Ray Tracing in the future?

yes. it will.

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If that''s not the help you''re after then you''re going to have to explain the problem better than what you have. - joanusdmentia

davepermen.net

Speaking as one who is very qualified to comment on such matters, yes, raytracing will be the graphics rendering method of the future - specifically, realtime photon mapping.

There have been a lot of discussions about this topic here on GDnet; some of the better ones can be found here and here. There''s also a bit on radiosity here, which includes a sometimes less-than-civil debate on how raytracing is better than radiosity.

Enjoy

Take a look at the Realstorm Raytracer. It''s a realtime-raytracer demo. Just take a look at the site, and try out their demo.

My machine (XP2800+,1GB-DDR333) gets an average of 2.8 fps at a resolution of 640x360. Not quite usable for games or other applications just yet. Even more so, if you take into account that most games also need things like physics and ai, which require their share of cpu power.

Then take a look at one of nvidia''s current demos like Last Chance Gas. If you don''t own a GF-FX take a look at the video they provide.

My idea is that cards like the Radeon or GeForce will slowly adobt more and more features only found in raytracers a few years before, increasing the visual realism to a level where you can''t distinguish between raytracing and realtime rendering.

Also, why should you let all the processing power included in such cards go to waste and return to cpu-only dependand raytracers? I don''t think processor speed will take such a leap that it can do the same demo in 1024x768 @ >100 fps in the near future. And even if, GPUs will have developed too, providing visual results close to that of a raytracer and freeing up cpu cycles that can go towards more realistic physics for example.

Don''t get too excited just yet, though. I''m pretty sure the hybrid approach will remain far more usable than plain raytracing for quite a while.

- JQ

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Original post by Wildfire
Also, why should you let all the processing power included in such cards go to waste and return to cpu-only dependand raytracers? I don't think processor speed will take such a leap that it can do the same demo in 1024x768 @ >100 fps in the near future.

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*hint* Hardware raytracing */hint*

SaarCOR

I dunno how long it will take, but I'm pretty sure HW raytracers will surpass rasterisers at some point


[edited by - Eternal on November 17, 2003 4:43:18 AM]

[edited by - Eternal on November 17, 2003 4:44:12 AM]

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Original post by Eternal
*hint* Hardware raytracing */hint*

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That's what I was actually trying to get at with the paragraph above that

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My idea is that cards like the Radeon or GeForce will slowly adobt more and more features only found in raytracers a few years before, increasing the visual realism to a level where you can't distinguish between raytracing and realtime rendering.

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Of course, I'll take a while before you see that Or maybe not I just doubt that we'll go back to single cpu solutions as opposed to cpu/gpu solutions very soon. I think neither Ati nor nVidia want to go out of bussiness and thus will keep improving their cards, in whatever direction will give better visual results then any software raytracer can do in realtime at the same framerate and resolution.

//edit: My messing is spelled up. Me tired. %|

// edit2: I forgot to mention: The above benchmark results are with radiosity and depth of field disabled. I never had the patience to run the demo with that because it slows down things at least by a factor of 10.

[edited by - Wildfire on November 17, 2003 5:09:45 AM]

Id say about 5 years after the likes of Pixar and PDI stop using rasterization as their primary method of rendering seems a reasonable guess (so 5-10 sounds about right).

Wether it will be done on CPUs or GPUs depends on where the market for PCs is going. CPUs designed primarily to run legacy code are lame ducks compared to more parallel designs such as GPUs (even with huge process and R&D advantages). If the mainstream CPUs start being designed primarily for parallel processing and for legacy processing second then maybe the GPU tasks can be reintegrated with the CPU.

Sony is moving their console in that direction with Cell, but PCs are not at the moment.

I won''t be surprised if raytracing becomes the way of realtime graphics in the future.

I remember Yu Suzuki wanting to use raytracing to fully experience Shenmue on the Dreamcast. But as he said, at that time, this was not possible. But i doubt it will replace rasterization in the next 5-10 years.

