Ray-Tracing, meaningful performance metrics and alternatives? *spawn*

Discussion in 'Rendering Technology and APIs' started by Scott_Arm, Aug 21, 2018.

  1. JoeJ

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    uuuh... i remember imperfect shadow maps / many lods papers proposed just hacky solutions for this as well. :(
    I have a better solution and Alex Evans might be interested in discussing this. (I would just share it - i need some contact to game industry anyways.)
    How could i approach him quickly? Filling out a job offering form on MM website? Creating Twitter account and send him PM? Would this work?
     
  2. Shifty Geezer

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    You might have a better solution, but newbies talking to top-of-the-field experts saying, "I'm better than you," never goes down well. A tweet will likely be read but as an unknown with no prior and no links to a blog that's been showing pioneering tech etc., you'll probably get overlooked in all the noise. Open discussion about tech will not be patentable and ideas are generally shared freely to advance the industry.

    You need a demo. You then need to work hard getting anyone to even look at your demo. If it looks unbelievable, you maybe lucky and get plenty of attention from industry vets calling it out as BS. But eventually you'll get attention, and then you can try and do something with it, either starting a company to license the tech (Euclideon "Unlimited Detail" which has ended up in arcade machines), or securing gainful employment with a dev or engine.

    I recently watched a film "The Man Who Knew Infinity" on Netflix, about a nobody Mathematician from India who far excelled his peers in ability, but of course no-one would listen to him. He had to slowly prove himself (and died from TB before he ever had the chance...). Having an idea is a tiny part of getting anywhere. It's far more about salemanship and making noise. There are plenty of folk who have done well with just salemanship and making a noise without any meaningful inventiveness, and many, many great ideasmen who've faded into obscurity unheard.
     
  3. chris1515

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    And another things, Alex Evans did not work on the rendering part for the last two years, he was working on the audio part(audio tools). Simon Brown was refining the rendering part and I think they used raymarching cubes mix with point splatting because it was used in one of the failed prototypes.
     
    #683 chris1515, Jan 3, 2019
    Last edited: Jan 3, 2019
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  4. Scott_Arm

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    There are a lot of devs on twitter and they respond to questions etc. Probably the easiest way to share and talk about stuff.
     
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  5. manux

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    The devil is in details. A lot of ideas get discarded due to details or practicalities. When you have team of hundreds of people needed to create triple a game the constraints are very different than a lone wolf doing tech at home. There is a lot of inertia from existing solutions and changes happen slowly. Especially when things need to ship on certain date for the company to make money.

    I wonder if ray traycing could gain popularity on the artist productivity benefit alone even if some performance was lost along the way.
     
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  6. iroboto

    iroboto Daft Funk
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    nailed it!
    I just want to second this commentary, in that if you really want to be profitable off these concepts, you need to expose them fully for criticism and peer evaluation. Value of the technology is _not_ in the technology itself, but the experience you own in developing it. This is why certain studios/teams are allowed to be continually funded, because of the expertise and knowledge they have in the field is worth more than the product itself. That is where your worth is. If you hang onto the idea alone you miss the part where it's execution that makes a great product, and to execute well you need the experience of others in the field that have executed a great deal to see where your product may not address the core concerns of other developers.
     
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  7. JoeJ

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    Ok, thanks for all this, guys! Makes sense and is not so different to the industry that i come from.
    Working hard on the demo, and the rest will then will be hard too... :)
     
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  8. OCASM

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    The fact is we haven't seen anything from Dreams that can rival the best of the AAA space in terms of fidelity. All they've shown are very small limited scenes. Also, NVIDIA experimented with a fully programmable rasterization pipeline a few years ago and it turned out to be an order of magnitude slower than the fixed function pipeline.
     
  9. chris1515

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    Another things after Claybook annoucement, Alex Evans said it could have been an interesting solution to try go full compute raytracing but I think they did not have the time to try it.

    EDIT: It was compatible with the user created content approach unlike current rasterization hack...
     
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  10. JoeJ

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    Really a matter of opinion. They can do many things impossible for Call of Duty and the other way around. But we will never see a fair comparison:
    Dreams has no occlusion system. CoD has Umbra or something.
    User generated content <-> professinal artists
    Both have completely differing visual goals.

    Likely they did triangles?
    The point is: Splatting a pixel is just a single atomic op. Try do render that many points by drawing a triangle for each. Would this make sense? No, and the same is it the other way around.
    Dreams has proven it can fill the whole screen with individual points. One could add PBR and occlusion culling without issues.
    Do you think we need HW triangle rasterization forever, although filling the screen is no longer our primary performance problem?
    If so, why do you think NV does such experiments at all? Maybe they prepare for the upcoming need to emulate it?

    I mean, we're really offtopic now and likely there comes up a threat about Dreams. Also i'm not one of those who want to see replacements for triangles. But it IS a good example of how FF HW becomes always questionable at least after some time.
    Claybook is another. Performance is jaw dropping. And you could add stuff to this as well...

