- This topic has 17 replies, 3 voices, and was last updated Feb 27, 2018 10:04am by
.
-
Posts
-
Hello, I have an issue when using DirectVR where the virtual screen is about 1/8 screen too high, and 1/5 screen too far to the right. It’s relatively subtle, but makes the games unplayable (tried Skyrim and Chivalry Medieval Warfare).
The easiest repro is to zoom all the way out with Shift+Zoom and notice the screen is just literally not centered.
Since the screen is fixed to goggles / camera position, I’m perpetually looking at a skewed plane and there’s no way to get it “flat” and un-tilted (very frustrating and headache-inducing). I’ve tried Alt+Space in lots of places, and successfully ran the “scan” with Alt+L, but nothing has fixed it, and I’m giving up for the night. I don’t have an issue with regular SteamVR games so I know it’s not the headset / mounting on my head. VorpX is attaching the virtual screen in an off-center position!!
Any help is appreciated
-JamesTo gain a few extra pixels where it counts VR headsets use an asymmetric view frustum that takes into account that humans see better downwards than upwards. Normal games on the other hand work like photo cameras and render exactly one half up- and one half downwards. The vorpX camera is lined up perfectly with the game camera. When you zoom out it may seem like it’s not because your headset renders more in the bottom “half” of its view than the game does. Moving the image down would cause distortion when you rotate your head while being zoomed in fully since the vorpX camera center would not point exactly at the game camera center anymore.
Hopefully that doesn’t sound too confusing, the bottom line is that everything is as it has to be.
On Vive however something else comes into play: vorpX per default doesn’t use the full screen vertically on Vive but instead shows the same vertical field of view as a Rift, which is bit smaller. Most people can’t see the bottom screen border on Vive which makes this an useful optimization to gain a sharper image. If you want to utilize the screen fully, you can raise the image zoom (image page of the vorpX menu) above 1.0. Be careful though, doing so will reduce the image sharpness since the same amount of rendered pixels has to cover a larger area on the screen.
For Rift users reading this: the above paragraph relates to a Vive specific optimization. On Rift image zoom 1.0 fully utilizes the screen, so you don’t have to worry that 1.0 is the max value on your device.
There’s a small chance vorpX was misbehaving for the moment, but nothing that a “recenter” hotkey or game restart couldn’t have fixed. I only say this because on rare occasion I’ve encountered a similar off-center screen slip – when switching back to fullVR from a drifted edgepeek. Unlikely.
1/5th screen right sounds dramatic for an improper headset fitting, but thought I’d mention how my headset does not rest perfectly angled, so it puts centered crosshairs feeling a bit high and slightly left according to my vision. This ins’t noticeable in standard VR apps when there’s no centered reticles (range is free aim with motion controls).
While this sounds unlikely your problem, I wanted to mention just in case how I’ve found cinema/immersive screen mode useful for this. In those modes the screen isn’t glued to your face, but rather floating in front so your neck can control the viewing angle toward your own perceived center. These modes can introduce slight distortion, but ultimately feel more comfortable to my eyes. Doing this will reduce headtracking functionality however, something I prefer to do with a mouse anyway.
Maybe one day vorpX will allow us to toggle lock our preferred viewing angle toward the immersive/cinema screen, letting headtracking function as it does in fullVR. It sounds a bit redundant sure, but perhaps an answer for those asking for a way to realign the center.
Hopefully a reboot has solved your problem.
As stated above doing that would introduce image distortion when rotating your head since the vorpX camera center and the game camera center would not be aligned anymore vertically.
The very first internal vorpX version with headsets that use asymmetric view frustums did that. You can trust me when I say you wouldn’t want it to be that way. It results in a fisheye like distortion while rotating your head similar to using a wrong FOV. If such an option would make sense, it would have been introduced a long time ago – if only to spare me having to explain this matter every two months or so. ;)
I’ll consider an up/down option for cinema/immersive screen/edge peek mode where you can look around the screen, but for view-locked (“full VR” like) display of any kind it just makes no sense and would actually be a severe bug.
I messed around a bit trying to fix things, but nothing ultimately worked. The closest thing to a solution was the “Show expert settings” and “Camera height” which helped with one aspect, but not others. If there was a “Camera left right” adjustment I think it may work fine, but may also need Camera tilt up down or pivot left right.
