Stuttering head tracking in Skyrim

[TiLT]

So I tried running Skyrim with the DK2 and the new version of vorpX yesterday, and I had mixed success. For the record, without the Rift I can run the game at a constant 60 fps with all graphics settings at max and vsync enabled, and no stuttering. When I use vorpX, the game becomes a stuttering mess even at the lowest graphics settings possible.

This seems related to the head tracking, which jumps all over the place. If I look down, the view will jerk around a little and then jump as far down as your view can go. It’s the same thing if I look up, only I’m suddenly looking at the sky. Turning in any direction or moving at all makes the view skip and jump, sometimes a lot, sometimes a little. There seems to be no rhyme or reason to it. Even trying to stay still, the camera will make small jumps and stutters.

Apart from the typical DK2 judder that appears in some Rift demos, head tracking works perfectly for me in everything but Skyrim right now.

What’s going on here? What can I do to fix this problem? My specs are below:

Intel i7-3820 CPU @ 3.60 GHz (8 CPUs)
32 GB RAM
Geforce GTX 780 w/ 3 GB RAM
Windows 8.1

[TiLT]

Well, this seems to have fixed itself somehow. Perhaps the system just needed another reboot.

Now I’ve got more common issues, like an unusually low framerate and head tracking that only seems to track forward and backwards movement, and not much else.

[Ralf]

The framerate is roughly half of what you get without Stereo3 D. Not much vorpX can do about that since everything has to be rendered twice. You probably will have to lower settings to get a good framerate outside.

You can however switch to vorpX’s second 3D-mode, called Z-Buffer 3D. This way the game will run almost as fast as without 3D, but the 3D effect is not as natural. Also there is no positional tracking in Z-Buffer 3D.

[TiLT]

What you’re saying there isn’t exactly true. You may be rendering everything twice, but you’re also rendering it at half the regular resolution per image. Apart from the transformations which will have to be handled separately for each viewport, the pixel count remains the same. For a game like Skyrim, where pixel shaders probably count for the majority of the time spent in the Draw routines, the difference in speed just by adding another viewport shouldn’t be that significant.

I have to assume then that Geometry mode is an inherent drain on the whole thing.

[Ralf]

Hi Tilt,

Believe me, it’s true, I wrote the thing. ;) The pixel count is the thing that affects performance the least. In a stereo driver (referring to Geometry 3D here) additionally to having two draw geometry twice, you can’t apply many optimizations that are thinkable for a native app, since you have to deal with the rendering how it is done by the game, without many ways to influence it.

The performance hit when doing this is largely the same with any stereo driver, being it for the Rift or not.

[jzer0]

Hi,

First just would like to thank Ralf and his efforts, OVR should be kissing your ass for expanding their product’s software library to such a degree.

Now that I’ve kissed a little ass, would ask if there might be a solution to my skyrim problem with head tracking and geometry mode. Only in geometry mode I get this flickering on all of the ground and wall textures whenever there is movement. I have tried all of the following:

– graphics drivers fully updated
– rift extended mode, set to display only on this screen
– various skyrim.ini configurations (deferredShadows, turn off shadows completely, etc)
– happens on a clean skyrim install as well as when modded

I also had this behavior when using Geometry mode with the old vorpx versions and skyrim on DK1. Setting to Adaptive or other modes gets rid of this completely. Unfortunately this also does not allow for the good positional tracking, 3d is not as good. Everything else is running great, good framerate, just can’t resolve this geo mode flickering, last hurdle to full playability.

my rig:
core i7 4960 3.6ghz oc to 4ghz
32gb trident ram oc to 1.4ghz
asus nvidia gtx titan

side question: what determines which 3d modes are made available? is this hardcoded in the vorpx application somewhere or determined based on the target application’s directx implementation?

[Ralf]

Thanks for the ass kissing. ;)

There was one report earlier that sounded quite similar to what you are experiencing. Turned out the the issue was caused by forcing Ambient Occlusion through the nVidia driver, which doesn’t work in conjunction with vorpX in Geometry 3D mode. So that might be something worth to check.

Regarding 3D modes: This has to be done game by game and is a fairly complex process. Technically it’s not hardcoded in the sorce code, but it’s not something that can be done by a user. So in a way you could indeed call it hardcoded.

[jzer0]

HAA HAAAAA!!! RALF YOU GLORIOUS BASTARD!!!!!! Ambient Occlusion was it!!!! Thanks so much, works like a dream now. You’ve made me the happiest boy in all of skyrim.

[spacecadet102]

Ralf wrote:

Thanks for the ass kissing. 😉

There was one report earlier that sounded quite similar to what you are experiencing. Turned out the the issue was caused by forcing Ambient Occlusion through the nVidia driver, which doesn’t work in conjunction with vorpX in Geometry 3D mode. So that might be something worth to check.

Regarding 3D modes: This has to be done game by game and is a fairly complex process. Technically it’s not hardcoded in the sorce code, but it’s not something that can be done by a user. So in a way you could indeed call it hardcoded.

Ralph you son of a gun. This helped me too. lol

[Author]

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