PCSX2 is a PS2 emulator for PC. Most would think that it doesn't or can't support a VR headset, but they would be wrong! Follow these steps, and you'll be up and running in no-time. WARNING: This is most likely going to be very hardware intensive, so a powerful computer is recommended. Speedhacks are a necessity.
I'll be using the Oculus Rift for this guide currently.
Step 1 - 3D Edit
The first step is getting 3D to work in the emulator. This is done using a modified video plugin, called GSDX-3D. Download that here: http://forums.pcsx2.net/Thread-Gsdx-3D-Stereoscopy-Patch
Once you download that, follow the steps on the forum page to get the plugin working. Boot up a game, and viola! 3D! You can change the 3D settings in-game using the * key on your keyboard. For this, choose the Side-By-Side method.
Step 2 - Oculus Rift Edit
Now that we have the 3D, we'll need to get the view to the Rift. The best way to do this now is with a program called Oculus Overlay. It's a program created by Holophone3D that can take a screen region on your computer and apply the correct distortion to the view. The program *technically* is only for the DK1, but there is a workaround to getting it to work with the DK2.
Alternate Methods Edit
Mentioned above is the free, guaranteed working version of getting PCSX2 into the Rift. VorpX DOES hook into PCSX2, but the way it displays doesn't work with GSDX-3D. Don't use VorpX for this.
Step 3 - Configuring GSDX-3D Edit
Now that we have the Rift's display up and running, you'll need to mess around in-game with GSDX-3D's settings. Luckily, the plugin is very versatile and with the right settings can fit the profile of most PS2 games. This is down to mostly personal preference and will probably change with each game.
In the plugin's folder that you downloaded, there should be a readme file. This contains all the commands that will change the 3D config in-game. You'll need to change these around for every game you try. Try your best to get the correct scale for the game, and to where the 3D is the most comfortable for you.
This is what Shadow of the Colossus looks like:
Step 4 - Configuring OpenTrack for headtracking Edit
Headtracking is important for Oculus Rift games, and PCSX2 is no exception. Obviously the camera for different games will work better than others, but use this as a general guide.
If you haven't already, download OpenTrack here: https://github.com/opentrack/opentrack/releases
Now, within OpenTrack, set the tracker to use the Oculus Rift, the protocol to mouse emulation, and the filter to EWMA.
Step 5 - Configuring PCSX2 for headtracking Edit
We'll also need to change a few settings in PCSX2 to get the mouse emulation from OpenTrack to be recognized in game. In PCSX2, go to Config>Controllers>Plugin Settings.
You'll need to enable the Mouse API. Change it to Windows messaging. If another setting works better for you, use it, but this is my recommendation.
Next, open up the Pad 1 tab, and within on the right side, clic
k the button titled "Mouse". Press M. What this does is when in a game in PCSX2, pressing M will enable mouse control to whatever you bound the mouse to, which is what we need to do next.
You'll want to bind the mouse movement to whatever the game uses to control the camera. This is usually the Right Analog Stick directions, so I'll use them here. Click the Up button, then move the mouse up. Repeat this for the other directions with the mouse.
Step 6 - Getting headtracking to work Edit
Load up a game in PCSX2. Now go back to OpenTrack. Go ahead and start it. Now go back to PCSX2, and press M in the window. This should enable headtracking now, so when you look around with the Rift, the camera in the game moves. Something might be wrong, like the camera is too sensitive, or the directions are flipped. Here's how to fix those:
For the camera sensitivity, go back to the Pad 1 controller settings in PCSX2. On the right, you should see a "Configure Binding" menu. If you click on one of the right analog directions, go ahead and rebind the mouse to it. Now, change the sensitivity down to your liking.
For flipped directions, this will need to be changed in OpenTrack. Go to OpenTrack, then on the bottom right click the Options button. Go to the last tab, then invert the directions that are flipped.
And that's it! If you did everything correctly, you should be well on your way to playing PS2 games with your Oculus Rift! Have fun!