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NVIDIA Shows Interactive Ray Tracing On GPUs 260

Posted by kdawson
from the raster-fair dept.
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.
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NVIDIA Shows Interactive Ray Tracing On GPUs

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  • Beautiful (Score:5, Interesting)

    by AKAImBatman (238306) * <akaimbatman@NosPAm.gmail.com> on Friday August 15, 2008 @11:00AM (#24615527) Homepage Journal

    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)

      by Colonel Korn (1258968) on Friday August 15, 2008 @11:10AM (#24615693)

      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.

    • by qoncept (599709) on Friday August 15, 2008 @11:10AM (#24615707) Homepage
      I suppose, but that guy could certainly use some tire-wet. Those sidewalls look awful.
      • Re:Beautiful (Score:5, Insightful)

        by Austerity Empowers (669817) on Friday August 15, 2008 @11:45AM (#24616287)

        I think if you look closely you'll see that they used materials very sparingly. The man behind the curtain (IMO) is that they're dedicating all their GPU and memory bandwidth to ray tracing computations, at the expensive of traditional raster manipulations.

        Who cares? Well, I think if you're playing a game where you are free to run where you like, you may care.

        I agree, nVidia is showing that ray tracing doesn't scare them at all. And when it's ready to happen, it will. I disagree that it's ready to happen any day now.

    • Re: (Score:3, Interesting)

      by WilyCoder (736280)

      "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, Informative)

        by mypalmike (454265) on Friday August 15, 2008 @11:25AM (#24615947) Homepage

        Every bounce casts a new ray, so "3 casts per pixel" is an accurate description.

      • Re:Beautiful (Score:4, Insightful)

        by Enderandrew (866215) <enderandrew.gmail@com> on Friday August 15, 2008 @11:33AM (#24616055) Homepage Journal

        Intel's last demo was running on 8 GPUs wasn't it? On those were GPUs designed for ray tracing I thought.

        I like Nvidia's approach to use existing architecture, and I agree with the poster above who says this is a much better method for consumers.

        I disagree however with Intel saying rasterization is dying any time soon. Intel and Nvidia can't produce these effects with reasonably priced hardware, and even when the hardware becomes affordable, we still need games designed for this, and then a few years for the technology to be accepted by the masses.

        I say rasterization sticks around 3-5 years.

        • Re:Beautiful (Score:4, Informative)

          by robthebloke (1308483) on Friday August 15, 2008 @01:32PM (#24618035)
          I say rasterization sticks around 3-5 years.

          I used to hear exactly the same things being said by the ray-tracing evangelists in the FilmFX industry 15 years ago. Rasterization is still the primary techinique used for any film you care to mention, and I'm almost 100% certain it will still be the primary technique 30 years from now.
    • Re:Beautiful (Score:5, Interesting)

      by hr.wien (986516) on Friday August 15, 2008 @11:14AM (#24615765)

      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?

      • Re:Beautiful (Score:4, Informative)

        by AKAImBatman (238306) * <akaimbatman@NosPAm.gmail.com> on Friday August 15, 2008 @11:23AM (#24615911) Homepage Journal

        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.

        Sure you can. A human instinctively knows when something looks "right" or "wrong". And one of the reasons why rasterization is capped is due to lighting problems. Lighting technology has improved significantly in the last decade, but still not sufficiently to compete with raytracing. Raytraced lighting will look more natural to an untrained viewer.

        And "graphical quality becomes a matter of raw horsepower"? This unlike in rasterization then?

        Rasterization is heavy on hardware features to improve the quality and performance of the scene render. e.g. Blending, pixel shaders, z-buffers, etc. Ray tracing is a far simpler operation on the hardware side, though it still behooves the software side to improve the number of objects tested for rendering. (Nothing new there.)

        • Re:Beautiful (Score:5, Interesting)

          by hr.wien (986516) on Friday August 15, 2008 @11:42AM (#24616229)

          Sure you can. A human instinctively knows when something looks "right" or "wrong".

