FBX format is good for UE4. Please import 3D data.
Please open default VR projects. If it done,Double click imported FBX data and open.
Please select “Convex~” Next step is setting navmesh bouding box.
Please add from source brower and drag&drop to level. It it possible to change scale if you want.
Please press Keyboard shortcut “P” that is showing navmesh area.
Last, add VRPawn to current level.