The `SceneSynchronizer` is used to synchronize all the peers using server authoritative networking model. Register an new action. `node` The node that owns the event `action_func` The function that is triggered when the event is executed. `action_encoding_func` The function called to definte the validation encoding. `can_client_trigger` If true this `Action` can be triggered on client. `wait_server_validation` If true the event will be emitted locally only if the server validates it. `server_action_validation_func` The validation function, must return a boolean. Trigger an action. This action can be triggered by the client, only if it was registered with `can_client_trigger = true`. Note: If you pass a recipient the action is notified only to that peer; if you leave it unset the action will be propagated to all the peers. Generally you never specify the `recipients`. In any case, only the server can use this feature. Trigger an action. This action can be triggered by the client, only if it was registered with `can_client_trigger = true`. Note: If you pass a recipient the action is notified only to that peer; if you leave it unset the action will be propagated to all the peers. Generally you never specify the `recipients`. In any case, only the server can use this feature.