WildFire: you should get much bether results actually, i think.

WildFire: the nvidia demo is just a plain hack. there is nothing real usable about it. i hope you know that. (guess why the file is that big..)

PinkyAndThaBrain: rasterization stopped to be the single way to render for Pixar and friends yet quite a while ago. Ice Age was the first full-raytraced movie.

WildFire/Pinky and all others: RealStorm performs very bad on pentiums, as its really not written for it. so we can''t see if hyperthreading could help. but if you read about the future of cpu''s, you know that amd''s next plans, k9, are planned to be in 2-3 years. the main difference to now will ONLY be that those k9 are just like k8 (athlon64, opteron), but several of them in one chip. up to 32 they plan. similar to hyperthreading, but more split => more behaving like real 32 parallel cpu''s.

intel plans the same. hyperthreading gets extended to "real dual cpu in a chip". and it gets extended to 4, 8, ... cpu''s in a chip. this is all plans of the next some years..

and realstorm normally performs much bether than what WildFire reports actually. you sound more like a 2000+ system. i''m still waiting for the first 3200+ a64 results.


with those next gen cpu''s, wich are planned over the next years, i think yes, in 5 years, raytracing is very simple doable on cpu''s.





oh. and i''m very against supporting todays hw to evolve more. reasoning is simple: they split more and more completely away from being part of your system. think about it. they have their own memory, their own chips, their own datamanagement. and they have a very fast lan-like connection to the system (or merely adsl), called agp. this system is VERY inefficient. just think how powerful your gpu could be if you could plug it into the second slot of a dual opteron mainboard. direct memory access to the system, direct talking with the cpu, etc. full memory bandwith all the time. no need to TRANSFER memory at all.

it would perform much bether.

thats why i''m more for a multiprocessor system, and the gpu just as another processor, optimized for stream-tasks.

there are cases where IGP beats even todays leader gpu''s. and that is, when they have to share and co-work with the cpu.

the hw gpu design limits. not only because it rasterices. but, too, because it does. of course.

raytracing is way to go. and it will not happen on gpu''s. just because they are too proprietary anyways.


thats my guess.

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If that''s not the help you''re after then you''re going to have to explain the problem better than what you have. - joanusdmentia

davepermen.net

I guess this post proofs the fact that near future is over-estimated, whereas far future is under-estimated.

It seems though, that the future of computer graphics is actually Monte-Carlo estimated.

- Mikko Kauppila

PS: Hey, where are my favorite "there''s always the first-ray optimization!" posts?

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Wildfire: you should get much bether results actually, i think.

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Well, I don''t I don''t know if you''ve seen the new Realstorm Bench 2004 yet, but the scenes are pretty complex.

Here''s a comparison of my system and a P4 done with the result browser realstorm 2003 (the old one) provides:

resolution       320x180x32
shadows          yes
reflections      yes
anti aliasing    no
volume lights    no
depth of field   no


System           Athlon XP                P4


Frequency        2088 MHz                 2803 Mhz
Rating           2800+                    N/A

MMX              Yes                      Yes
AMD MMX Ext      Yes                      No
SIMD             Yes                      Yes
SIMD2            No                       Yes
3D Now           Yes                      No
3D Now Ext       Yes                      No

Ram              1024 MB                  512 MB


Average FPS      44.82                    33.74
Min              20                       14.08
Max              166.67                   125

 

So, I don''t think my system is performing that badly. Plus I think that''s a pretty good confirmation that AMD''s rating is pretty much valid.

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Wildfire: the nvidia demo is just a plain hack. there is nothing real usable about it. i hope you know that. (guess why the file is that big..)

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No, I didn''t know that. I''ve only seen their video so far, since I don''t own a GF-FX and can''t watch the demo.
I always wondered why nVidia''s demos (all of them) are usually >50 MB in size though. I don''t see any excessive use of high-res textures and the like that justify the size.

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and realstorm normally performs much bether than what Wildfire reports actually. You sound more like a 2000+ system. i''m still waiting for the first 3200+ a64 results.