I feel like there’s an arithmetic problem where the default camera is cast to the right eye, and the left eye just gets a new camera, rather than having both cameras equidistant from the center. This makes sense for 2D crosshair or overlays to be accurate for the right eye, but it’s pretty confusing. I may need a mod to shift all UI positions, because the health bar, top bar etc are just not actually horizontal, but tilted away from me on the right side
Pretty much, my camera is not lined up with the goggles. It’s possibly lined up with the right lens (I close my left eye and try to judge the picture), but its hard to tell. All I know is that the screen is too high and too far to the right, so the plane is tilted and right side is farther away.
Also worth noting that the screen seems slightly rotated clockwise or counterclockwise, but this might be part of the camera height adjustment which is why camera height looked much better when my view was from the center of the screen. Overall, just slightly enough off-center that it’s confusing for my brain, and I think it has to do with arithmetic and shifting of camera position / angle.
The center of my actual room-scale is on my right side as well, I don’t know if that could be useful for finding a bug in the code. Just seems weird that I’m the only one who has this issue too zzz
Did you read the explanation in my reply? It may *seem* to you like the camera is too high, but it is not. You get this impression because of the asymmetric view frustum of the headset which renders more downwards than the game does. The vorpX camera center is perfectly aligned with the game camera center, which is like it has to be. Both have different view frustums though, the game has a symmetric frustum while the headset’s view frustum is asymmetric vertically and renders more downwards than upwards.
HUD/depth size can be adjusted in the vorpX menu in many games.
Yep I know what you’re saying, but it’s the opposite for me in terms of vertical alignment. The camera is too low! From my perspective, the center of the screen (far back side of the frustum) is above and to the right side.
If I understand you correctly you see a larger border below the screen when you zoom out than above the screen, right? That is precisely what is to be expected and how it is supposed to be due to the different game/headset view frustums.
Yes I would see a larger gap below the screen, but I would see no gap on the right side of the screen.
Vertical alignment doesn’t really matter to me, especially because there’s a camera height adjustment in the settings, but the left <—> right offset is still not centered.
Headset view frustums are also shifted horizontically. Google for “partial overlap vr” if you want to learn how headset rendering works. Again: game and vorpX (headset) camera centers are perfectly aligned. There is no way how that could be any different for you.
Ok this isn’t my image, but it demonstrates the exact problem I’m seeing in Skyrim. Note the UI bar at the top of the page. If I measure the pixels from each tip to the top of the page, it’s much closer to the top of the page on the right side. The left side is something like ~117 pixels, the right side is like ~99 pixels
<——–>
Now, if we look at a regular game screenshot, that UI bar is exactly in the center of the screen, which makes sense as a UI element.
Which camera is identical to the game camera? The right eye camera or the left eye? They both look off-center in the first screenshot, but I’m not sure what you mean about asymmetric rendering of a frustum. Shouldn’t the frustum be centered between the user’s eyes?
I guess this isn’t a great example because the user’s head could be tilted, but it should be the same distance to the edge of vision
Don’t let yourself fool you by any distance of an on-screen element or the rendered image to the screen borders, vignettes or anything else that you may believe look off – they are not. They all are correctly caused by the asymmetric nature of the view frustum and/or the particularities of stereo rendering.
The HUD for example has stereo depth with vorpX, which means it is shifted inwards when you look at the left/right images side by side. That’s how stereo vision works.
Everything is as it should be. You really can trust that.
Ugh, this is driving me crazy man, especially because you’re so determined that it’s correct. UI element that should be in the center, but it’s not. I have to look up and to the right. You say this is how it’s supposed to be, but it’s obviously not correct.
I can zoom out with Shift+Scroll so that bottom corners of the screen touch the circle of my vision with my right eye, but if I just use my left eye, I cannot see the bottom right corner. Obviously not in the center, so stop telling me its right!!!
Lol, I really like this project and the game is BEAUTIFUL, but I can’t use it without adjusting my camera’s left <—> right. Anyways man, thanks for the replies and please let me know if camera left right can be adjusted!!
-James
The HUD elements in Skyrim explitely are not supposed to be centered on the image like when you play mono on your monitor – as already said in my answer above they have stereo depth with vorpX. Creating stereo depth for HUD elements works by shifting the HUD inwards.
That is how it is supposed to be, it’s actually the very basic principle of stereo rendering.
- You must be logged in to reply to this topic.