Wolfenstein Gets Ray Traced

An anonymous reader writes "After showcasing Quake Wars: Ray Traced a few years ago, Intel is now showing their latest graphics research project using Wolfenstein game content. The new and cool special effects are actually displayed on a laptop using a cloud-based gaming approach with servers that have an Intel Knights Ferry card (many-core) inside. Their blog post has a video and screenshots."

Comments

I don't get it

[Yuioup]

Why build a ray tracer into a 4th game after doing it for Q3, Q4 and ET:QW. Why don't they focus on improving already existing raytracing code into the first 3 games.

I donnow but it seems like they're keeping themselves busy for the sake of looking busy.

Y

Re:I don't get it

[pieisgood]

Yeah, this project is simply here to validate itself.

I don't know if that's entirely true though. Carmack talks of slowly integrating raytracing technology into videogames. This research into raytracing in games could prove useful later in videogame development. As I understand most advancements in videogame visuals today are optimizations on old research. So I wouldn't rain on their parade entirely.

Re:I don't get it

[cupantae]

I can't understand why they're not giving people what they want: ray traced Nethack.

Re:I don't get it

[JCZwart]

This is Intel, not Id. It's a tech demo to show off what Intel's technology is capable of. Ray tracing scenes in real time was absolutely unthinkable just a few years back (and honestly I'm quite impressed with what they've achieved here, since ray tracing is about the most expensive (though also most realistic) way to render a scene in 3D).

Re:I don't get it

[AragornSonOfArathorn]

I can't understand why they're not giving people what they want: ray traced Nethack.

You can have ray traced nethack. Just print every screen on a laser printer with high-resolution TrueType fonts.

Graphics card are obsolete

[Orphis]

Mom, can I buy a new cloud to play Halo 10 ?

Re:Graphics card are obsolete

[Elektroschock]

Mein Leben!

Nothing to see here

[dsavi]

It's rendered in the cloud. If they managed to actually get more bang for the buck- i.e. made this run on conventional hardware- Then I'd be interested. They're just doing something that has been done before, albeit maybe not in real time (But you never know, seeing these new OpenCL apps), running it on high-end servers, and piping it into a small laptop. I'm not sure how much of an achievement this is, we've all heard of gaming in the cloud before.

Re:So many

[BodeNGE]

Oh my god, ... it's full of triangles!

Sign of the times...

[rh2600]

When a laptop packing a multi-GHz 64bit CPU with gigs of RAM gets called a thin client...

Poor ray tracing

[DarwinSurvivor]

Their ray tracer has a few issues.
-The player does not appear in the scope reflection (but his shadow does).
-The people's shadows are cast in a different direction than the car's.

Re:Poor ray tracing

[Purity Of Essence]

1. It's extremely common in FPS games for the player model to be excluded from the player perspective. It really complicates things and usually doesn't look good without a lot of extra work.

2. That's not the car's shadow. The building shadow is the shadow you are seeing. You can't see the car's shadow because the car is mostly (if not entirely) shadowed by the building behind it. The viewing angles were not suited for showing a shadow cast by any directly illuminated portion of the car.

Re:Poor ray tracing

[Anonymous Coward]

You are right, the player model is often excluded, but that isn't really necessary. Especially id Software is usually known to show the player model's shadows and refelctions (including mirrors) since Doom 3.
And if you really want a game with not only visible player model but actually pretty good player animation and physics, you should try out Dark Messiah of Might and Magic.

Re:Poor ray tracing

[ciderbrew]

This sounds like a John Lasseter I saw ages ago. Those guys are scientists not 3D artists. They can't see why it's wrong. It's job done when the maths work. I've not idea why they don't hire in a guy, most of these problems have been identified and fixed in the pre-rendered market years ago. Maybe extra lights kills the frame rate too much.

The worst example of 3D I've seen so far would be the "shadows on a mirror" trick - nice.

What's the point?

[pacinpm]

I know they just started but still... what is the point of this? There is no upsides to rendering. It's slower (you need 4 servers), it looks worse (they had no antialiasing, ugly smoke, no complex lightning). You can do some things like reflections and refractions and portlas bit easier than with other methods but most of the time you don't need 100% correct reflections/refractions (simplified models work quite nice) and security cameras where implemented in Duke Nukem 3D on i486 machines without problems.

Other than selling Intel chips I see no purpose for this project.

Re:What's the point?

[retroStick]

As someone who has dabbled with raytracing before, I would have to agree. It's an interesting tech demo of something that's possible, but not really of practical use. For instance, they showed the chandelier with a million polys - that's all well and good, but it's on the ceiling! If the game was actually being played, the player would never get close enough to see those clever refractions. (And even if they did, the demo shows the frame rate would drop to around 17-20 FPS).

Re:What's the point?

[leuk_he]

There is no point now. But in 10 years (maybe faster) the cpu speeds has increased to the point that you don't need a high performance cluster. It would be nice if you can at that moment run a game without an advanced GPU. in full detail.

