The smooth weather transition API from EF will be free for Sky Force owners, there will be no more abrupt weather transitions with the SF weather engine. This will be called the Weather Force API, included with Creative Update 1.
There are no textures or cloud models included in Environment Force. For cloud and sky sync, Sky Force is necessary, however we will be opening the SDK up to other developers in the near future. Environment Force opens up new roads for Sky Force tech. Watch for free updates later in our Creative Update packages for Sky Force.