SceneKit Server Client Render Script

I am working on a server and client based network game in Scene Kit. Since the server and client have duplicate copies, I am currently loading the same scenes into SCNScene on the client side and SCNScene on the server. However, I have yet to find a way to actually run the physics simulation on the server copy of SCNScene without rendering in SCNView. How can I configure (a custom SCNRenderer?) That drives the simulation without actually rasterizing any frames?