          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.

          And one of the reasons why rasterization is capped is due to lighting problems.

          What does that mean? Capped?

          Lighting technology has improved significantly in the last decade, but still not sufficiently to compete with raytracing. Raytraced lighting will look more natural to an untrained viewer.

          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.

          • by jacquesm (154384)

            I think you're missing the shadows bit completely, and they make a *HUGE* difference in what is intuitively right and what is definitely computer generated. I have a hard time with some ray traced images to tell them from the real thing (usually they're just a bit too perfect), but rasterization, no matter how well done feels 'wrong' right away.

            Raytracing simply comes much closer to how things actually work and so has a much better chance of appearing natural.

            Once things start moving those differences reduc

            • Re: (Score:3, Insightful)

              by hr.wien (986516)

              The reason ray traced images often look very realistic isn't because they're ray traced, but rather because they are done offline and as such can take ages to do the calculations required for a realistic lighting model. What can be done given enough time doesn't matter. What is efficient enough to be feasible real time is.

              Raytracing may be "closer to simulation", but that's completely irrelevant when the performance isn't there for the quality of the output. Can you honestly tell me you think the shadows in

              • by jacquesm (154384)

                I think the answer is yes, take a look at the mirror in the green car demo shot (bottom right, at high res), that's a pretty impressive following of the contours of the car by the shadow, a 'straight' computed shadow would never ever do that, compare this shot:

                http://www.gamershell.com/static/screenshots/9451/264393_full.jpg [gamershell.com]

                from crysis, where the shed shadow meets the terrain contour.

                That's exactly the kind of thing I meant.

                • by hr.wien (986516)

                  The same scene using shadow maps would look more or less the same, but in addition you would have compute power left to actually make the shadow fuzzy like it is in real life. The hard shadows you get in ray tracing without sufficient light traces look anything but realistic. Especially in outdoor scenes.

                  I'm not sure I understand what you mean about the Crysis pic though. Looks fine to me?

                  • by jacquesm (154384)

                    I think the fact that it looks fine to you is more or less where the problem lies :)

                    The contour of the shadow of the shed looks completely unnatural to me (not to mention very poorly anti-aliased). I wouldn't bitch about it too much though, because for one it's a game and it was generated on the fly by hardware not to be compared to that of TFA.

                    Sure, if you spent as much time as you wanted on that image using the very best of the rasterization algorithms without any optimizations for performance that would

                    • by hr.wien (986516)

                      I think the fact that it looks fine to you is more or less where the problem lies :)

                      Okay then, please humour me. Which general area of the picture should I be looking at? There's a lot of shed.

                      The only way to really tell is to take the exact same scene and lighting model, run both algorithms, then compare the results side by side, and in those comparisions, ray tracing wins hands down, at the expense of a vast increase in computing resources used.

                      Whoo there. That depends highly on the scene in question now

                    • Re: (Score:2, Insightful)

                      by robthebloke (1308483)
                      The only way to really tell is to take the exact same scene and lighting model, run both algorithms, then compare the results side by side, and in those comparisions, ray tracing wins hands down....

                      When rendered at 60fps in a fast paced car game, are you going to ever notice those minute details? Would you even care?

                      For the record, I think the quality of the images are pretty poor. Just look underneath the car at the back wheels (pic bottom left). The shadow colour is uniform, there's no texture, no
                    • Re: (Score:3, Insightful)

                      by jacquesm (154384)

                      the low shed central in the picture

                      the 'reflecting ball on the checkerboard' is a technology demo to show basic principles, it's not a realistic scene.

                      In a realistic scene *everything* has a shadow, and every bit of the image interacts with almost every other, making the 'model' (if there is such a thing) a one off for every camera viewpoint and for every object movement. There is no way that you're going to make your model that complicated for a rasterizer. A ray-tracer sidesteps that model complexity issu

                    • Re:Beautiful (Score:4, Insightful)

                      by jacquesm (154384) <j&ww,com> on Friday August 15, 2008 @01:35PM (#24618087) Homepage

                      From what I understood (correct me if I'm wrong!), the movie 'cars' was actually done using a ray tracer, which for pixar was a first.

