Per aspera ad astra

[Important correction: version 19.0.2, attached at the end of the post, actually delivers what I was talking about regarding Higher quality AER v2. I apologize: I made a packaging error in the previous release, which meant the new algorithm was working correctly only on my machine. Again, the difference is not night and day, but I recommend that everybody update because the haloing artifacts should now be visibly reduced on all NVIDIA systems. Also, this revision fixes the missing player health bar in Far Cry Primal.]

I'm sort of getting carried away with these Latin citations, aren't I?

So, this is a surprise update... even for me. No kidding. If you had asked me just a month ago, I would have said that I would not be working on this, at least for a year, and maybe not even then.

But I got a LOT of requests, so I finally gave in. And now I must say: I'm glad that you kept asking and pushing me, and I'm very happy with the way things turned out in the end.

It's still early times, granted, and even an RTX 5090 will sweat bullets running this in VR. So in a sense it's kind of like a tech demo that you can experience if you want to take a peek at how games will look in a couple of years, for those fortunate few who will have the boatloads of money and the PR connections needed to lay their hands on a next-next-generation GPU. But in another sense it is very R.E.A.L. ^_^, and you can use it even now to play complete games, provided that you are willing to accept a few compromises with the graphics options and the resolution.

OKAY WHAT IS IT? Even the most patient amongst you are now asking. Ah sorry, did I forget to tell you?

I fixed Ray Reconstruction for VR. []-D

You will now be able to use NVIDIA's hardware/AI powered acceleration for path tracing in any game you fancy, provided that the games you fancy are Cyberpunk 2077, Hogwarts Legacy, Indiana Jones and the Great Circle, or Star Wars Outlaws. At the moment, a grand total of 8 games (!) support this new technology (see https://www.nvidia.com/en-us/geforce/news/nvidia-rtx-games-engines-apps/ for the full list), and half of them are in our R.E.A.L. VR collection.

But I'm pretty sure more will come, both new and old titles. Ray tracing is here to stay, and after seeing it in action in VR, despite the hardware limitations and the compromises needed to run it at a decent, consistent frame rate, I have to say that it does look mighty sweet.

Also, it grows on you. At first you are likely to see it just as a gimmick. Oh wonderful... accurate reflections, so the game will look better when it rains. Who cares! But after a while you start appreciating all the tiny details, the subtle improvements that together contribute to make the virtual world and the characters in it more realistic and credible, and when you turn it off suddenly everything looks flat. I mean, not "flat" flat, because we're still in VR. But flatter and a little dull. And that's when you'll want to be able to push that magic button in every game.

Well, we have four now. That's a start :-P

I called this new fix DL(S)SS-RR, because who says acronyms must have a finite number of letters? NVIDIA and the game engine developers do most of the work, with 6 letters out of 7: the Deep Learning Super Sampling Ray Reconstruction part. I quietly sneak in the (S)tereoscopic addition.

All 4 games available now really shine (pun intended) with this technology improvement. Star Wars Outlaws can at last be played without the disco-lights effect on every surface that its normal (and compulsory, grr) ray-tracing denoiser exhibits. Ray Reconstruction stabilizes the image perfectly, and the lighting is solid and believable. Hogwarts Legacy looks MUCH better with ray tracing, and the shimmering that was still present for example on vegetation even with the DLSS fix is completely gone. Cyberpunk 2077, as we all know, is a game that seems to have been specifically designed to show off this new tech. Neon lights everywhere; reflections on cars, pavement, and futuristic clothes; bright colors; 'nuff said. Indy is perhaps the most understated of the four titles, with many levels taking place in semi-dark non-reflective environments where the improvements brought by ray tracing are subtler; but it also has its magic moments, and for example the initial level in the huge college rooms with glass everywhere is truly a sight to behold.

DL(S)SS-RR will activate automatically when needed, but as usual with my mods if you encounter problems with it you can turn it off from the game-specific tab of the mod overlay, like for instance the "INDY" tab for Indiana Jones and the Great Circle. There is a single checkbox that controls both kinds of DL(S)SS fixes (the previous supersampling one and the shiny (haha) new one for ray reconstruction), because they are mutually exclusive anyway. Meaning, a game can't use both at a single time: when you turn on Ray Reconstruction in the game settings, the mod will automatically switch from DL(S)SS for SuperSampling to DL(S)SS for Ray Reconstruction.

