I made a post on /r/oculus, putting it here as well for visibility:
---
Alright, I found a way to get head tracking and stereoscopic 3D working with a DK2 and a AMD r9 290x in DCS World. With some slight additions to a post by Jeesus on the DCS forum which you can find here: http://forums.eagle.ru/showthread.php?t=129728
You will need:
A Oculus Rift DK2 (of course) I'm running SDK 0.4.3
DCS World
Notepad++ or your favorite editor
Opentrack 2.x (I used the latest beta release - 2.3 as of writing) You can find it here: https://github.com/opentrack/opentrack/releases
Setup steps:
0. Turn off your rift.
1. "go to the DCSWorld\config\Monitorsetup folder and open the Stereo.lua in notepad++ and edit the "eyeshift" lines to your needs, this is basicly the IPD in stereo rendering, it is experimental, whatevere fits your eyes the best (on default it is 0.06 which is waaaay too high, the best for me is 0.035)"
2. Startup DCS world and set your graphics preset to low, 1920x1080, and the screen as "stereo". Turn off Rift Auto Detect and Full screen. We also don't want VSYNC, AA turned on etc. I unchecked all the boxes.
3. Exit DCS, turn on your rift and put it in extended mode, make sure it's in portrait/landscape mode and that its working properly.
4. Go to wherever you downloaded Opentrack and unzip/run the application. Set the Tracker to "Oculus Rift -- HMD" and the Protocol to "Freetack 2.0 Enhanced". Click Start. You should now see telemetry from the rift on the screen. Settings Screenshot: http://imgur.com/zbER3aM
5. Start DCS again, go into a fast mission (or other game mode, I've only tested fast mission as of writing) and start it up. Click fly and at this point you should be able to do the mission like you normally would. You can probably get away with not loading into the missing and staying in the briefing room but I just sat on the runway at this point. Just make sure the application launches and is ready to go.
6. Alt-Tab - minimize DCS, and right click->screen resolution and set your rift to as the primary display.
7. DCS should move over to the rift and all you need to do is mouse over to the rift display, click once to set focus on the DCS window and viola! You should have headtracking and input from your joystick(s).
8. Fly your mission and enjoy.
This is "Functional" I was getting about 25-60 fps depending on what was going on. That's all settings on low with an r9 290x, not the best performance. However, I would say it was "tolerable", and your mileage may vary. Please give it a try and let me know if it works for you as it is the only way I know of at the moment to play DCS with a Rift using an AMD graphics card.