                      As for the comments wrt picture quality, yes, I agree with all the comments, but there is some stuff there that would be pretty hard to copy with a rasterizer, and I would expect the quality to dramatically improve if/when they decide to pursue this further.

                      The impressive thing is not really how well the pig dances, at this stage the impressive thing is that the pig dances at all.

                    • Re: (Score:3, Informative)

                      by hr.wien (986516)

                      As an example, a field of grass would need a shadow map for every blade

                      No, no, no. You have one shadow map per light source in most implementations (or a cube map for a point light. Depends on the algorithm used). You render the scene (depth only) from the light's viewpoint into this texture, thus finding the world space coordinate of the front most geometry (the shadow casters). Then, when you render from the camera viewpoint you look up each pixel's world space coordinate in this texture to determine if i

              • Re: (Score:3, Interesting)

                by AKAImBatman (238306) *

                What is efficient enough to be feasible real time is.

                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.

                Can you honestly tell me you think the shadows in Nvidia's demo look better than the ones in, say, Crysis?

                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,

                • by hr.wien (986516)

                  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.

                  Bullshit. Crysis has self shadowing, just like any other moderately recent game. The screenshot you posted is in one of the lower quality modes in which it may be disabled.

                  Crysis also has shadows from a number of light sources simultaneously, but the number is limited (4 IIRC) for performance/quality reasons. I suggest you look

                  • Bullshit.

                    Back 'atcha.

                    Crysis has self shadowing, just like any other moderately recent game. The screenshot you posted is in one of the lower quality modes in which it may be disabled.

                    It's not disabled. Look at the upper right corner of the ship, just to the left of the right wing. You will see a minor shadow cast by the ship onto the ship. Look at the superstructure to the left. The overhang is casting a shadow onto the lower part of the tower.

                    Both look like crap.

                    Crysis also has shadows from a number of lig

                    • by hr.wien (986516)

                      It's not disabled. Look at the upper right corner of the ship, just to the left of the right wing. You will see a minor shadow cast by the ship onto the ship. Look at the superstructure to the left. The overhang is casting a shadow onto the lower part of the tower. Both look like crap.

                      Ah, so when you said game engines can't do it, you really meant they can, it just doesn't look very good?

                      Well, that is purely down to shadow map resolution and power limitations in the filtering of them. You'd hit the similar

                    • by hr.wien (986516)

                      you really meant they can, it just doesn't look very good?

                      Meh, going back to your original post I seem to have misinterpreted your statement the first time around. That was in fact all you said. My apologies. My point still stands though. For the quality, shadow maps are more efficient, hence yield more realistic results in real time.

                    • Ah, so when you said game engines can't do it, you really meant they can, it just doesn't look very good?

                      Well... more or less. :-P

                      More specifically, I mean that they can't internally shadow the way you'd expect real objects to shadow. When a soldier moves his leg far forward during a sneaky walk, you don't see a shadow of his weapon and arm cover his leg. That is realistic internal shadows. Placing shadows on obvious overhangs is just more beating the player over the head with depth perspective.

                      Not to say t

        • by Spatial (1235392)

          Raytraced lighting will look more natural to an untrained viewer.

          Looks like like every other raytracing demonstration I've seen: a bunch of reflective surfaces and mirrors that are impossibly clean and flat, with fairly poor textures. Most things in games aren't and don't need to be shiny, yet if you take the reflective surfaces out of this demo it would look awful. I'm not impressed.

    • Re:Beautiful (Score:5, Insightful)

      by ChronoReverse (858838) on Friday August 15, 2008 @11:20AM (#24615877)
      What on earth? How are those overly shiny objects beautiful in any way?

