private void rotateScreenTo(Quaternion dir, float tpf) {
        dir.getRotationColumn(2, look).negateLocal();
        dir.getRotationColumn(0, left).negateLocal();
        orient.fromAxes(left, dir.getRotationColumn(1, up), look);
        Quaternion rot = tempq.fromRotationMatrix(orient);
        if( posMode == VRGUIPositioningMode.AUTO_CAM_ALL_SKIP_PITCH ){
            VRUtil.stripToYaw(rot);
        }

        if( guiPositioningElastic > 0f && posMode != VRGUIPositioningMode.MANUAL ) {
            // mix pos & dir with current pos & dir
            EoldDir.nlerp(rot, tpf * guiPositioningElastic);
            guiQuadNode.setLocalRotation(EoldDir);
        } else {
            guiQuadNode.setLocalRotation(rot);
        }
    }
Rotate the GUI to the given direction.
@param dir the direction to rotate to.
@param tpf the time per frame.
jme3-vr/src/main/java/com/jme3/util/VRGuiManager.java