Parallel worlds

You would still need to create light sources and define what wavelength and amplitude of light they produce. Instead of having a graphic texture attached to them surfaces would have to be defined by what wavelengths they reflect in certain areas (although the net result is a fairly similar effect as most surface profiles would resemble textures, and bump-mapping to scatter the light rays effectively would probably feature as well.

Volumes would be given an index of refraction so that air and water interfaces would work realistically, although getting water to ripple correctly would still present some challenges - fluid dynamics is a nasty thing to simulate. Dust in the air would create additional work for the processor

The way I'm thinking about it, games would be made in a similar way - the only difference is in how the graphics engine renders things. If anything it may become slightly easier, as instead of HDR and all that having to be created by additional effects it would occur as a natural feature of the raytracing process.

The more I think about it the more issues it throws up, but they can all be solved with sufficient computational muscle - the emergence of which is, after all, what kicked this whole debate off

Disclaimer: All of the above is total guesswork by someone who may well not have a clue what they are on about

 

If raytracing kicks off in a big way am I right in thinking Nvidia will no longer have a market for it's graphics cards as the CPU will do all the calculations?

 

Not really, dedicated raytracing hardware already exists, but is restricted to the professional market, and as such are crushingly expensive for even the most enthusiastic home user.

Anyway, there is going to be a huge legacy market considering how long fans keep playing their favourite games. Though it could get interesting, should the changeover happen in some Twilight Zone-esk overnight conspiracy of silence fashion. "Open-GL and Direct 3D compatible cards? I'm not certain what your talking about sir, but might I be able to interest you in this new Nvidia RayForce 6000"

I'd imagine the changeover will be a gradual thing, with extra effects being added as they can be done easly, little bits of raytracing code that can work on the current graphics hardware, or on the CPU using software renderers. I'd also imagine that support for the old raster standards will be continued for quite some time. Of course it may be that adding in a raytracing board may be the next path for dual card graphics, a current style card and a new style raytracing card.

Personally I'm rather salivating at the thought of dedicated raytracing hardware coming down to the consumer level, being able to use in a dedicated coprocessor in rendering jobs alongside the CPUs sounds like a great way to reduce rendering times. Or it could be tied into the realtime preview for modeling packages, to be able to what the model would really look like, rather than the half textured approximations that are all current modelling packages can manage.

 

For anyone that doesn't understand the potential of this, perhaps a picture would be helpfull?



(Full size @ http://upload.wikimedia.org/wikipedia/commons/e/ec/Glasses_800_edit.png)

Personally, the thought of things looking that realistic, make me amazed. The idea that quad cores could start stuff like that going makes me rather excited.

 

To the guy who asked about the Cell here is a video

here is the video
i dont think 2007 but 2008 sound like when we start moving towards it and 2009 will be big year for raytracing

 

I may be totally off the mark here, but aren't graphics cards just processor cores that are optimised for graphics processing? I.e. theoretically could a powerful enough processor emulate a graphics card?

If this was possible, maybe through software emulation (yes, I know you're all wincing at the idea of software acceleration but a game from five years ago could probably be emulated on a core 2 duo), then raytracing cards may also be able to adapt to standard graphics processing at a significant loss of efficiency/power

 

Hold on a second. Who said we'd demand HD resolution at 60 frames a second of the first ray tracing games/hardware?

Most people watch movies (for example, Pixar movies) at 640x480 with 30 frames a second on crappy tv's. How good does that look?

So let's try a different calculation. 800x600 pixels x 15 raysegs x 60 frames = 4.32 million raysegs.

I don't know about anyone else, but I'd be happy to play a ray traced game at 800x600.

However, I find it hard to believe that pictures like the one linked too above would be possible. There are probably other limitations (art budgets being a major one).

 

What you mean is hardcore gamers with big budgets/deep pockets. I'm happy if my computer can PLAY the game at 1024x768 with nominal graphics.

If the hud-bub regarding the PS3 price is any indication then gamers are CHEAP AND DEMANDING. So unless 20"+ widescreen moniters, good ones, suddenly become dirt cheap along with raytracing and graphics cards then I think people will settle for 800x600 or 1024x768 raytraced games at 30fps.

 

In, say, Doom IV? None, zero effect. 95% of the time your cores will sit entirely idle, with a black screen, until you hear something, you twitch your mouse, and then use two or three cores for three seconds thanks only to the glare of your gunfire; three seconds of a gloriously photorealistic slide-show. Then back to total blackness. Which is good, with no glare from the monitor, no one will see that you wet yourself in the dark room.

Jokes aside, that picture up there looks awesome. Something to aspire to in a few years!

 

On a completely different note I'd just like to say that with photorealism like the picture above I think CSI type games could start to take off.

