- Since my work at the Zuse Institute concerns the simulation of large molecular systems, I was interested in a proper visualization in a stereoscopic manner. Of course, there are several ways to produce stereoscopic pictures. However, in the following, I am going to describe exactly the hardware-driven system that I was able to set up successfully. The strory is about NVIDIA's 3D Vision technology in combination with an Acer 120 Hz LCD monitor and a proper graphics card on an Ubuntu 10.04 amd64 linux system.
Requirements on Hardware and Software
- NVIDIA 3D Vision kit: shutter glasses with an IR-emitter.
- If not ordering from the United States, a connector cable from 3-pin mini-DIN to 2.5 mm stereo needs to be ordered seperately, e.g. for shipping to Europe. Contact NVIDIA's suppport for that or see below, how to connect the pins.
- NVIDIA graphics card of the Quadro FX series (with a G8xGL or higher GPU): I chose the Quadro FX 3800, but necessarily with a 3-pin mini-DIN connector which is required on linux systems!
- A 120 Hz LCD monitor, necessarily with a horizontal refresh rate greater than 130 Hz and a vertical refresh rate with at least 120 Hz. I decided to use the Acer GD245HQ supporting HD resolution.
- A DVI dual link (no single link!) cable for connecting the monitor's DVI port with the Quadro FX card's DVI port. It should come with the monitor.
- A new NVIDIA driver for the graphics card. The current version (195.36.24) from the Ubuntu 10.04 repository is sufficient for our purpose.
- Visualization software with stereoscopic functionality: e.g. VMD, Deep View (Swiss-PdbViewer), amira, and I guess PyMol knows the trick as well.
- Install the "mesa-utils" package which provides a simple test for the stereoscopic functionality.
Installation and Testing
- Actually, the whole task is easily done if one knows what to do.
- First, install or activate the graphics driver of NVIDIA and make it run properly.
- Start "nvidia-settings" and save an X configuration file (xorg.conf), if not already existing in /etc/X11/.
- Back it up like with the following command e.g.
sudo cp /etc/X11/xorg.conf /etc/X11/xorg.confBACK
- Now, you need to modify your xorg.conf by hand or better by using the "nvidia-xconfig" command:
sudo nvidia-xconfig --allow-dfp-stereo
sudo nvidia-xconfig --ubb
sudo nvidia-xconfig --stereo=10
This will add the following lines into the "Screen" Section of your xorg.conf (can also be done by hand):
Option "AllowDFPStereo" "yes"
Option "UBB" "True"
Option "Stereo" "10"
Where "10" stands for the 3D technology provided by NVIDIA's 3D Vision system. See here under Appendix B for additional information on X configuring.
- Add the following option to the "Extensions" section to your xorg.conf if it doesn't already exist:
Option "Composite" "Disable"
- If it is not the case, disable the TwinView functionality in your config file's "Screen" section:
Option "TwinView" "0"
- Now, shut down the pc and connect the emitter via usb to the pc and additionally, via the according cable to the 3-pin mini-DIN connector of your graphics before starting the pc!
- The monitor should already be connected by the dual-link DVI cable.
- Starting the pc under these conditions should let the emitter turn from a red to a weak green light when the login screen of ubuntu appears. If the emitter's light still appears red, something went wrong with your configuration.
- Test your stereo system with the following command in the terminal:
If you see a small window with rotating gears, put on your glasses and turn them on if not already happened. You should see a 3D picture, hopefully.
- Now, you're able to use 3D stereo techniques as provided by e.g. the molecule visualization software VMD: load a molecule file and in the main menu set
- Fortunately and if desired, you can also use TwinView for a second screen. Just set it in the nvidia-settings window after having started your pc. However, if you save this option to your xorg.conf file, the 3D vision system won't work properly after the system's next start unless you disable the option in the config file and restart the machine.
2.5 mm stereo connector to 3-pin mini-DIN
- Assuming that you want to tinker such a cable by yourself, the 2.5 mm stereo plug
---..---| |-------| |--------| |
| | | | | | |
---''---| |-------| |--------| |
a b c
tip ring sleeve
- needs to be connected to the graphics' 3-pin mini-DIN (view from soldering side!)
/ \_/ \
/ 3 \
| 1 o 2 |
| o _ o |
\_ |_| _/
in this way:
1 -> c, 2 -> b, 3 -> a. The upper drawings were taken from here and slightly modified.