Batman Arkham VR - Fix Foviated vs. MRS
Batman Arkham VR – MRS vs. Fix Foviated and Pixel Density
Batman Arkham VR is an unusual game that immerses you into Batman’s world but doesn’t really involve fighting. It is a beautiful looking game with a lot of interactivity, and if you like “detective work” and puzzle solving, this may be the game for you. It’s short, but it really shows one what VR is capable of right now on the Unreal Engine.
Batman Arkham VR has multiple settings and its the only game that we are benching that takes full advantage of NVIDIA’s MRS and even offers a Warner Brothers in-house multiple resolution for Radeon users that they call “Fix Foviated”. According to Warner Brother Batman Arkham VR devs:
In order to achieve the high resolutions needed for VR, we take advantage of part of the human eye’s physiology, the fovea. This part of the eye is responsible for the sharp central vision we see and so we can focus our pixel density in a fixed central area of the screen, allowing the rest of the screen to be rendered at a lower resolution. The fixed foveated option of multi-resolution rendering does this by dividing the screen into two parts: a central circular high resolution region, and an outer lower resolution region. By doing this, we can achieve 90fps at foveated ‘virtual resolutions’ above the native resolution of the headset’s LCD screen as described in Pixel Density section above.
Here is the performance across six cards from the FCAT generated charts at 100% Pixel Density.
Let’s get a little closer look at the frametimes of the same graph.
The frames are generally delivered well with the exception of a couple of stutters that do not repeat in the same place for repeated runs. All of our test cards can play at the highest settings, but even with 100% pixel density, the scenes are slightly blurred and there is a minor screendoor effect visible. The holy grail of VR image quality (IQ) would be to increase the Pixel Density significantly, and we arbitrarily picked 200% to really put a strain on our cards so that we could compare “Fix Foviated” versus “MRS” performance.
Oh my, even the mighty GTX 1080 Ti goes into reprojection on the most demanding scenes. Fortunately ASW takes care to maintain 90 FPS which is playable in this rather slow-paced game. The graphics at 200% Pixel Density look spectacular in comparison to 100%, however. It is similar to using SuperSampling in PC gaming, and everything appears a bit sharper and aliasing in motion appears to lessen a bit.
Lets see if using NVIDIA’s MRS will allow us to have better performance at the risk of lowered resolution at the periphery.
With MRS, the GTX 1080 Ti no longer goes into ASW although the rest of the cards still do. Image quality is still outstanding, and the center of the screen where the action is, does not suffer any image degradation although there is a minor visual impact at the periphery. This editor would prefer to play with MRS on rather than go into reprojection, but it is also easy to decrease the Pixel Density in increments to find a good balance of performance and image quality.
Fix Foviated provides a higher level of performance in Batman Arkham VR than MRS, but at a higher cost of noticeable image degradation. It’s a trade off that allows the GTX 1080 to now play at 200 PD. And both MRS for NVIDIA and Fix Foviated for all cards, provide a good set of options to the player that he might use to get the highest settings and Pixel Density, with the least amount of image degradation and minimal latency.
Let’s look at Robo Recall and Serious Sam: The Last Hope next.