      The technology is probably better than that but the actual screenshots are distinctly ugly for this day and age.
      • Re:Beautiful (Score:5, Informative)

        by Anonymous Coward on Friday August 15, 2008 @11:53AM (#24616397)

        The screenshots look relatively ugly because of the hashed-together-demo quality of the environment textures. But it's not a texture demo, it's a raytraced lighting demo.

        Bare in mind this is ray tracing at a very rough and ready stage, but the potential is enormous. If you want to see the sort of effects it can achieve, check out some professional 3DSMax/VRay renders.

        There's a nice render here [wikimedia.org] for illustrative purposes.

        That's just a single frame with high quality textures, but it surely shows the potential.

        • by hr.wien (986516)

          It shows what can be done given (relatively speaking) unlimited time. Unfortunately that has no bearing on what is feasible in real time, as the Nvidia demo handily demonstrates.

        • Re: (Score:3, Interesting)

          by afidel (530433)
          No, for illustrative purposes of what ray tracing is capable of you have to look at something like this [oyonale.com], it's very very close to being indistinguishable from a photo. That took 21 hours on a P2-350 (465 MFlops) so on a GTX280 which is ~3,000 times faster it would take about 45 seconds to render, not exactly a playable framerate. We're a few doubling of transistor count away from being able to do photo-realistic ray-tracing at playable framerates.
      • Re:Beautiful (Score:4, Insightful)

        by phantomfive (622387) on Friday August 15, 2008 @12:08PM (#24616691) Journal
        Yeah, exactly...it's like Web2.0 of the graphics world....sure, the buttons are shiny, but that doesn't make them look any better. That is why people like John Carmack have suggested that full on ray tracing isn't the way to go.

        I absolutely do not understand the issue fully, but here is my take: in the early 90s, ray traced graphics looked way better than anything else. You could render a ball and people would say, "wow, that is so cool!" it took 30 minutes to render, but it could be done.

        Since then, 3D rasterization has come a long way. With texture mapping, commodity 3D graphics hardware, pixel shading, alpha blending, etc, we have games that look really, really good, without ray-tracing.

        Now ray-tracing is starting to become possible in real time, and I guess people are remembering how good it looked in the 90s and thinking it must still be the holy grail of graphics. In theory it's a good idea, render everything the way real light does.

        The ultimate question has to be: does it look better? Or is there another way we can use that processing power that will make the graphics look even better? My guess is that ray-tracing is a technique that will be useful in some ways, and will be mixed with techniques we already have now. Much like today we use 2D texture maps on 3D objects, and it looks good.
        • by nabsltd (1313397)

          Yeah, exactly...it's like Web2.0 of the graphics world....sure, the buttons are shiny, but that doesn't make them look any better.

          Basically, ray-tracing might be to games what Vista is to operating systems.

          It's prettier than the previous version, but the gameplay/OS functions aren't any better (and are sometimes far worse). There are so many games now that can quite comfortably be called "just another first-person shooter" that when something truly original comes out (e.g., Portal), it's huge.

          I can't recall anybody saying "well, Portal would have been good if the graphics had been more realistic."

    • Re: (Score:3, Insightful)

      They're nice work, but c'mon, how about some demo VIDEO instead? I'd love to see the full effect of the reflections in the Windows and chrome of the wheels, and the way the lighting moves...

    • by samkass (174571)

      One thing I noticed is that the curves and shiny surfaces look really, really smooth but that the straight lines look aliased and fake. The railings look like they were drawn in with a line tool.

    • by Phat_Tony (661117)

      Funny how things change, eh?

      I think Nvidia would have preferred a different previous naysayer for you to link to [slashdot.org].

      I heard the title of their talk at SIGGRAPH was:
      "Practical Real Time HD Raytracing With Nvidia Hardware: Suck It, John Carmack."

    • by Bombula (670389)

      Wow, those screen caps are gorgeous.

