I was able to get WOFF UE to work with VIVE. Head tracking with the headset works fine. Only problem was that when I used "geometry" setting in Vorpx, there would be a lot of screen flicker even after disabling shadows, so I had to choose "Z-Normal".
Used Opentrack with Vorpx. Simple setup. Didn't need to use any virtual desktop either, Vorpx just hooked into cfs3.exe when it was launching.
I've got Vive recently and heard about VorpX but it is quite costly and I wasn't sure if it will work with WOFF so I didn't try it. Since I have the headset now I might tackle proper VR support at some point.
That's correct, if you mean by that a perception of depth. Now, it's like wearing trackir with my head inside a spherical monitor. I can physically turn my head and look behind me to see the tail of my plane, or directly down at the floor to see a compass.
I set up pitch, roll, yaw, y and z axis to a 1:1 ratio with my head movement (i.e. turning my head 90 degrees will turn it 90 degrees inside WOFF). I only needed to adjust x axis because side-to-side movement wasn't working right.