I have been using a VR headset for a while now, and there is one thing i cant get over, and that’s the screen door effect. At some point in every game, and especially in videos I begin to notice this effect, it feels like there is a screen door (figure that!) between me and the action. So what causes this? And why is it more noticeable in some games than in others, or in videos for that matter?
Well, the screen door effect is caused by being able to see the space between the pixels in the display. Simple as that, spoiled the click bait a bit didn’t I? Well not so fast. The super simple answer to this, is just make the pixels bigger to make the spaces between them less noticeable. Sure that will help, but it will allow your brain to notice the pixels themselves more readily.
So how do we solve the issue of the screen door effect?
Well, perhaps the answer is to simulate an analog medium. The most reasonable medium that comes to mind to me, is 35 mm film. So how do we simulate 8mm film in a digital display? Well resolution of course.
So increasing the resolution of displays located in VR headsets should help minimize this effect, but what resolution will eliminate this effect? 4K headsets are on there way, and this will certainly help, but does not reach what will be necessary.
35mm film being an analog medium, does not have a resolution, but it does have a point at which it begins to break down, most sources recommend storing 35mm film at what amounts to 8k resolution. So do we need 8K resolution to eliminate the screen door effect? Maybe…
The screen door effect at the point we have 8K resolution monitors inside our VR headsets will no longer appear as a screen door effect, but rather as aliasing, assuming that 8K is the right resolution for us to view analog medium, a point of diminishing returns. So given this fact, how do you eliminate aliasing?
And every gamer jumped from their seat, screaming that every game made this century has built in anti aliasing. Which is true, almost every game has, built into its graphical settings an option to add anti aliasing. Anti-Aliasing works by up-resing the image in question, then down-resing that same image to display on your screen, basicly smoothing out the jagged edges. Of course this is all done digitally, within the motherboard. So how do we get this to work between our eyes and the screens. Well, more resolution of course.
By increasing the resolution of the screens inside your VR goggles, you can smooth out how your mind perceives the images, even if it’s unable to distinguish the individual pixels anymore. So where does this leave us, let’s assume we have 2x “anti-aliasing” on our 8k display, giving us the need for a 16k display, which is pretty insane in the grand scheme of things.
Currently the video ram requirements on a standard 2k equivalent VR setup such as an Oculus or a Vive are about 4Gb of dedicated video ram, rendering low level and most mid level graphics cards unable to play these games. While much of that video ram is taken up processing models, more than a little is take up by the textures needed to operate in this realm, and higher resolution VR headsets will require high resolution textures, and in turn more dedicated video ram.
The relationship isn’t direct, and data spotty, a recent test of battlefield showed that while about 2GB of Vram was consumed for standard 1080P gaming, 3 GB of Vram was consumed for 4K, and a whopping 8GB of Vram was used when rendering the game in 8k resolution. And these tests do not have the higher resolution textures that would be required to fool the brain in a VR setting.
So while I would like to assume that the theoretical 16k display used in our screen door eliminating, perfect reality simulation of VR would be able to run off two GTX 1080’s in SLI, likely there combined 16 GB of Vram, though impressive, would fall short of the tasks required. And likely we would need some monster machine unimaginable at the present will at least 32gb of Vram to pull this off.
So alas, while moore’s law says that we will likely be rocking these cards in a perfect VR setting in about 6 years, untill then I will need to settle for what I can get, and maybe that will allow us all not to get immediately sucked into the virtual world just yet.