Speaking of Indy, this release also works around the driver issues that made the game crash when playing with DL(S)SS active on an RTX 50xx series card. I know that many of you have been waiting for this to finish your playthroughs; sorry that it took me so long to identify the problem and find a trick to sidestep it.

Unfortunately the latest few NVIDIA driver versions have been plagued by regressions, crippled functionality and even BSODs. If you have a powerful card and want to try out Path tracing with Ray Reconstruction, please be advised that you are quite likely to stumble into driver problems. They might manifest as checkerboard patterns, flashing lights in one or both eyes, super-grainy and noisy images, you name it... and you can immediately tell they are driver problems because once they start they persist through different game sessions until you reboot the system.

If you fall victim to these issues, I only have three remedies to suggest: first clear the shader caches, both the game's and the driver's; if that's not enough, reboot; and if even that doesn't fix it, try to downgrade or upgrade your drivers until you find a version that works acceptably with your card. At the moment of writing, I'm running my RTX 5090 on 572.83 and can usually "fix" any weird issues by clearing the shader cache.

Higher quality AER v2

Besides the flashy new stuff on which I shared my reflections above (OK I'll stop now, promise), version 19.0.0 of the R.E.A.L. VR mod also introduces a new, more accurate optical flow estimator for AER v2. The checkbox to turn it on is in the main page of the mod overlay. It's not switched on by default because it's more taxing on the GPU and older cards might fail to keep a steady frame rate when it's activated. Your feedback as usual is very welcome.

Don't expect a night-and-day difference. It's actually a very subtle improvement, mostly intended to make the AER v2 fringe artifacts smoother and more regular, rather than to get rid of them altogether. Unfortunately the artifacts cannot be completely eliminated on current hardware because the optical flow estimation the card provides is simply not good enough. But for me this improvement does the trick of making my brain more tolerant to the defects, which is all I can strive for at the moment.

Frame generation

Pre-emptive answer to the questions that will surely come. No, sadly frame generation cannot be used in VR. And it's not one of those cases where I say no and then start hammering on it for weeks until it finally becomes workable. Frame generation is not for VR because NVIDIA doesn't want it to be.

While DL(S)SS happens in user space, and the upsampled buffers are given back to the game so developers can do what they want with them, with FG the interpolated frames are kept hidden in the driver, and they never make their way back to the application. When it's time to present them, the driver sends them directly to the monitor (which makes it impossible to even record them for replay and analysis without specific hardware capture tools), and the game doesn't get any information about the precise time the frames were presented, let alone the contents of the buffers.

VR headsets are basically screens with accelerometers and lenses, but despite that they are not seen by the driver as a generic screen, due to engineering decisions taken by Oculus, Valve and the IHVs in the early days of modern VR. So, frame generation doesn't take VR headsets into account, at all. If you were to employ FG on a VR conversion, and for some lucky combination of events the hack didn't crash, all you'd get would be smoother motion on the monitor display with increased GPU usage, but no extra frames at all in the headset.

That is not going to change until NVIDIA reverses their policy on not making the generated frames available to developers, and frankly I deem such a reversal exceedingly unlikely. The only scenario in which NVIDIA could reconsider their decision is if there was huge demand for the feature from gamers, and that won't happen because flat games don't need access to the interpolated frames.

Far Cry 4

Finally, this version restores VR functionality for Far Cry 4 after it had been broken by Ubisoft's nude/not nude/actually nude again series of updates, in which they apparently took advantage of the confusion to sneak in an undisclosed anticheat watchdog that triggers even when you play completely offline. Uncool, Ubi.

Play it now

Actually, the Far Cry 4 thing makes me want to say something I've been thinking for a while. If you like these games we now have in VR, don't wait: play them today, while they're working well. The exhortation is also meant for myself; I've been spending too much time modding, and precious too little time playing, in this last year.

There is no telling how long we'll be allowed to play these titles. Microsoft has killed its WMR technology completely. Apple has stopped production of the Vision Pro. Sony is doing very little to keep the PSVR 2 ecosystem alive. NVIDIA is no longer mentioning VR in any of its products, and their latest generation of developer tools actually errors out if a process has been marked with the VR flag. I don't want to end the post on a sad note, so let's just say this: if you want to enjoy these games in VR, from start to end, with the titles working properly and without jumping through crazy hoops... the time is now.

Carpe diem!