      Really? I was just going to say they looked pretty crap to me. I mean, they'd be OK in real-time on the X-Box or PS3 I guess, but certainly they aren't photorealistic and couldn't be used in film CGI. The car itself is fine, it's a nicely done model (Bugatti Veyron?), but it essentially has no textures - it's perfectly smooth. Maybe that's the point of this demo. But it doesn't look real by any stretch. Uncanny valley, big time.

      Worst of all is the lack of lighting

  • by Rogerborg (306625) on Friday August 15, 2008 @11:05AM (#24615613) Homepage
    Al Gore would like to have a word with you about just how important it is to beat photo-realistic hookers to death.
  • I had a tenant once, who stated that the first use of any new multimedia technology was always for, shall we say, *adult* services. In the sense they drove DVD sales (multi viewpoint, stop rewind), CGI, and so on.

    gah. the mind boggles what the animation crowd could do with this.

    On a similar note, when I did my BA years ago my dissertation was on the veracity of digital images, when there is no real referent to accompany the photograph, and the loss of credibility of images in the onslaught of photo re
    • by Moraelin (679338) on Friday August 15, 2008 @11:40AM (#24616173) Journal

      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: (Score:2, Informative)

        by Anonymous Coward

        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.

        Subsurface Scattering.
        http://en.wikipedia.org/wiki/Subsurface_scattering

        http://graphics.ucsd.edu/~henrik/images/imgs/layered_skin_model.jpg

  • by Ancient_Hacker (751168) on Friday August 15, 2008 @11:11AM (#24615723)

    The devil is in the details. Ray tracing with glossy surfaces is relatively easy. But if you want to simulate real-world textures like orange-peel, bark, hair, or skin, things can really slow down.

    • Bark isn't too hard to pull off at least form a technical standpoint, from an artistic standpoint it can of course be a bitch to pull off but that's a different matter. Hair is a bit trickier but you can usually get decent enough looking results. Orange peel has a bit of Sub Surface Scattering (SSS) but in most scenes you can again get away without it.

      So that leaves skin, for a long time realistic skin was almost the holy grail for CGI given that SSS and multiple layers are a huge component of skin but no

      • At least in the beginning I imagine skin features like you descibe would be pre-rendered into the texture as some sort of efficiency compromise. It's not like raster methods do a great job right now anyway. Most games are still going further into uncanny valley rather than climbing out of it.

    • by Ambiguous Coward (205751) on Friday August 15, 2008 @11:45AM (#24616281) Homepage

      Umm, no. I admit it's been a while, so my memory may be off, but I distinctly recall that procedural textures in ray-tracing are really, really easy, and add almost no (necessary) overhead to speak of. If you can find a way to do those things you mentioned with a procedural texture (those cases you provided are the textbook examples of how to do procedural textures, mind you) then you can almost certainly do them easily and cheaply. Any graphics course will have you rendering textured oranges inside the first week of the ray-tracing portion. Rainbowed CD undersides and the cool microscopic rings on the underside of a brass pot the day after that.

      I don't remember the implementation details, as it's been many years since I tried, but it's easy, and doesn't add any real overhead to speak of. Yes, when running procedural textures, you CAN make them heavy (it's a procedure: it'll do whatever the hell you want) but by no means is that a requirement.

      Which do you think is worse:

      • Loading a 10MB texture image that only works at certain resolutions, and eats up 10MB of space, or
      • Loading up a 1k code segment that generates the same (or similar) texture at any resolution, on the fly, and only generates the texture for the exact pixels you're looking at?

      Not to mention that if anything even close to the support given to the current texture models is given to procedural texture models, they will almost instantly outpace the current options and limitations.

      Did you ever notice that the early-generation ray-tracers supported procedural textures long before they supported the "regular" texturing model? There's a reason for that.

