Thorsten wrote on Sat Jan 28, 2012 9:41 am:
I have a hard time imagining why this should be important enough to spend even 20 minutes on coding it though.
I see, I think the problem is that replay cannot work for certain sub systems if these systems don't have a concept of replaying a recorded flight. So, basically subsystems not honoring other subsystems, make it impossible for them to work fully/properly. It would be impossible for replay to handle the needs of all other subsystems. So it's all about clearly defining responsibilities. And I actually agree here: At the moment, this isn't critical or crucial at all: The lack of replay support is not a major showstopper currently. However, at some point this may introduce additional breakage because other features are getting built on top of systems that are not fully supported.
For local weather it might actually be a worthwhile feature for different reasons: more and more improving the architecture. There are a number of related features that would be directly related to being able to interrupt and resume the system gracefully.
For example: At the moment, it isn't possible to save and load flights in FlightGear, but ThorstenB mentioned already that he's planning to support this for recorded flights eventually. Now imagine you were demonstrating FlightGear to new users or using FlightGear in an instruction-related scenario. You'd probably want to be able to also record and replay environmental aspects of the simulation, such as weather/clouds? But also AI traffic?
But there are other features that are not yet supported in certain use cases, i.e. connecting multiple FG instances in a master/slave fashion, AI, multiplayer. Basically, this is all about synchronizing state across several clients/instances. Some parts of FG try to work around these issues by using a corresponding RNG with a shared seed.
But at some point, this will inevitably require a capability to serialize some active subsystem specific state in order to de-serialize it somewhere else. Regardless of it being in a multiplayer setup or master/slave setup, or just the plain capability to save and continue a flight at a later time.