Metro Dev: Ray Tracing Is Doable via Compute Even on Next-Gen Consoles, RT Cores Aren't the Only Way

Ben Archard, Rendering Programmer 4A Games said that ray tracing is doable via compute, probably even on next-gen consoles. Specialized cores such as those featured in the NVIDIA RTX graphics cards aren't the only way.

[codelyoko]

Once again NVIDIA with its closed technologies will lose. Open standards FTW.

[abstractel]

AMD have been working on their own dedicated cores that are faster at calculating raytracing and other things. There's no reason why next-gen consoles won't have these cores (only cost is a factor, but we are looking 1 1/2 years ahead and Sony's consoles always launch at a loss for the company).

And that raytracing is possible without RTX cores shouldn't surprise anyone. People have been showing it for years in technological demonstrations. The RTX cores are just really good at speeding up these calculations. Denoising has also come a long way which is essential for real-time raytracing to look good.

[Razuel]

this has me thinking that it could be a feature of a pro model.

[Bladesfist]

There is no closed tech here, the RTX cores are really simple bits of hardware and they just use hardware accelerated DXR which is a Direct X standard. DXR can and will fallback to regular compute but the performance is much much worse.

In fact RTX cores are just a gamer version of the names of the same cores in the workstation products.

I understand attacking things like GSync for being closed and proprietary but this is just Direct X plus some specialised hardware to speed up some otherwise slow tasks.

[starchild]

I agree. At least Nvidia is often the one moving these technologies forward. I feel like some people just have kneejerk tendency to attack Nvidia even when it makes no sense. Yes, they sometimes create proprietary technologies, but that's part of the way the stay profitable. I don't condemn companies for trying to be successful.

Even Gsync is nothing I criticize them for. They brought a new technology that was transformative for my PC gaming. And I was able to enjoy it before it would have ever been available elsewhere. It was worth every cent I paid for it. I'm no Nvidia fanboy though. I've owned plenty of AMD parts over the years.

[ProjectVulcan]

Nice post, exactly spot on. It's not that you CAN'T do ray tracing without specialised hardware, but it's usually much, much, much slower if you don't have it.

So you won't do it.

Unless next gen consoles have specialised hardware acceleration for it then they won't use it, at least in the majority of games. Console performance is always about compromise and if an effect is inordinately expensive (i.e slow) it is rarely used, or used extremely sparingly.

AMD don't have the technology incorporated in any of their upcoming GPU architectures, and so it is extremely unlikely next gen consoles will utilise it. It'll be much later in 2020 before AMD do anything along these lines, even on high end desktop.

This article backs up these projections about next gen consoles:

https://wccftech.com/amds-d...

[VariantAEC]

@ProjectVulcan
Special hardware isn't required either.
Just more powerful hardware than what's on consoles now and far more refined software execution.
CUDA cores already handle raytracing but the software was designed for different hardware hence RT cores. Could they have just made the software more compatible with CUDA its possible but not likely because CUDA (Compute Unified Device Architecture) was always made for parallelization specifically to render clusters of rasterized computer graphics, but parallel compute is obviously useful outside of just rendering pretty games.

Anyway I'm sure the RT cores are even more adept at sorting calculations by importance for the purposes of parallelization of massive numbers of calculations. These kinds of sorting algorithms for the purpose of path tracing were made by Disney (and likely Pixar) to speed up the render process. Oh and I'm not joking about that... Video Source: https://youtu.be/frLwRLS_ZR...

Ray tracing can be achieved on a modified pocket calculator.

[Timesplitter14]

Well, no rendering tech (like RayTracing) is ever exclusive to a certain hardware. You can program raytracing on a CPU chip from the 80's if you'd want to, and you can easily program raytracing on today's non-RTX GPUs (takes about 2 days to do if you kinda know what you're doing).

You can even make one in MS Excel: https://www.youtube.com/wat...

But... it's just that it won't be nearly as efficient as it would be on specialized hardware. And that means it often won't be a viable option unless you want your game to look like a powerpoint slideshow

[KaiPow]

But at what performance cost?

[OpenGL]

This is the issue, sure you could do real-time raytracing on the shaders but there would be a substantial performance penalty. Currently all the RTX cards have discrete hardware for accelerating ray tracing, I would not be shocked if these disappear in a few years and the shader design instead incorporates the hardware features, much in the same way GPUs once had discrete pixel and vertex shaders.

[ccgr]

Still have to see RTX for myself

[Alexious]

You'd need an RTX 2060 at least.

[ccgr]

I have a 2080 but have yet to play the bundled RTX enabled games ;)

[Father__Merrin]

Could you imagine if amd released new drivers that turned on rtx effects equivalent across all its gpus for free

[LightofDarkness]

You'd have to massively sacrifice performance in every other area in order to allow that. It wouldn't be worth it or be close to Nvidia's offerings.

[sinspirit]

That remains to be seen. AMD cards have a lot of raw compute power even compared to NVidia. The potential is if they could take advantage of it for raytracing. I doubt it unless the software has a specific AMD attuned code. I think AMD should allow a second GPU to handle it if you'd like, similar to NVidia with PhysX back in the day

[LightofDarkness]

AMD's compute power comes from every GPU core being available for compute or graphics, i.e they're heterogenous. There are no "extra" cores available that wouldn't already be in use, meaning you have to divert power from some other aspect of rendering to devote to RT.

[babadivad]

You already have to do that with Nvidia cards.

[sinspirit]

@LightofDarkness

That still means more compute power. I'm not saying they could compete or do better than dedicated cores. It would simply be interesting to see software take full use of them the way Vulkan does.

[Bladesfist]

Not today, maybe for a future line of GPUs. It will require either dedicated hardware or a ton of extra compute power.

[Cybermario]

interesting, so people with amd cards wont miss out, wonder how much the cost of home cosoles will increase though

[Bladesfist]

I doubt they will bother adding all of the extra compute power or dedicated hardware for this, it's too expensive, maybe if they release low and high end consoles at the same time or maybe with the pro versions of the new consoles in 5 years or so.