      -G

      P.S. Yes, I'm fully prepared for nit-picking you-used-the-wrong-word-here responses, so fire away. :P

      • Everything else I said above left aside, I think what I'm really driving at was this one statement:

        ...if anything even close to the support given to the current texture models is given to procedural texture models, they will almost instantly outpace the current options and limitations.

        -G

      • Which do you think is worse:
        Loading a 10MB texture image that only works at certain resolutions, and eats up 10MB of space, or
        Loading up a 1k code segment that generates the same (or similar) texture at any resolution, on the fly, and only generates the texture for the exact pixels you're looking at?

        If you're running more lines of code per pixel with a procedural than you are by simply looking up a memory location for an rgb value, how is that going to be 'no overhead'?

        Maybe I'm misunderstanding a fundamental concept of how raytracing works, so I won't be ashamed or argumentative if you can correct me on this, but I don't get how raytracing will make procedurals run nearly as fast when the renderer is going to have to ask a shitload of questions per-pixel about what that color is supposed to be. Do fo

        • by fractalus (322043)

          Well, for starters current 3D engines don't always do just a simple texture-mapping anyway; they can be doing environment-mapped reflections, bump maps, and so on in their fragment shaders. This is roughly the same level of complexity.

          On top of that, though, is the issue that when you ray-trace, you only generate textures for pixels that actually appear on the screen. When you rasterize, you don't always have your polygons ordered front-to-back so you end up rendering a pixel's texture only to have it repla

        • The way I see it, if resources were devoted to processing procedural textures instead of storing texture images, then that, at the very least, puts the two on an even playing field.

          What follows is train of thought, totally unorganized:

          Yes, RAM is cheap and thus you can store large amounts of textures in it for a relatively low-cost. But, in general, REALLY FAST RAM (like cache, or better) is NOT cheap, and so you DON'T store textures there. You store it in the cheap, "slow" RAM. On the other hand, if you ge

    • by caywen (942955)
      I'm admittedly only very journeyman in my understanding of RT (I've written some basic RT's). How would they slow down? You can process bump maps pretty easily - it's still just adjusting the diffuse light value based on a tweaked surface normal.
    • that's all fine and well, but it sure looks a lot sexier (proper curved surfaces) than rasterization which is what it's competing with

  • by rogerbo (74443) on Friday August 15, 2008 @11:15AM (#24615777)

    I just looked at those pictures and then checked a high res shot of Gran Turismo 3 Prologue on a PS3:

    http://o.aolcdn.com/gd-media/games/gran-turismo-5-prologue/playstation-3/22.jpg

    I don't see enough of an improvement to increase GAMEPLAY in any significant way. The reflection maps and shadows that are created by the current rasterization tricks are good enough that you suspend disbelief.

    I'd much rather the increase in GPU power be used through a GPGPU API for artificial intelligence, advanced physics simulations, fluid dynamics, flocking behavior or other things which could really add to gameplay.

    A few extra reflections and slightly softer shadows???? I won't even notice and neither will the average gamer.

    • by jamie (78724) * Works for Slashdot <jamie@slashdot.org> on Friday August 15, 2008 @11:29AM (#24615999) Journal
      I kind of assumed the big win was that game development gets easier. If your game is rendered by ray-tracing can't you spend more time on building the models, lighting and gameplay and less on fine-tuning rendering tricks?
      • by tgd (2822) on Friday August 15, 2008 @02:42PM (#24619315)

        The people writing the game, in most cases, are buying a library from a 3rd party.

        There's not much of a gain to be had from that.

        We used to joke about realtime ray tracing being two years away when I was in college.

        Fifteen years ago.

        The problem is, its always slower than rasterizing. You can get faster hardware, but as soon as you do people want bigger textures, higher resolution, more polygons and suddenly once again raytracing is too slow.

    • by Big_Breaker (190457) on Friday August 15, 2008 @11:41AM (#24616193)

      The gameplay improvement is in deformable physical environments. Combined with mainstream physics engines, raytracing would allow for a sea-change in gameplay by allowing interactive gaming environments.

