RESOLVED: Parallel Projection in Pitool’s setting needs to be ticked and this will go away.
Original Post:
Hi, I noticed an issue recently in the right lens where at the extreme edge of the lens, certain objects in the scene don’t render until you move your gaze and the object then suddenly appears as if materializing out of nowhere. I noticed this while in SteamVR home. I’m running Pitools version 1.144.
So if you imagine the entirety of the right lens as being 100 degrees, images and objects in the scene appear and render naturally as you would expect them to, up to about 95 degrees of the entire len’s FOV. But at the far edge where the remaining 5 degrees is, certain room objects will materialize and disappear out of nowhere, even though I can still see the background image. For example, if I’m inside the house facing the left wall, I can see the wall and shelves of the house all the way to the edge of the lens. If I’m looking straight at the wall in Steam VR home, the shelves with the personal objects is to the far right. But if there is an object that should be there like the cube or the unicorn on the shelf or the robot, it won’t appear until you rotate your view so that it moves into the 95 degree area of the lens. If it is at the 5 degrees of the peripheral edge, it suddenly disappears. The wall, shelf and background appear normally, but the object just vanishes when it moves into the 5 degree periphery of the lens. Then when you move your gaze slightly to the right the object then suddenly reappears as if materializing out of nowhere.
This can be disorienting when you look around the house as you normally would because objects pop in and materialize and as you turn the other direction, they suddenly disappear. It’s as if there’s a setting in the software that doesn’t trigger the object rendering until it moves into within 95 degrees of the lens FOV. Does anybody else have this problem? The left lens is fine and objects appear normally from the edge all the way towards the center of the lens FOV.
My system specs are:
i7 8700
16gb RAM
GTX1080ti
windows 10 pro version 1809
Gigabyte H370 Aorus Gaming 3 wifi
2tb HDD
960gb SSD
Can anyone please advise if this is a known bug and if there is a fix for it, or a setting that I need to adjust in pitools or steamVR to correct this?
I noticed it too, it happens only in SteamVR Home so probably a Steam realated bug, could also happen in some titles that were not conceived for such big FOV’s so the far edges areas at the sides are not rendered completely until they come more into view.
This is probably going to happen until more companies adopt wider FOV headsets like Valve just did (partially) with Index…
A rendering engine will create a view frustum that corresponds with that of the game camera (think kind of like the cone of vision a guard has in a stealth game), and uses this before it starts rendering each frame, to determine whether this or that object is visible to the camera at the moment; If it is not, it will be excluded (…or: “culled”) from evaluation, saving computing resources being wasted on animating them, setting them up for drawing, and so on, for no gain to the output image. (An object can also be occluded by other objects within a scene, as framed by the camera, but that is a culling stage of its own.)
It would seem that when the games in question calculate this frustum, they do not take into account the cameras looking slightly out to the sides, with HMDs that have canted screens, like the Pimax 8k/5k, and so fall short of the combined visible field of view of the viewer’s two eyes, even though it may have added together the outer view angles for each camera - just not taking into account that these are relative to each eye’s camera, rather than to the direction the viewer’s nose is pointing.
This mathematical oversight could occur in a number of different ways, depending on things such as whether the game shares a single culling frustum between both cameras (left and right eye), or culls them for occlusion separately.
Typically is seems we get “zero degrees” nailed down at the left edge (so things work fine there), and a miscalculated FOV added to this, so it falls ten or twently degrees short, at the right edge.
Yes this is definitely a matter of having Parallel Projection enabled. I hope we get this problem solved soon, and Im sure it will be, as Valve Index has basically the same need of Parallel Projection, caused by the canted panels. Maybe we will see an automatic SteamVR workaround soon. Lets hope!