Comments on: Vuzix VR920 with Linux and active 3D stereo

By: VRTrack 1.0 – headtracking driver for the vr920 HMD | MyGNU.de

VRTrack 1.0 – headtracking driver for the vr920 HMD | MyGNU.de — Wed, 28 Sep 2011 10:16:50 +0000

[...] As I promised in New version of the vr920 headtracking driver coming soon here is the new version of my headtracking driver for the Vuzix VR920 iwear for Linux. It calculates yaw, pitch and roll from the accelerometer and magnetometer data (The device has got three of each). This makes a 3DOF tracking possible and allows you to look around in a 3D Scene. In example you can use the driver with my stereoscopic image viewer SIV. The driver averages the sensor readings with an improved algorithm, which gives a far smoother experience than with the initial driver version. The driver package consists of a daemon which can be run in the background and for convenience a basic control application that enables one to easily tweak the various driver settings and to callibrate the device. For general Information on how to use the device with Linux see: Vuzix VR920 with Linux and active 3D stereo. [...]

By: SIV 1.1 released | MyGNU.de

SIV 1.1 released | MyGNU.de — Fri, 24 Dec 2010 01:34:54 +0000

[...] In this case try anaglyphic mode or the apropiate 3D mode for your hardware (see the –stereo option). For instructions on how to get the xserver to work in stereoscopic mode see: Vuzix VR920 with Linux and active 3D stereo [...]

By: mithrandir

mithrandir — Thu, 16 Dec 2010 06:56:06 +0000

With nvidia-drivers-260.19.29 the stereo option 10 seems not to work anymore without the nvision hardware and DDC stereo, at least it does not with my Quadro FX 350M. For me it still works with stereo option 1, but users of newer hardware seem to be out of luck. It is really bad how nvidia disables the use of stereo display hardware in their driver with post G80 chips. At least with Quadro FX hardware one could expect all kind of stereo display hardware to work! At least for me this was the reason to use Quadro FX hardware exclusively. Nvidia, you are going to loose another customer.

By: mithrandir

mithrandir — Fri, 22 Oct 2010 16:44:37 +0000

Using this setup I also use the notebook display. This makes things easier when demonstrating applications using headtracking. When one is trying the application with the glasses others can see the same output on the notebook display.

I tried the solution you mentioned. Compiling the demo code from the site this results in synchronization problems. It gives two different outputs, but they are being displayed more or less randomly on the left and the right display. Did you also have this problem?

By: Jonatan

Jonatan — Fri, 15 Oct 2010 12:41:20 +0000

Thanks for the idea, but even with the two settings it didn’t work. The x11 output is still the same.
I don’t really understand the setup of your last post. Do you still have a normal monitor next to your glasses? or not?
However, now I’ve got a quick ‘n dirty solution that is working for my purposes. I’ve used the usb code from
http://www.pabr.org/wxhmd/doc/wxhmd.en.html
to give swapbuffer signals.

By: mithrandir

mithrandir — Fri, 08 Oct 2010 07:48:53 +0000

Perhaps this is also of some help. Here is my xorg.conf with stereo and twinview clone mode for 800×600. It works for a quadro fx 350M.

Section “ServerLayout”
Identifier “Layout0″
Screen 0 “Screen0″ 0 0
InputDevice “Keyboard0″ “CoreKeyboard”
InputDevice “Mouse0″ “SendCoreEvents”
InputDevice “Synaptics” “CorePointer”

Option “Xinerama” “0″
EndSection

Section “Files”
EndSection

Section “InputDevice”
Identifier “Keyboard0″
Driver “kbd”
Option “XkbLayout” “de”
Option “XkbVariant” “nodeadkeys”
#
EndSection

Section “InputDevice”
Identifier “Mouse0″
Driver “mouse”
Option “Protocol” “IMPS/2″
Option “Device” “/dev/input/mice”
Option “ZAxisMapping” “4 5″
Option “Emulate3Buttons” “yes”
EndSection

Section “InputDevice”
Identifier “Synaptics”
Driver “synaptics”
Option “Device” “/dev/input/mice”
Option “Protocol” “auto-dev”
Option “Emulate3Buttons” “yes”
Option “LeftEdge” “120″
Option “RightEdge” “830″
Option “TopEdge” “120″
Option “BottomEdge” “650″
Option “FingerLow” “14″
Option “FingerHigh” “15″
Option “MaxTapMove” “110″
Option “VertScrollDelta” “20″
Option “HorizScrollDelta” “20″
Option “MinSpeed” “0.3″
Option “MaxSpeed” “0.75″
EndSection

Section “InputDevice”

