NVIDIA Shows Interactive Ray Tracing On GPUs 260
MojoKid writes "During SIGGRAPH 2008 in Los Angeles, NVIDIA is demonstrating a fully interactive GPU-based ray tracer. The demo is based purely on NVIDIA GPU technology, and according to NVIDIA the ray tracer shows linear scaling during rendering of a complex, two-million polygon, anti-aliased automotive styling application. The article reproduces screenshots from NVIDIA's demo. At three bounces (rays being traced as they bounce three times through a scene), performance is demonstrated at up to 30fps at HD resolutions of 1920x1080 for an image-based lighting paint shader, ray-traced shadows, reflections and refractions running on four next-generation Quadro GPUs in an NVIDIA Quadro Plex 2100 D4 Visual Computing System." Meanwhile reader arcticstoat passes on Intel's latest claim that rasterisation will die out the next few years, possibly in favour of ray tracing.
Beautiful (Score:5, Interesting)
Wow, those screen caps are gorgeous. I hope this finally puts to rest the idea that rasterizing with upteenth number of features added in can compete with the image quality of Raytracing. While rasterizing may have a number of competitive features, it's hard to get the same level of specularity, reflection, shadows, shading, and other features so nicely demonstrated by this demo.
The genius of what NVidia is doing here, I think, is that by using their existing GPU architecture, they create a path by which Raytracing can be phased in as a technology without removing the support and investment in current rendering pipelines. This is a bit different from Intel's goal, which appears to be a cutoff between the old and the new.
Another interesting point is that this demo is currently capped at 3 casts per pixel. Which means that the scenes shown could look even better than they already do. Shadows could be softer, reflections could be more complex, and inventive scenes could be created to make for interesting styles of gameplay. (e.g. Fighting in a hall of mirrors.) If 3 casts/pixel is the baseline, then NVidia is setting up a vast new territory for graphical improvements. Each increase in casts/pixel will increase the realism of the scene. Thus graphical quality becomes a matter of raw horsepower. A market that I'm sure NVidia would gladly be interested in opening up.
Funny how things change, eh? [slashdot.org] :-P
Actually, I doubt NVidia has changed its position by very much. They're probably making a smart business decision and ensuring that they ride the wave of Intel's hype. If Intel *does* succeed in convincing the market that Raytracing is the future, NVidia will be ready to compete rather than cede the market.
Re:Beautiful (Score:5, Interesting)
They're probably making a smart business decision and ensuring that they ride the wave of Intel's hype. If Intel *does* succeed in convincing the market that Raytracing is the future, NVidia will be ready to compete rather than cede the market.
It's great for nVidia that they can do this with their chips, but I don't think this was done primarily for tech purposes. I think you're close to the truth when you say they can ride Intel's hype, but not quite spot on. I think this is meant to break Intel's growing ray tracing hype machine, not come along for the ride.
"Look, we can do now what you say you'll do in two years, and we can do it WAY better than you will be able to then, but on our current tech."
I can't imagine anything could be more effective at ending the "Intel will crush nVidia with ray tracing" meme that's been affecting nV stock.
Re:Beautiful (Score:3, Interesting)
"Another interesting point is that this demo is currently capped at 3 casts per pixel."
You mean three bounces per pixel.
Also, from TFA:
"running on four next-generation Quadro GPUs in an NVIDIA Quadro Plex 2100 D4 Visual Computing System"
Sure this is impressive, but they are pushing kilowatts to get this kind of performance.
Re:Beautiful (Score:5, Interesting)
They are gorgeous? Really? I think they look distinctly average. The lighting calculations look very simplistic. Yes, the shadows and reflections may be pixel perfect, but that just doesn't matter that much. You usually can't tell they are anyway. The same scene rasterized with a simple cube map for the car's reflection and some proper shadow maps would look much better. Not to mention run faster.
And "graphical quality becomes a matter of raw horsepower"? This unlike in rasterization then?
Not quite yet, I'm affraid (Score:4, Interesting)
Actually, I think that the biggest problem with animated porn isn't texturing-vs-raytracing, but the models and animations. Last time I ran into some adult Poser-fu, it looked all wrong in a massively uncanny-valley way, and not because of the texturing.
