'We want that the real-time images look indistinguishable from reality. We want them to look like a film.' Nvidia has lofty goals for path-traced graphics, but its support for Microsoft's shader stutter cure is a lot more interesting to me
At this year's GDC event in San Francisco, Nvidia took to the stage to tell game developers something that they, and anyone for that matter, already knew: future games will only have film-level graphics by 'fully leaning into AI to cross that chasm between what's attainable [now] and what's attainable in film rendering.'
Those were the precise words from John Spitzer, vice president of developer and performance technology (4:51 mins into the above video), when describing Nvidia's ambitions for path traced graphics in games. But as anyone who has tried using said rendering feature in the likes of Resident Evil Requiem, Doom: The Dark Ages, and Alan Wake 2 will know, path tracing comes at a seriously hefty performance cost right now.
In fact, there will always be a high price to pay, because there are no shortcuts to achieving what Nvidia is targeting for games. "We're still not to where we want to be. We want that the real-time images to look indistinguishable from reality. We want them to look like a film."
The fact that we can even use path tracing now is down to the use of ASICs (application specific integrated circuits) in our GPUs, namely RT cores, that do nothing but accelerate calculations for ray intersections with triangles and figuring out which object a ray has hit out of the tens of thousands in a scene.
It's also down to the use of upscaling and frame generation, the former for lowering the performance hit, and the latter for creating additional pixels to bridge the gap even further. AI is used heavily in both, as things currently stand, so it's only natural to expect that Nvidia is going to leverage it completely to reach a future where the path tracing performance relative to a Pascal-era GPU is a million times greater.
We've already seen elements of what Nvidia has planned, such as the new RTX Mega Geometry foliage system and DLSS's 6x frame generation mode, so it's fair to say that we'll probably see an even bigger focus on RTX and DLSS tech in the coming years. However, most game devs aren't really interested in what's to come five or more years down the road: they're being paid to work on projects now.
To that end, Nvidia has announced two specific things that should help make an immediate difference, whether path tracing is used or not. Both are official support for DirectX features that Microsoft has been promoting: an API for shader-level machine learning with a specialised compiler, and more relevant to any PC gamer, a pre-compiled shader delivery packaging system, called Advanced Shader Delivery (ASD).
We first learned of ASD back in October of last year, though the system to help wave goodbye to shader compilation stutters and other woes was only announced for the Asus ROG Xbox Ally family. However, Nvidia says it is "collaborating closely with Microsoft to bring ASD to GeForce RTX users later this year."
What exactly this will all entail is anyone's guess at this point, but I suspect that Nvidia will work with Steam, Epic, and other digital distributors to support ASD in a selection of GeForce/RTX-promoted games, once the system is ready for public release. The good news is that AMD, Intel, and even Qualcomm are fully on board with ASD, so even if the first use cases are quite restricted, it shouldn't be too long before we see it being implemented in all big game releases.
I dare say that while path tracing is very much going to be the main focus for Nvidia, the majority of PC gamers are going to be far happier to just have games that don't take forever to load, because they're busy compiling shaders, or don't stutter like crazy, because they're compiling during gameplay.
To be frank, Advanced Shader Delivery can't come soon enough.