I'm going to take a little time to develop 5089, so I wanted to leave a checklist of things we should accomplish for this library. @rickard (or anyone, really) -- feel free to grab one of these and make a pull request:
1) Mouse cursor in VR: Right now, if the mouse cursor is displayed, it draws over the distortion scene. The cursor needs to be replaced automatically by a spatial in the GUI scene. Perhaps VRApplication can set the cursor icon to "null" (so it doesn't draw the default white one) & monitor if the cusor is visible? If it is visible, add the VRGuiNode-attached spatial & set it to the cursor position?
2) VR Input: OpenVR has functions for accessing different input methods. We need to make those available, easily, to our jMonkeyEngine developers.
3) Filter tweaks: in the current demo, I noticed the ambient shader looks different in one eye (at least when hooked up to the Rift). The cartoon lines worked fine, though, and they are part of the same shader... perhaps test other filters, like FXAA etc.
4) More GUI positioning options: right now, it is either stuck to your face or floating freely in space. There should be more auto-positioning options, like ones that let you "look down" to the GUI, but look up away from it (like looking down at a map). In that case, the GUI would be clamped to looking left & right, but not up & down. Another option is to clamp the GUI elements to the observer spatial, and not the position of the headset. This would allow a player to look around the GUI elements, but they'd always be near.