If you have to start research about raytracing when the hardware is cheap enough you are too late.

And as for quality: fun of a game has little to do with grpahics quality. But it has to advance, or else we still would be looking at pong like graphics. people buy 1080p tv at sizes where it almost impossilbel to see the difference with 720p. But they still want the best quality.

PS, when they speak of wolfenstein i still think of the 1991 prequal to doom that was playable on a 286.

Re:What's the point?

[TheRaven64]

Not quite. The complexity of rasterisation is (very) roughly O(number of polygons * number of lights). The complexity of ray tracing is O(number of rays). The number of primary rays is the number of pixels (sometimes multiplied by 4 or 9). The number of secondary rays depends on the number of lights (you fire a ray into the scene and then a secondary ray from what it hits to each light). This means that increasing the complexity of the scene does not affect the ray tracing time very much, but increasing the resolution does. On the plus side, ray tracing gives you shadows and reflections for free. It also degrades more gracefully - you can get a lower quality scene quickly (just from one primary ray per pixel) and then add the details from secondary rays and extra rays if the user doesn't move. In contrast, rasterisation tends to just lower the frame rate.

Re:What's the point?

[slashdotjunker]

1. Immediate lighting rasterizer = O(S*N*L)
2. Deferred lighting rasterizter =O(S*N)+O(S*L)
3. Ray tracer = O(S*log N*L*D)

where N is the number of solid 3D elements, L is the number of direct illumination lights, D is the indirect lighting depth and S is the number of screen elements.

No matter how I look at this, ray tracing is not very compelling.

Once upon a time, we thought ray tracers were fast. If we hold screen size as a constant and set the number of bounces to 1 for a fair comparison to a 1992 era rasterizer we get the "classic" complexity analysis comparison.

1. Rasterizer = O(N*L)
2. Ray tracer = O(log N*L)

Winner: ray tracer. However, a few things have changed since 1992. First, screen size is important and should not be ignored. This is due to the increasing importance of screen space effects. Second, deferred lighting broke rasterization in half. Third, rasterizers can now do convincing shadows and fake global illumination. So, to keep up with the quality of the average 2010 rasterizer we have to set D>1. This is a 1-2-3 knockout combo for ray tracers.

Rasterizers are the current complexity king. Now, I'll tell you why it will remain the king. Ray tracers have an architecturally bad design. It looks like this:

for p in rays:
    for i in items: raytest
    for s in lights:
        for t in bounces: ...

There is a beautiful elegance to this. It is a good way to learn how to do computer graphics. Unfortunately, this kind of architecture always leads to bad complexity that looks like this: O(f1*f2*f3*f4 ...).

Rasterizers have a better basic architecture. Scatter-gather type architecture tends to lead to nice complexity like this: O(f1)+O(f2)+O(f3)+O(f4). Don't take my word for it, look at the history. The O(N*L) immediate rasterizer got broken up into the O(N)+O(L) deferred rasterizer as soon as enough memory became available. Indirect lighting followed the same pattern.

I'm not saying that ray tracers will always be slow. But, I _am_ saying that if ray tracers ever become fast again, it will be because they have been architecturally restructured into something that looks a lot like a rasterizer. In such a case, any claimed victory by the ray tracer would be a pyrrhic one.

Project Offset

[nacturation]

Anybody know what happened to http://www.projectoffset.com/ ? They released tons of killer videos showing an amazing game concept, outstanding real-time effects... then Intel buys them and... nothing!

Re:Project Offset

[Pharmboy]

but about every experienced game developer in the field (including me) realized that super-ambitious projects started by a handful of indies in a basement rarely makes it to the shelves nowadays.

There are some exceptions. Valve has a history of buying up these groups and hiring the original people. Day of Defeat, Portal, Team Fortress all started that way, and they have done the same with other small groups as well. One more reason I'm a fan of Valve, they buy talent and put them to work, giving them the opportunity to expand their original dreams.

Does it run on a Beowulfenstein Cluster?

[Hadlock]

Yeah, you're rendering Wolfensetein on a cluster.... but can you get Wolfenstein running on a Beowulf cluster... or, dare I say it... a Beowulfenstein cluster???
 
;)

Ironic

[Anonymous Coward]

That none of intels graphics processors have any hope in hell of real time ray tracing.

fps counter lying?

[citizenr]

Chandelier part displays 40 fps on top right, but you can clearly see on the screen that its more like 15. Not to mention unimpressive difference between RT and normal renderer. I was expecting something more real life.

Cloud gaming and latency

[loufoque]

The very idea of using the cloud to render a FPS is preposterous and will never work in practice, for obvious latency reasons.

Re:Cloud gaming and latency

[Purity Of Essence]

Is that supposed to be ironic given the runaway success of the OnLive game service? http://www.onlive.com/

Re:Cloud gaming and latency

[Thanshin]

The very idea of using the cloud to render a FPS is preposterous and will never work in practice, for obvious latency reasons.

How else will you start training for the moment when that computing capacity is on every PC?

