Scenario Playback doesn't restore status of doors, gear

[ssope]

Whenever I play back a recorded file in orbiter, for example the XR2, the playback won't remember that I opened the outer doors of the air lock, and the rest of the playback doesn't progress. Or for instance, the DGIV will lift off correctly, but won't remember that I put the landing gear up, so the landing gear breaks off and the rest of the scenario runs on

 

[Tommy]

Things like landing gear status, nosecone operation, etc, are "animations" as far as Orbiter is concerned. The Orbiter core doesn't record them - since they are vessel dependent.

It is possible, through the Orbiter API, for vessel devs to recored these events, and play them back. The stock DG, for instance, records some of these events.

There are two likely reasons why vessel devs like Dan (DGIV) and Doug (XR-series) don't implement this in their vessels:

1; It requires extra coding, for a feature (flight recording) that wasn't used much in the past. Flight Recording in general is fairly new, and wasn't used much when many of these vessels were first developed.

2; There was some confusion in the way events would be handled. Martin stated fairly early on that event recording would be handled differently in the 2010 releases. Where "animation" events were formerly recorded in the .atc file (along with engine throttle states, annotations, time Acc, etc,) these events have now been separated into a fourth file (formerly there were only .atc, .att and .pos files). I suspect that many devs held off on implementing the coding for these events until the recording format was "cemented". Why spend time developing code to record these events if you would only have to re-do all the code to work with the new format?

The DGIV, for instance, will still work if the viewer inputs the correct key commands (ie, "g" key for gear, "k" key for nosecone, at the appropriate time in the recording (the DGIV doesn't respond to "2D panel inputs" during a playback (MFD's can still be adjusted if using the "glass cockpit" mode), and the annotation's can instruct the viewer when to press what key.

The only real solution is for vessel devs to add the required code to make these "animations" work with the recorder/playback feature. They will likely only make the effort to do so if they know that enough people really want those features - and are confident that the code will work (or can easily be modified to work) in future versions of Orbiter.

Even then, there are limitations to the "record/playback" feature. The most significant (as far as devs are concerned) is that the recorder doesn't have any way to handle vessel creation or deletion during a recording. Any vessel present in the scenario file will persist throughout the recording - and no new vessels will be recorded. This comes into play especially when dealing with UMMU and UCGO. A UMMU, for instance, only exists (as far as the orbiter core is concerned) when it is performing an EVA - UMMU aboard a ship don't exist (as far as the core is concerned) except in the vessel modules memory. The same applies to UCGO - they only "exist" when unloaded. They are spawned when they are jettisoned (or EVA'd) and deleted when they are "loaded" (or enter a vessel). The recorder doesn't handle that.

For instance, if you EVA a UMMU during a recording, that UMMU will never appear during a playback. If a UMMU enters a vessel during a recording, during the playback the UMMU will NOT enter the vessel - and since the UMMU "vessel" isn't recording it's attitude and position any longer it will simply "drift" about for the duration of the flight, based on it's last recorded state.

 

[dbeachy1]

Thanks for the heads-up on this. Regarding the XRs, at least, Tommy is correct that it simply hasn't had much attention. I'll make some notes to add more coverage for ship playback events in the next XR releases. :tiphat:

 

[ssope]

Tommy, thank you for a very in-depth and complete answer. And the XR2 is awesome, that would be great if the recording problems were fixed. Also can't wait for the XR MK2, the interactive virtual cockpit is going to be awesome.

 

[Aeadar]

Regarding gear retract on XR vessels during playback; While using playbacks to review and practice landings in the XR5, I've noticed that if I press 'G' at the beginning of the playback, the gear will lower at the point I lowered it during recording. I don't know if this holds true for retract after takeoff or for nosecone or bay doors but worth a try.


Edit: I checked an XR5 takeoff playback and it worked. Gear retracted as recorded after pressing 'G' at playback start (although I sink into the tarmac as I rotate.) I've also had no trouble with cabin hatch and radiator working as recorded in playback.