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Well, it doesn''t. And my system is a 2800+ (2.08 GHz). At least this is what my bios and windows xp tell me. Maybe the above results from RS-2003 are more to your liking.

just disable softshadows. adrian told me you use them, i must''ve missed that. they are inherently slow currently, they''re working on that.

softshadows are in there merely to prove they are doable. they are by NO means done fast.

with standard settings, first test 2004, you should get very smooth fps.

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If that''s not the help you''re after then you''re going to have to explain the problem better than what you have. - joanusdmentia

davepermen.net

Ice-Age wasnt from Pixar or PDI though

If you want to do things stupidly you can slow anything down. When you work to get the best IQ out of your sytem you wont be reading back memory. System memory isnt all that much faster as AGP to begin with ... you cannot make extensible memory as fast as hardwired stuff (and you cant make hardwired memory as fast as embedded stuff for that matter).

Desktop CPUs designed for legacy software are fundamentally suboptimal for media-applications and games. As long as you keep one in the system and dont evolve it, all it will be is expensive dead weight in the end.

You can stuff 8 P4s or Opterons on a die, but on the same die you can put 10 times more area efficient cores with far higher peak performance (and with the kind of code we are interested in that advantage wont be lost in sustained performance either). Most of the hardware in a desktop processor goes into speeding up legacy serial code. They might have realised that diminishing returns have set in and combine a couple on a die, but that does not erase the fact that they use huge cores designed for serial code.

The DX-Next slides from meltdown mention an integer programming model for shaders and general I/O (ie. not just textures and 2D buffers anymore). With that the GPU is getting very close to being able to take up more than just the rendering tasks away from the CPU.

its taking them away, much too far away. thats my point actually. dx next sucks imho. they should start thinking about getting gpu and cpu to work more closely together, than to split them completely. that only means doubling of data. and doing work on the suboptimal system.

but i know that you won''t agree with me and i won''t agree with you pinky. we never got that near to each other anyways. not that your points aren''t true. i never implied that. but i don''t think they are good, and definitely not a good future.

the current way to do graphics on pc''s IS suboptimal. VERY suboptimal. just code at least once for a console system, and you know it. there, graphics and cpu''s are a team. they work together. on pc''s, they are fighting against eachother. when ever you need them to work together, you realise how slow they share their work. much too slow for any real advantages. the only way around this is to make the gpu do everything. but then, why do we need a cpu again? just put your hd and os onto the gpu and you''re done.

i prefer to start at the cpu system and make it evolve to get more simd and espencially mimd tasks done. this brings much more. more speed for physics, for audio processing, and much more. huge scene interpretation analises for ai, etc. a gpu can NEVER do that. a cpu can.

but its a worthless discussions, as we don''t design the future. big marketings do. and they push rastericing till the end. and then they will start hyping raytracing..

they never care about what is a good way. they only care about what way they can make big money. else, rastericing would''ve never been pushed that long that strong.

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If that''s not the help you''re after then you''re going to have to explain the problem better than what you have. - joanusdmentia

davepermen.net

oh, and just to have said it: we''re getting OFFTOPIC.

raytracing/rastericing has not much to do with how hw evolves. because good hw can do both. (with hw == cpu + gpu, no mather who does what:D).

oh, and, ApochPiQ, anything new yet? or do we still have to wait till december?:D

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If that''s not the help you''re after then you''re going to have to explain the problem better than what you have. - joanusdmentia

davepermen.net

quote:

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Original post by davepermen
oh, and, ApochPiQ, anything new yet? or do we still have to wait till december?:D

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December 23 is the official public announcement date. In fact I''m about to go start working on "it" in a few minutes

Unfortunately I must be forced to disagree with your analysis on GPUs vs. CPUs. I think the real problem is that people see fast GPUs and think "why not make the GPU do everything, since its faster?" This is a bit of a mistake because a GPU is, after all, a dedicated graphics unit. I doubt it would perform anywhere near as well doing, say, MP3 decoding, or running Windows software. The fact is, GPUs are gaining power in order to become better at graphics, not to become better at doing system functions. I think that for the visible future, for better or worse, the CPU/GPU decoupling is here to stay. As long as specialized applications can benefit from dedicated hardware, we will see decoupling. Only once a single integrated chip can handle all kinds of functions equally well will we finally get away from the CPU/xPU model and get into something more interesting.