# generated from default
Identifier “Keyboard0″
Driver “kbd”
EndSection

Section “Monitor”

# HorizSync source: edid, VertRefresh source: edid
Identifier “Monitor0″
VendorName “Unknown”
ModelName “IWR iWear VR920″
HorizSync 31.0 – 64.0
VertRefresh 60.0
Option “DPMS”
EndSection

Section “Device”
Identifier “Device0″
Driver “nvidia”
VendorName “NVIDIA Corporation”
BoardName “Quadro FX 350M”
EndSection

Section “Screen”
Identifier “Screen0″
Device “Device0″
Monitor “Monitor0″
DefaultDepth 16
Option “Stereo” “10″
Option “TwinView” “1″
Option “TwinViewXineramaInfoOrder” “CRT-0″
Option “metamodes” “CRT: 800×600 +0+0, DFP: 800×600 +0+0″
SubSection “Display”
Depth 16
EndSubSection
EndSection

Section “Extensions”
Option “Composite” “Disable”
EndSection

By: mithrandir

mithrandir — Thu, 07 Oct 2010 12:08:52 +0000

For me it was sufficient to add the line: Option “ModeValidation” “CRT-0:NoEdidModes”
to the device section of my xorg.conf. Afterwards the vr920 also worked in 640×480. Does this work for you, does stereo work afterwards?

By: mithrandir

mithrandir — Thu, 07 Oct 2010 11:33:03 +0000

You may try out
Option “ModeValidation” “DFP-1: NoMaxPClkCheck, NoPredefinedModes, NoVertRefreshCheck, NoHorizSyncCheck, NoMaxSizeCheck, NoEdidMaxPClkCheck, AllowNon60HzDFPModes”

or similar (depends on your ConnectedMonitor names) in your xorg.conf device section. The interesting option should be AllowNon60HzDFPModes, since 63.2 Hz is the vertical refresh your xorg tries to use. Maybe the vr920 is capable of displaying 63.2 Hz.

Also try out the 800×600 Mode, this is the one I tried. With the 640×480 Mode I currently only get a blue screen. I´ll try to get this to work.

By: Jonatan

Jonatan — Thu, 07 Oct 2010 09:42:11 +0000

Thanks for the idea. However, it now gives a different problem. It attempts to read the EDID info, which is apparently wrong. I’ve tried adding “Option” “UseEDID” “False”, but that didn’t make any difference.
See the xorg log below.
I’ve also posted my question on ubuntuforums:
http://ubuntuforums.org/showthread.php?p=9934622#post9934622

(WW) Oct 07 11:24:34 NVIDIA(1): Unable to find any NVIDIA 3D Vision Stereo mode timings for
(WW) Oct 07 11:24:34 NVIDIA(1): use with the EDID of IWR iWear VR920 (CRT-0); NVIDIA 3D
(WW) Oct 07 11:24:34 NVIDIA(1): Vision Stereo may not function properly. This might happen
(WW) Oct 07 11:24:34 NVIDIA(1): if no EDID is available for IWR iWear VR920 (CRT-0), or if
(WW) Oct 07 11:24:34 NVIDIA(1): the NVIDIA 3D Vision Stereo mode timings were invalidated,
(WW) Oct 07 11:24:34 NVIDIA(1): e.g., if a display port connection lacks adequate
(WW) Oct 07 11:24:34 NVIDIA(1): bandwidth.
(WW) Oct 07 11:24:34 NVIDIA(1): The EDID for IWR iWear VR920 (CRT-0) contradicts itself: mode
(WW) Oct 07 11:24:34 NVIDIA(1): “640×480″ is specified in the EDID; however, the EDID’s
(WW) Oct 07 11:24:34 NVIDIA(1): valid VertRefresh range (60.000 Hz) would exclude this
(WW) Oct 07 11:24:34 NVIDIA(1): mode’s VertRefresh (63.2 Hz); ignoring VertRefresh check
(WW) Oct 07 11:24:34 NVIDIA(1): for mode “640×480″.

By: mithrandir

mithrandir — Tue, 28 Sep 2010 12:36:53 +0000

Hi Jonatan,

this option is for cards (and glasses) with the special vesa stereo connector. I use it with my old Relevator glasses and a Quadro FX 3400. You can see the connector here: http://www.stereo3d.com/vesa3.htm The signal is triggered automatically on pageflip if the card is in quad buffered stereo mode. So if your laptop does not have this connector, stereomode 3 is no solution for you.

Are you trying to get the vr920 to work? I just tried stereomode 10 (the one for nvidia vision displays) on my Quadro FX 350M and wondered. It works! So stereomode 10 could be a solution for you. Please let me know if this works also with your newer GPU.

Jürgen