I've started using Unity again for some 3D development with Google Cardboard and have been using the new Unity 4.6 UI (which I think is great by the way). Specifically, in order to get UIs rendered for the user in the 3D environment, I needed to place text on a canvas set to
World Space (parenting the canvas to the camera, so that it tracks with the user's head motion). This places the UI in a physical space, which works well for the 3D view but doesn't work well for a HUD where you need it to always be displayed over everything.
After some searching around and not finding a fix, I ended up modifying the default Unity UI shader to ignore z-testing; I've shared it here in case someone else runs into the same issue!Read More