Replay demo from a non-interactive camera

[_bryan]

Maybe it's already been suggested, but searching for 'demo' or 'playback' comes back mostly with questions about mod demos. I can understand something like this probably would have no priority or might be more difficult than appears.

Though to name a few posts/projects I've found or been told about to show there's maybe a bit of interest:

* https://github.com/borogk/zdoom-cameraman
* viewtopic.php?f=46&t=64320
* viewtopic.php?f=4&t=25715

The demo playback is a non-interactive repeat of all the inputs during a session. It is fixed to the first person camera, though with the ability to spy through other cameras. As it stands now this isn't supported because the playback is the game. The playsim doesn't support this.

It's quite difficult to make a good variety of clips when you're locked into only the first person perspective. To do something like this properly requires hacking one of the players to be a ghost that fly's around the scene capturing footage, setting up a map specifically for the scene, and then coordinating what could be a day of shooting over, and over, and over. This might be inevitable for certain scenes, but for complex segments that aren't easily achieved it's not trivial either acting it out over and over or even asking volunteers to please endure. When I'm on my own using what's currently available that's not even possible when I have to aim and dodge via a disconnected camera.

I'm not suggesting interfering or modifying the current playdemo implementation, but is there some possibility/want in the future of there being engine side support for viewing demo's from cameras other than the players (or rather non-interactive cameras)? Outside of my personal desire I could imagine this would be extremely helpful to others for their own media creation needs, be it trailers or 'machinima' style clips, or lowering the barrier for others without modding/mapping experience.

[Graf Zahl]

I can understand something like this probably would have no priority

Correct. If someone volunteers it may happen, but don't hold your breath...

[Gez]

At some point there was an attempt at allowing several level instances to run at once, which would have allowed things such as not everyone having to be in the same level during a multiplayer game; but it wasn't successful.

I figure this would be a prerequisite to allowing to play a demo on a screen in a level, as you'd be playing the demo and the level in parallel.

[Rachael]

That doesn't seem to be what this person is asking.

prBoom has this feature - when playing back a demo you can press a key to "disconnect" from the recording player during playback and freely roam the level while the demo is going.

I think this is already doable with a little ZScript hackery/magic (heh) - but play/ui scoping might interfere with this working properly. (Though there's ways around that nowadays ... you can trade info between scopes using unsync'd cvars from cvarinfo, for example - as long as you do not modify any demo-sync'd objects this should not cause desyncs - and if you do spawn any cameras, make sure they're non-interactive with the world)

[Nash]

At some point there was an attempt at allowing several level instances to run at once, which would have allowed things such as not everyone having to be in the same level during a multiplayer game; but it wasn't successful.

Any chance for the multi-level system to make a comeback, Graf? :(

Even if it won't allow multi-level players, it's fine by me. I just want to use it for shared skyboxes between levels...