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Carmack Speaks On Ray Tracing, Future id Engines
Vigile writes "As a matter of principle, when legendary game programmer John Carmack speaks, the entire industry listens. In a recent interview he comments on a multitude of topics starting with information about Intel, their ray tracing research and upcoming Larrabee GPU. Carmack seems to think that Intel's direction using traditional ray tracing methods is not going to work and instead theorizes that using ray casting to traverse a new data structure he is developing is the best course of action. The 'sparse voxel octree' that Carmack discusses would allow for 'unique geometry down to the equivalent of the texel across everything.' He goes on to discuss other topics like the hardware necessary to efficiently process his new data structure, translation to consoles, multi-GPU PC gaming and even the world of hardware physics."
It as if hundreds of ray tracing fanboys cried out at once, and were silenced.
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Don't feel bad, he has probably never heard of you either.
Hi, I Boris. Hear fix bear, yes?
A developer who coded the engines that nearly all PC first person shooters have run on. That's obviously not enough to accept his words without hesitation, but obviously the person knows more about high-performance 3D rendering than a random coder like myself.
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My biggest concern with where he is going with this is that it does not sound like it will play very nice with physics. In page two he makes some comments on how characters and other animated elements will still likely be done with more traditional methods and then mixed with this for the static objects like the world.
The problem with this is that we are moving more and more towards interactive environments where everything from the ground to the flowerpots are breakable, bendable or movable. It doesn't sound like this new system will play very nice with physics intensive or highly interactive environments. Now, i could be completely wrong. He doesn't address the point directly. But it is still a point for concern.
Because he is more of an engine/renderer designer than game developer.
Its his job, and im pretty sure his passion to think about stuff like this.
You mad
Why not analyse his argument and judge it on it's merits rather then throw it out simply because he is working on an idea of his own?
Plusses:
- One of the primary fathers of the FPS genre.
- Wolfenstien 3D
- Doom
- Quake 1
- Quake 2
- Quake 3
- Endless articles and commentary on the field
- A shitload of stuff I'm forgetting
Minusses:- "Thought multiplicative lighting was the way to go, rather than dealing with the performance hit of additive lighting in Quake 3."
Conclusion: Carmack sucks!I mean, seriously, what's your point? The man's not actually a God so we shouldn't listen to him? Is there somebody more experienced I should prefer to listen to? Is "n3tcat" the handle for somebody with thirty years experience in first-person shooter engines or something?
John Carmack == Commander Keen == id Software == Doom = Wolfenstein == Quake == ??
You've never heard of any of those? the guys you mention might not even be in gaming if it weren't for Carmack and John Romero.
Every time I start to have faith in humanity, I ruin it by driving to work between 7 and 8 am.
In other news, all games will now consist of reflective spheres moving around on checkerboards...
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Commenting on the fact that it is unsurprising that someone working on a different technique favors that technique over raytracing is not throwing anything out.
Its not a comment either way on the merits.
Were I to comment on the merits, I would point out that his position is both fairly obviously correct (in that sparse voxel octrees or something quite like them is almost beyond question the key to raytracing that's useful for reasonable quality in realtime), and entirely incorrect in his characterization of what everyone else is pushing: he pretends that "everyone" is pushing the most naive, brute force approach to raytracing, in which you don't use any kind of bounding volume structure and just do intersection tests against triangles. I've seen literally no recommendations that do that: almost all involve some form of bounding volume heirarchy, and sparse voxel octrees are just one instance of that (perhaps a fairly ideal one, and that's great). (Also, raytracing isn't limited to triangles, although most performance comparisons of raytracing to raster-based rendering methods use models constructed from triangles because it allows you to compare same-model performance of the different mechanisms; raytracing engines, however, don't generally need to decomposed curved objects into triangle-based approximations to render them in the first place, although this can sometimes be more efficient.)
TFS further misleads by suggesting that Carmack is proposing an alternative to raytracing, when really what he is proposing is a particular approach to raytracing, and, particularly, a particular approach in one well-known problem area in raytracing to which there are currently a whole array of approaches. And his focus on what he wants to get out of raytracing is a little different. But, essentially, his piece, while there are some potentially good criticisms on some particular aspects of and arguments for Intel's specific approach to raytrace, is in accord with (not opposed to) the general idea that raytracing techniques are going to be increasingly important in gaming.
Is that enough "on the merits" for you?
Yet, when I play a game, I'll admit, I'm not playing glaring attention to these faults. The last thing that really bothered me in games was 16-bit color banding and I haven't seen any of that in, oh, like 3 or 4 years.