    Hmmm... would this make cone tracing easy? I don't like raymarching, but i want cone tracing... i need to think about this...
     
  11. OCASM

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    Sure, the Dreams approach has its benefits but lets not pretend it doesn't have a huge cost.

    Maybe NVIDIA did the experiment to prove how important fixed function is for performance :p
     
  12. JoeJ

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    Hihi, sure! So that's why they ended 10x slower ;)
    But seriously - why would they want to, having the lead in HW rasterization? No no, wait 10 years, and then they will say: "We have 10 years of experience in removing rasterization HW. See our new invention: SSS 5080 Ss" :D
     
  13. Shifty Geezer

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    I didn't reply before this thread is getting way OT and I'm not sure how to manage it, and wanted to avoid more noise. Dreams has shown large levels in races. We also know the maths of SDF means levels can be huge. If they are constrained in Dreams, it's likely a design choice so users aren't overwhelmed.

    What costs? The main issues voiced so far has been lack of tools. We need the game to compare performance.
     
  14. OCASM

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    You never know.

    Where's the footage of those large levels? If proof is presented I'll concede the point.
     
  15. DavidGraham

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    I just tried the "Insane" SSR reflections in Gears 4 on my 2080. @1440p Ultra graphics, my fps got slashed instantly from 102fps to 60fps! And for what? Insane just expands the number of reflected objects, and the number of affected surfaces, it also increases the resolution of reflections and tries to simulate them in water in a realistic way. Nothing earth shattering, and they are still SSR.

    Worse yet in areas with a lot puddles I can't maintain 60fps locked @1440p! Meanwhile I can do 1440p60 @Ultra DXR in many areas with heavy reflections in Battlefield's Rotterdam map. This just shows how much rasterization has reached a blockade in terms of extracting image quality from a given performance target. Many effects just exert a massive toll on the hardware without a proportionate increase in IQ.
     
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  16. eloyc

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    In their Twitch channel you have most of their videos: twitch.tv/media_molecule

    Now I don't have the time to watch them all again, but I think that in videos such as World Building, Little Big Planet and Made by the Molecules you can find relatively big levels, such as the asteroid game. Also, there are videos where they begin with a little area, then zoom out a lot and start pasting that same area over and over again to create a huge area, and they do that without apparent slowdowns.
     
  17. Shifty Geezer

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    Unless the track is a tiny loop, it has to be a far bigger level. But as I said, even if levels in Dreams are constrained, that doesn't mean the tech is.
     
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  18. troyan

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    There is a huge penalty from activating DXR even on maps like Hamada which has only a few reflected surfaces. It takes twice as long to render a frame from "off" to "Low" (200FPS -> 100FPS), yet there is no real difference between "Low" and "Ultra".
    That can explain the "small" difference between Volta and Turing.
     
  19. OlegSH

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    The same can be seen in Unigine Superposition benchmark with Extreme quality setting, which enables ray tracing with large search area and probably a few samples per pixel in screen-space for global illumination and reflections.
    With AO, you can go away with simple Monte Carlo integration for random samples inside of relatively small hemisphere (in screen-space area), which is still quite friendly with caches (especially if search radius is small). But you can't do the same with GI and reflections, raytracing is required here and searches across large areas of screen will certainly trash caches and bring performance down (you can see how Volta and Turing with fast and large caches are much better here)

    Perf drop in GoW with "insane" preset is insane indeed - https://images.nvidia.com/geforce-c...ar-4-screen-space-reflections-performance.png
    And it seems the main difference is that "insane" reflections are proper stochastic reflections with a few rays per pixel - https://images.nvidia.com/geforce-c...teractive-comparison-002-insane-vs-ultra.html
    while other presets implement perfectly mirrored ones with 1 and lower number of rays per pixel
     
    #699 OlegSH, Jan 4, 2019
    Last edited: Jan 4, 2019
  20. AlBran

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    If we're willing to give RT the benefit of the doubt in terms of a future of optimization & iteration, it would only be fair not to judge this 2 year old implementation of SSR, which is seemingly rather brute force (it's also Unreal Engine 4 *ahem*), and whose existence may have stemmed from exposing the settings/path they used for the cinematic recordings, where performance is not the impetus.

    It's also worth considering that Gears of War 4's development was extremely rushed - MS bought the IP in early 2014, and Coalition had to create the game on console and then try and support the rather finicky variety of hardware on PC for an October 2016 release, so we could guess between 18-24 months of development while starting from scratch on a *redacted expletive* version of UE4. If you notice while playing the campaign, it's rather apparent how inconsistent the quality of graphics can be across the levels - the implication being that they were learning the engine as they went along.

    It's a rather suboptimal situation when we have evidence of the various PC issues over the past two years, a couple of which still have yet to be fully resolved on nVidia's side.

    So it's not a great example. :embarrased:

    /DevAl's Advocate :p
     
    #700 AlBran, Jan 4, 2019
    Last edited: Jan 4, 2019
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