Can you imagine investigating a crime scene that LOOKED real but was really a simulation? It would be AWESOME! Then again I'm a CSI geek so that could just be me.

 

Let's be clear though, raytracing as described in the original Intel article will not come close to rendering this scene at all realistically. There are several effects at play here that can't be captured by bouncing a finite number of rays.

The most obvious is the window reflection which is an area light source. Raytracing as described in the article is only effective with point light sources. Sure you can optimize for square light sources by sending a ray to each corner and then doing some interpolation, but that's already increasing the number of rays by a factor of 4, and that's only a basic quadrilateral light source. And its only the tip of the iceberg for this scene.

The concentrated spots of light (caustics) will not show up with traditional ray tracing techniques. Diffuse reflection (hold a colored, but non-reflective object near a white wall). Depth of field (again requiring more rays). Also, true volumetric rendering can't just bounce rays off surfaces, it has to take into account translucent materials. For an example, consider the renderings of two glasses of milk at http://www.cs.sfu.ca/~psabzmey/personal/graphics/report.html.

Those were created with the wonderful PBRT software (free for educational use). Check out the gallery. All of those images took hours and hours to render on modern machines.

The key to photorealism is something called the global illumination equation which is actually an integral of an entire scene that represents all light interaction. The problem is that the integral is impossible to solve for any non-trivial scene and can only be approximated. Using Monte Carlo rendering techniques such as photon mapping one can render photo-realistic scenes (they will appear noisy if not given enough time to map sufficient photons).

I'm not familiar with modern gaming graphics algorithms, but I guarantee you that they are all based on shortcuts and approximations to take the computation time out of raytracing. There won't be a single moment where we switch to raytracing and then suddenly we have photorealism. The reason real time graphics look as good as they do is because of a lot of brilliant optimizations that have made the approximations much faster with minimal loss of realism. Where exactly you draw the line between 'raster' graphics and raytracing is unimporant. The fact is that we will continue to see incremental improvements in both rendering techniques and hardware, but a 4x or 10x or 100x speed improvement is pretty much a drop in the bucket when it comes to bringing state-of-the-art rendering algorithms to real-time processes.

 

I've spoken to people that have done raytracing for their degrees. And it literally takes days todo it properly on fairly modern equipment.

http://www.pjblewis.com/home/

 

http://www.realstorm.com/realstorm/downloads06.html

 

With regards to the above picture I linked, I didn't intend to imply that we could move suddenly to graphics that good with raytracing, just that in a few years we could be there. I'm aware things like that currently take hours to render, but with raytracing that is where we could get to in a few years, assuming the steady increase in comptech we've had since the transistor was created(pretty much).

I can't wait for raytracing to begin along the path towards things like this.

 

nor can I, it seems as though this will be the future for applications using this etc, but also processors will need to be changed to since the technology of silicon based processors has been stretched to its limits (heat etc) and they cannot continue to keep shrinking it

 

I don't see why one couldn't just decrease image quality of RT when something gives it a performance hit. Say we give settings of 1024x768 at 30fps, giving the engine 1/30th of a second time to come up with each frame. From what I've seen when rendering with RT the image quality gradually improves like when a progressive JPEG loads, but instead of starting at the top and working its way down the engine could use an algorithm to scatter its efforts around the center of attention: the center of the screen.

This would mean the edges remain blurry when there is a performance hit, but the center of the screen is reasonably sharp; and no slide-show.

If this cheating-mechanism could be made to look like the noise seen in high ISO film photographs, it could actually be a rather cool effect.


I'm sure there are a lot of other shortcuts that could be used aswell. After all, you only need to fool the eye; not render photorealistically.

 

Welcome to the boards, nosforit! Interesting idea for a first post, have a cookie

 

Why thank you.

I just wish I had the know-how to modify the OpenRT engine to demo this idea. Though it probably would basically involve telling the engine to instead of starting from 0 and going +1 from there to work with a 3D bell-curve centered on the screen, the comparative step up in complexity is quite high.

Plus there is the issue of teaching the engine to start with the next frame after 1/30th of a second too...

Maybe I should talk with the OpenRT devs instead of blabbering here? Eh? Hehe. =)

ED:
Nevermind OpenRT. Apparently it isn't Open Source after all..

 

I think the article wasn't really focusing on the concept of a quad-core system processor doing the raytracing in realtime...if you read the linked article, you'll see that Intel is working on developing "RPUs", which will supposedly work in tandem with the GPU solely to perform ray-tracing duties. That would leave the processor available to render AI and the other stuff it's usually held accountable for...minus physics, assuming the PhysX engine is going to catch hold sometime soon.

Great article...I hadn't hear much about ray tracing in years, it's nice to see it brought back to the forefront, at least for enthusiasts.

 

For an ordinary game, you'd be somewhat right, but a raytraced game would be a completely different paradigm. People would have different expectations.