-core CPU's, but it would detract from other CPU activities.

 

[Asus]

I'll just buy 2 quad core boxes to use as my fancy ray tracing 'card' and have em connected to my computer.