      Raster methods rely on a bunch of tricks, many of which need to be precalculated for static maps. The most obvious example is binary space partioning tables. This leads to very static feeling environments that disallow interaction beyond doors of various types and moving platforms.

      • Uh, you do know that in order to do ray-tracing efficiently, you have to use data structures like bsps, kdtrees and octrees? I.e. Ones that you don't want to have to rebuild every frame because something moved. I get your point that you won't have to precompute lighting for radiosity, but even raytracing often using radiosity for global illumination.
        • I see your point and the point of fluffykitty. I guess my intuition is that the tricks are piled on so thick in your typical raster based FPS engine that in order to simulate lighting, reflections and transparency effects certain things, like the environment, need to remain static.

          Raytracing addresses some of these shortcomings of raster so that these tricks need not be used, a more ground up approach. That way the environment can be more dynamic as its features are recalculated in real time.

    • I'd much rather the increase in GPU power be used through a GPGPU API for artificial intelligence, advanced physics simulations, fluid dynamics, flocking behavior or other things which could really add to gameplay.

      I think you're missing the purpose of what a graphics processing unit is for.

      • by roystgnr (4015)

        I think you're missing the purpose of what a graphics processing unit is for.

        No, he's going beyond the purpose of what a graphics processing unit was originally for, and looking ahead to what General Purpose GPU computing [wikipedia.org] is going to [gpgpu.org] be for. [nvidia.com] There's nothing in the GPU that requires it to operate on polygons; the silicon is there to do parallel stream processing, and streams of geometry/texture/lighting/etc data are just one of the ways to use that.

      • by hardburn (141468)

        Both nVidea and ATI^H^H^H AMD are pushing GPUs for use for general computing tasks. The sheer number of transistors dedicated to processing means that even though they're tuned towards graphics, they can still be faster than a CPU for many tasks. Even when they're slower, they can be better on a price or energy usage point of view.

    • by Traa (158207)

      I'd much rather the increase in GPU power be used through a GPGPU API for artificial intelligence, advanced physics simulations, fluid dynamics, flocking behavior or other things which could really add to gameplay.

      You would have loved the AMD talk on advanced rendering techniques at Siggraph. Using DirectX 10.1 techniques they demonstrated a gaming scenario with 3000 characters (froblins, don't ask), each 1.2 million triangles at the highest level of detail, that demonstrated flocking behavior, AI, path fin

  • by MojoRilla (591502) on Friday August 15, 2008 @11:22AM (#24615903)
    Of course ray tracing, or one of its decendants, like photon mapping [wikipedia.org], will end up dominant. The question is when. Ray tracing is used now for rendering movies like Cars [computer.org], which are probably pretty much state of the art for computer graphics, and would be used for things like PC games except that is so computationally expensive.

    As to when rasterization will be replaced, the short answer is not any time soon. The article's title is misleading. It says "Intel: Rasterisation will be replaced in five years", while Intel's ray tracing guru Daniel Pohl actually says "Looking ahead five to ten years from now, I believe that rasterisation will be used less and less in games". Big difference there.

    So, I think this will progress quickly, but we won't be getting rid of rasterization any time soon.
    • I tend to agree. While ray tracing has a lot of potential, it is several years away from being usable on mainstream hardware, and in addition, during that time rasterization technology will further improve. So even if this demo will work on gaming PCs in 5 years, rasterization graphics may look amazingly better by that time.
      • Maybe the best course would be to selectively use ray tracing. Use rasterization for backgrounds and other low visibility or undynamic images and use ray tracing for the focus of the viewer's attention. That dragon you are fighting may benefit from ray tracing but the tree behind it in the far distance could just be rasterized.