And with the animations, well, I'd assume it's actually easier and cheaper to find a gal who'll bounce on a cock for half an hour for a few (thousand) bucks, than a highly skilled artist and animator who'll make that look natural.
Plus, raytracing is IMHO entirely the wrong secret sauce there. Ray tracing works best for sharp, metallic/mirror reflections. Because then you can take each ray and reflect it as one ray. If you want to go diffuse, that's a lot more expensive with ray-tracing. Then you need to split each ray into sub-rays that reflect into slightly different directions from there. Same as anti-aliasing is done by calculating sub-pixels, basically.
I.e., ray tracing looks grrreat and is the cheapest for shiny cars, crystal cups, and the like. Which is why everyone ray-traces cars and the like. It sucks for something like human skin, unless, of course, you want to make those humans look like polished shiny plastic dolls.
So, well, I can't imagine that much need for it in porn at the moment. Unless, of course, you want to make a Transformers sex movie. Or maybe one with liquid- metal Terminators fucking. (Hey, they must have made some female versions too, right?;)
Re:Beautiful (Score:5, Interesting)
Yes, and amusingly reflection and refraction (two of the main benefits of ray tracing) are a couple of things that humans generally can't tell if are being fudged. As long as it's in the ballpark it's enough to fool the human eye. Pixel perfection is way beyond what's required.
What does that mean? Capped?
Why? Details please. What exactly is more realistic about tracing each pixel through the geometry than drawing the geometry directly in the appropriate pixels? The underlying lighting calculations are the same either way, meaning they will both look the same, so the only real concern is speed for any given scene.
So if we look at speed ray tracing only has a real benefit in reflection and refraction, but that's not really a winning argument because, as I said, people can't really tell if it's 100% accurate anyway. I sure can't. Ray tracing can also do accurate soft shadows relatively easily, but the ray count required makes that completely unrealistic in real time for the foreseeable future. Shadow maps will be faster either way, and look 99% as good.
Ray tracing is simple to implement, but so is cracking a password using brute force. That doesn't make it the best solution.
I, for one, welcome our ray traced overlords (Score:4, Interesting)
Re:Beautiful (Score:3, Interesting)
Yet in the case of Raytracing, "efficient enough to be feasible" means real shadowing, not the shadow-map crud we see in most video games.
I can and I will. Shadow maps used in games like Crysis beat you over the head with depth perspective. i.e. "Look, there's a shadow! Now you know how far off the ground the helicopter is!" While that's nice and all, only the objects that you map and define to have shadows actually cast a shadow. The subtle interactions of the environment and the actors are usually lost. It's almost like someone took a bunch of stage props, covered a stage with styrofoam sand, then threw all the props on top. Thus the actors stand out from their environment.
With ray tracing, the shadows are correct. Period. If a monster picked up that NVidia car and threw it through the air end over end, you'd see all kinds of shadow interactions happening that simply won't be visible on a shadow-mapped engine like Crysis.
Heck, you don't even have to get that complex. The car casts shadows upon itself. Which already makes it look more realistic on a closeup than anything an existing game engine can do [bit-tech.net].
In addition, ray tracing can scale a hell of a lot farther when it comes to realistic lighting and shading. With more rays not only comes softer shadows, but multiple shadows, reflective surfaces, and other "realistic" shadowing techniques that can't be touched by today's shadow map engines.
Re:Beautiful (Score:3, Interesting)
That's nothing. Cell can raytrace a whole city! (Score:5, Interesting)
Speaking of Ray Tracing...
Check out this video showed at SIGGRAPH this week of the University of Virginia Rome model being ray traced in real time by a Cell Blade:
http://www.youtube.com/watch?v=YZnbMWy9A0Y
Nifty!
The one thing I want (Score:3, Interesting)
> But reality is that several best games I have played were ... 2D.
Damn right. And you know what capability I would really like to have on a card? Masked blit. That is the single most time-consuming operation on all 2D games. If you could copy all your tiles to the video card memory and then maskblit them onto the visible page (or blit and flip if it's too slow), that would really make 2D games smooth as silk and leave more CPU power for AI and real gameplay.