@Override
    public Vector2f getAxisDeltaSinceLastCall(int controllerIndex, VRInputType forAxis) {
        int index;
        switch (forAxis) {
            case OculusTriggerAxis:
                index = 0;
                break;
            case OculusGripAxis:
                index = 1;
                break;
            case OculusThumbstickAxis:
                index = 2;
                break;
            default:
                return null;
        }

        Vector2f last = lastAxes[controllerIndex][index];
        if (last == null) {
            last = lastAxes[controllerIndex][index] = new Vector2f();
        }

        Vector2f current = getAxis(controllerIndex, forAxis);

        // TODO could this lead to accuracy problems?
        current.subtractLocal(last);
        last.addLocal(current);

        return current;
    }
The object forms of the tracked controllers.
jme3-vr/src/main/java/com/jme3/input/vr/oculus/OculusVRInput.java