You use the cloud, ignore the lag and build an engine ready for the generation of computers that will come in five or ten years. You'll lose a lot of your investigation, but anyone who starts studying RT at that point will be years behind you.

Re:Cloud gaming and latency

[Fross]

Do you have anything to back up that "runaway success" claim? As far as I can tell it's been shunned by hardcore gamers due >100ms input lag, and I've not seen anything about it having huge takeup.

Re:Cloud gaming and latency

[tibit]

I don't know if latency is any sort of a problem. You're talking of a LAN connection. This technology is not meant to render stuff somewhere out there on the intertubes. It needs to be in the same building, or on the same campus.

That's... Lovely.

[L4t3r4lu5]

10fps to be able to see glass refraction on a surface so small it's totally inconsequential.

Yawn. Wake me up when they get refraction working with a playable framerate like Source had seven years ago. Regarde

Re:The surveillance station. ...

[WhitetailKitten]

You wanna know the last game I played that featured this "surveillance camera" business?

Duke Nukem 3D


Ohhhh, snap!
/* OK, it was one monitor at a time, but that's arguably a tactical decision to not let the player see every camera at once */

Re:And yet the players still don't move like peopl

[daid303]

Nah, the respawn time sucks in Afghanistan.

Joke? Puhleeze.

[RulerOf]

My 486 ray-traced perfectly. I don't understand why we're using processing power to show glass reflections in ray-traced sniper scopes when all the old monitors showed the reflections of people approaching from behind already!

Stupid matte LCD panels.

You were supposed to woosh him ;)

Ahh Youth

[kenp2002]

"The surveillance station. At a wall in the game you see twelve screens that each show a different location of the level. This can be used by the player to get a tactical gaming advantage. Have you ever seen something similiar in a current game? Again - probably not"

Yes, In Duke Nukem 3D... over 15 years ago. And again in a bout 40 other FPS games that followed including the Unreal series, more then a few Quake maps especially in capture and control maps.

"There is nothing more amusing to watch then some young kid discover something old and think it is new" - That quote in action.

Re:Ahh Youth

[Sigma 7]

Duke Nukem 3D, while it did have surveillance, only had one screen. If you stopped watching the screen, it would render a blocky image for one of the cameras it monitors rather than a clear image.

It took until at least the Unreal Engine before a multi-screen display was possible, and I'm not sure how much that impacted the framerate.

Re:Ahh Youth

[SheeEttin]

Red Faction had security cameras in 2001. Multiple screens on-screen, but I don't remember if you could change them. Half-Life 2 (or one of the episodes) had security cameras, too, that you could change, but I don't think there were more than one at a time. (I don't think it's an engine limitation.)

Re:Moore's Law is NOT a tool

[ksandom]

Moore's Law has become an expectation, and thus a design method from a marketing point of view. This is particularly visible in harddisks where they release a harddisk that has been designed to scale up, but only contains a single platter, then a little over a year and a half later, the same hard disk is released with a second platter. The expectation allows them to get ahead, while the previous iteration is slowly allowed to get to it's full potential. Then they work on the next thing and while the current platform grows.

Re:So many

[Rockoon]

This is the true advantages of raytracing. A rasterizer would have to deal with each and every triangle in that chandelier.

Rasterizers scale on O(triangles) while raytracers scale on O(pixels * log triangles). I dont remember if it was Microsoft Research or something out of Intel, but 5 or so years ago they did some scalability testing and concluded that about 1 million polygons was the sweet-spot where raytracing and rasterization were about equal in efficiency using the per iteration constants derived in their testing.

This was based on visible geometry only, so no pretending that the fact that rasterizers can use logarithmic data structures for hidden surface removal, that that makes any bit of difference.

Since then, triangle counts have remained about the same in games (with more per-pixel processing being done to simulate more geometry,) but the number of pixels have quadrupled as higher and higher resolution displays have become common. Yet they are reaching the limits with the fakes that can be done with shaders, and resolution is probably not going to go through another quadrupling, so raytracing really is comming.. just not quite yet.

When the polygon counts do get high enough, there will be no looking back. Raytracing will be here to stay after that because of the way it scales. At 1 million polygons, a raytracer spends 20 iterations per ray cast using a logarithmic structure.. doubling the number of polygons to 2 million only adds 1 more iteration.. or about 5% more processing power required, and doubling again only adds another ~4.5%, and so on.. meanwhile each doubling of polygons on the rasterizer literally doubles the processing power required.

Re:Hmmm

[tibit]

Just thinking about the bandwidths is interesting. Start with 150E6 rays per second. Assume that to traverse the binary space subdivision data structures takes, say, 256 bytes, along with another 256 bytes worth of data for the polygon. That requires ~77 gigabytes/s memory bandwidth, sustained. So in practice you need the bandwidth of 6 fastest DDR3 sticks. And your algorithms better kept the CPUs pipelines full, and did proper prefetching, or else cache misses will have you for a day's worth of meals.