The gamer side of me agrees with Carmack on things looking cool who cares if it's wrong, the geek side of me is angry and demands it be pixel-accurate.
More Twoson than Cupertino
Funny. It's just freaking amazing that someone would even stoop so low as to mention Gabe Newell and not know Carmack. Hell, the original Half-Life is written on the Quake engine written by Carmack.
Every time I start to have faith in humanity, I ruin it by driving to work between 7 and 8 am.
Meanwhile the rest of us have been enjoying these articles immensely because we get to obtain some insight about what each of the major players are thinking in regards to Real-Time Raytracing. The great thing about obtaining insight from others is that you can then use your newfound insight to come to your own conclusions.
If you're simply looking for a consensus from the industry, don't expect one for a long while. The concept won't entirely be accepted until someone goes out there and proves it out. Just like high-quality 3D graphics were thought to be too slow on the PC. Until game creators proved out a few different methods to make them usable, that is. (Starting with Wing Commander, moving to Wolf-3D, Doom, Duke 3D, and eventually Quake. After that, the industry said, "Welp, we better make some hardware for this." And thus 3DFX was born.
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I doubt any mod team was hit harder by that fact than mine. Yet, I can't fault him for the decision. It's unlikely anyone on my team did/does. By supporting almost every hardware graphics accelerator on the market at the time, Quake 3 almost single-handedly fostered the feedback loop that drove mainstream adoption of dedicated graphics accelerators.
You sound like someone that's had the same thought every serious modder/engine-licensee has ever had; "if they could have just included/modified this ONE feature, my game would be feasible/better."
Yet you haven't encountered that phrase enough times to appreciate the fact that engine developers have to draw a performance line somewhere. Your desired feature just happened to be on the wrong side of that line.
Further, engine-developers of John Carmack's caliber would (I promise you this) love to have supported every feature you've ever thought of (and more). John Carmack's always been on the cutting edge, usually refining it. He sometimes makes decisions that are a matter of taste that you can feel free to disagree with him on, but that particular feature wasn't one of them.
Now if John Carmack is as legendary as /. is making him out to be, why isn't it John Carmack's Quake/Doom?
George Washington is pretty legendary, but we don't have a George Washington's America, do we? The name is irrelevant. How could the guy who basically invented the First Person Shooter not be legendary? When it first came out, the original Wolfenstein was the most highly optimized game I'd ever played. I still remember thinking it wouldn't run on my slow-ass computer, and being blown away when it ran fast as can be.
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Give me a little credit here. I am not suggesting that everyone blindly intersects rays with a huge list of triangles. That would be absurd, and I assumed everyone understood that. What you might have missed is that I'm not proposing a sparse voxel octree as some form of bounding hierarchy to reduce intersection tests against triangles, I am proposing that it REPLACE hierarchies of triangles or other primitives for some data sets, and this brings about significant improvements (data size) that you wouldn't have with even infinitely fast conventional ray tracing. I'm also not trying to say that this is some novel brainstorm of mine, but I have some practical experience with the direction, and I think it has promise.
One of my major points is that this is all still theoretical. I don't know what is going to be the right architecture for next gen systems. Neither do you, or Intel, Nvidia, Microsoft, Sony, or Nintendo. If I had to place a bet, it is that rasterization will still be dominant, but it is a Good Thing to have lots of people doing research into various alternatives. All the players have their own agendas, but we will all know the big win when we see it.
John Carmack
RTFA, you didn't understand what the guy who wrote the article was saying.
Dude, you got pwned by JOHN CARMACK!
"I mean, seriously, what's your point? The man's not actually a God so we shouldn't listen to him? Is there somebody more experienced I should prefer to listen to? Is "n3tcat" the handle for somebody with thirty years experience in first-person shooter engines or something?"
Many people with years of experience still make god awful mistakes. Experience can only take you so far considering that experience is also the reason why companies stagnate because people get locked into a certain way of looking at things.
In our current generation codebase we have moved to completely separate representations for rendering and physics, and I expect that to continue in the future. The requirements are different enough to merit different internal storage.
John Carmack
Tracing into an SVO structure can be done with almost a Bresenham algorithm, and when you reach whatever depth of descent you want (a critical factor, you aren't going all the way to final detail on every trace), you pop out whatever data is stored there (probably some vector quantized BRDF sort of thingy) and run a "fragment program" on it.
The data sets for a game world represented like this would be massive, but it is intrinsically well suited for streaming, even over the internet, which may well be the dominant media distribution channel in the timeframe we are looking at.
John Carmack