    • by pr0nbot (313417)
      IThe thing I like about ray tracing is that it's more or less pure physics (as opposed to current GPU rendering is a clever box of tricks and hacks and approximations). So, you can implement a glorious renderer today, and just wait for the hardware to catch up.
  • by Ukab the Great (87152) on Friday August 15, 2008 @11:33AM (#24616045)

    I want NVIDIA to come out with a card that gives boring DOOM clones intriguing plots and compelling gameplay.

    • by kenp2002 (545495)

      I can fix it:

      East side cop finds his ex-wife dead and he's the primary suspect.

      Digging into the murder he finds his wife moonlighting with a weird cult operating out of the boiler room of a massive fast food corporation.

      They open a gate to hell, the cop gets possessed and proceeds to murder the entire city as a demon.

      Once the last soul is taken the gate seals up and the event becomes a cold case.

      30 years later: An ex-army gone PI chases down a filandering wife and her boyfriend to the ruins of an abandon me

  • I wonder (Score:3, Insightful)

    by ThePhilips (752041) on Friday August 15, 2008 @11:35AM (#24616077) Homepage Journal

    Meanwhile reader arcticstoat passes on Intel's latest claim that rasterisation will die out the next few years, possibly in favour of ray tracing.

    I'd love that to happen.

    But reality is that several best games I have played were ... 2D.

    Intel, Good luck adding RT to 2D graphics. ;)

    RT in my experience is rather expensive - on end of development. Not all games manage to exploit all lighting models. And RT needs that even more than actual 3D graphics. It would take some long time for games to adopt it. On side of CADs picture is much simpler: they are easy to fork $$$ for good and fast rendering.

    • The one thing I want (Score:3, Interesting)

      by Chemisor (97276)

      > 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.

  • by Tibor the Hun (143056) on Friday August 15, 2008 @11:39AM (#24616147)

    Like someone said a few months back, now all the games will be composed entirely of shiny balls, toruses, and checkerboards.

  • Slusallek's RPU was doing real-time raytracing with about the same hardware as Rage Pro, three years ago.

    They could afford to put a couple of souped up RPUs in the corner of a GPU without noticing the "lost" transistors and get this kind of real-time raytracing on entry-level GPUs *today*.

  • by caywen (942955) on Friday August 15, 2008 @11:52AM (#24616389)
    I think raytracing is going to be the only way to go in 5-10 years. As poly counts go up, average poly size is going to drop below 1 pixel, and the overhead of tracing rays will match the overhead of rasterizing tiny polys + scene overdraw, etc. Of course, what I fear is that all the games will start feature too much reflection on every surface, because they can.
  • I wonder how much control future ray tracing engines will give the programmer over scene search algorithms? If I'm doing a top-down terrain render, I'd want to have a super-simple O(C) first hit time (probably using a simple grid/bucket). If I were doing a space scene, maybe an oct tree. In either case, it sounds like a problem that can't easily be hardware accelerated.
  • I wonder if this is what Pete Shirley [blogspot.com] went to NVIDIA to do.

    The article and some of the comments here have oft-repeated myths about ray tracing. For example, ray tracing algorithms are generally simpler than rasterization algorithms, not more complex--though they do require more processing power.

    One commenter said this demo was limited to 3 rays per pixel. That may not be true. The article said each ray was limited to 3 bounces. That doesn't preclude firing multiple primary rays per pixel for antialiasin

  • Why a demo a Volkswagon?! That Volkswagon Veyron is not even good looking in real life... :(

  • And this systems costs how much? And consumes how much power? And needs how many P/S's to operate?

    They may have put on a desktop what it took a supercomputer to do before, but it's still a very expensive desktop, which makes it interesting, but hardly useful to 99% of us.
  • by Ihmhi (1206036) <i_have_mental_health_issues@yahoo.com> on Friday August 15, 2008 @01:29PM (#24617991)

    ...of the card [imageshack.us] that will be needed to run raytracing.

    I guess you micro form factor guys are kinda screwed.

  • by Funk_dat69 (215898) on Friday August 15, 2008 @02:51PM (#24619451)

    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!

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