Its also worth noting that, regardless of CPU architecture, you can accelerate raytracing far more effectively in dedicated hardware. CPUs will have to undergo a lot more changes than hyperthreading/K9 in order to catch up.

i don''t say dedicated hw is not bether suited for its dedicated task. but i say a coprocessor unit would fit our needs much bether. fpu was a dedicated hw long ago, too!

just think of it. buy a dual opteron mainboard, and now, instead of two opterons, you could put in one opteron and one dedicated nv30opt or r300opt. you could directly excecute pixelshader code on it, and all directly with the system memory.

there would be no cpu <-----------------------> gpu like today. you could do just what you want on the hw you want.

and i think, by supporting software rendering more, we can motivate hw to possibly think about coprocessors again. an spu secondary processor could help very much. and with the memory-management layout of the amd64 systems, they could work very closely with the rest of the system.

i just don''t think that split we do today, and we do even more and more, is good. gpu''s get more general purpose systems today. they have their ram, their management, and their near-to-os-capable chip on it. and still, sharing the information is terrribly slow.

i don''t say anything against specialiced hw. i only say something about the way we split it more and more from the rest of the system today. THAT is wrong. and THAT could be the reason software rendering could actually start to catch up with multiple parallel processors sooner as the gpu-vendors like to think.

just think of the software solution of openrt. they run today realtime on nice res on multpc-systems of 5-8 p4. connected over ethernet. if they could get a board with say 8 opterons at 2gig, or more (2.2 is anounced?), that will definitely help them to solve the current connection-latency and bandwith issues, to gain even more speed. on such a system, realtime raytracing completely in software is no problem. such systems are today available as highend. they will be, one day, available as homepc. the question is just, when. in 5 years for sure.

but actually, thats not the topic:D oh damn.. who cares?:D

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If that''s not the help you''re after then you''re going to have to explain the problem better than what you have. - joanusdmentia

davepermen.net

The point is that the desktop processors are suboptimal for every part of the workload which is computationally significant. They are relics, they will either evolve or be ignored ... sharing a workload always has overhead, unless the CPU becomes more efficient the overhead simply wont be worth it. DX-Next isnt about splitting them up, it is about cutting the CPU off.

Consoles are not extensible ... that allows them to get more bandwith between components, and allows developers to use a static work distribution with tightly intercoupled timing between components since there are no performance variations for each and every component. As such they are less reliant on a strictly one way rendering pipeline.

That kind of programming just doesnt translate to a system where all communication has to cross connectors and every component can have wildly varying performance.

MP3 decoding and running windows software are not computationally significant tasks compared to the amount of computations which will be dedicated to rendering on next gen hardware ... rendering, physics+collision detection and perhaps AI is what hardware should be designed for (and I think DX-Next is bringing GPUs closer to that goal, much closer than present CPUs). Other tasks I dont care about, if they run a little slower so be it ... they are insignificant.

[edited by - PinkyAndThaBrain on November 17, 2003 9:10:03 AM]

Realistically speaking: even if one has a raytracing solution that can shoot millions of rays per second, that''s still not enough, because you need to handle all the additional logic (sampling, exposure, brdfs, path tracing, bidirectional tracing, photon mapping, metropolis light transport, whatever!) in software, perhaps via a shader running on the RPU (ray processing unit).

Although the bottleneck would be removed, even the additional logic part is overly expensive for today''s CPUs, to be done per pixel that is.

So in the end, raytracing would still not be interactive if it were implemented on hardware. Hardware just doesn''t sell within consumer circles unless it gives realtime results on reasonable scenes, period.

- Mikko Kauppila