NVIDIA will hate this!

Haha okay, I know when I'm exaggerating. But still.

The magic is almost ready for release. So, even if I'm no good when it comes to recording videos, I wanted to show you a brief clip of what's about to drop.

As you can see from the info near the top of the mod overlay, I recorded this on a Quest 3 and RTX 4090. I used DLSS set to Quality, and set the pixel density to 30 ppd (pixels per degree). That turns out to be a pretty high display resolution of 4736x4912, or a rendering resolution of 3157x3274 before the DLSS upscaling.

AER v2 is set to its default value for Cyberpunk 2077, which is 1/3 rate. Since I run my Quest 3 on the recommended 72 fps, to lessen the VR load on the GPU and give some breathing room to the video encoder, that means the game is locked to 48 fps (72 x 2 x 1/3).

What I want to show you however is the increase in fps that you'll get from the new optimizations, so the first thing I do at 0:27 is turn on a new functionality I expose in the mod, which I call "App freewheeling". Ticking this box allows the game to run at the maximum frame rate it can sustain, not being limited by the speed at which VR refreshes. Basically it's like "vsync off" for VR.

Note that I don't recommend actually playing the game with App freewheeling turned on, because it will lead to jerky motion and possibly some reprojection issues. It's mostly a measuring tool, to let you see exactly how much overhead you have once your VR frame rate is locked.

After toggling it, in the video I get about 61-65 fps.

Then at 0:42, I turn on the first optimization (for vertical field of view, or VFOV). This is a safe one, and it will automatically be available for all the games in our collection of VR mods. At the moment I implemented it against the Oculus runtime, so it will work on the Quest family, but assuming that testing goes well, in time I will port it to other headsets.

As you can see at 0:45, when VR reconnects, some magic has indeed started to happen. The headset is still displaying at 30 pixels per degree, but now the game only needs a final upscaled resolution of 4736x4032, that is a rendering resolution before DLSS of 3157x2688. That means 18% less pixels to draw, which is reflected in the fact that the game is now running at 76-79 fps.

As I was saying, this vertical FOV optimization is completely safe, meaning that it should lead to no artifacts or compatibility problems with any game. In fact the image looks exactly the same, not just in the captured video but also in the headset itself.

But I want more []-D

So at 1:10 I turn on the horizontal FOV optimization (queue evil laugh sound effect).

When VR starts again, it's the same level of detail... but with 3696x4032 resolution, corresponding to a rendering before DLSS at 2464x2688. That's 36% fewer pixels than in the original implementation, and the frame rate is now touching 100 fps, about 55-60% more than the initial 61-65 fps.

Now, there's a couple of caveats. The most important being, the horizontal FOV optimization won't automatically work for all games. It is prone to artifacting (like for instance duplication of some HUD elements), which means that every new game will need to be tested and if possible fixed to become compatible with it. But when it works, it works wonders !

The next mod release will implement it in at least two games, namely Cyberpunk 2077 and Watch Dogs 2. There is also a new game on the way, dropping very soon (!), but for the moment it won't support HFOV optimization, only VFOV.

I made a lot of other improvements to the framework and to selected games, but this post is too long already to talk about them. Stay tuned for the next releases!!!