Rewind demo playback?

[VegasKill]

Hello,

I'd like to call for your advices:
could a mutator reverse the playback of demos?


With the rypel cam mutator (records cinematic cutscenes from demos) you can change the way a demo is reproduced, so if anyone has an idea of a code snippet to reverse the demo playback, please reply here.

[Wormbo]

You cannot let a demo run backwards. (Demos aren't stored frame-by-frame, but as network traffic.)
If you need it for a video, manually reverse it after capturing the demo in regular playback direction.

[VegasKill]

Thanks for the reply, Wormbo.
The demo is not supposed to play reverse while a video is being recorded. It even doesn't need to 'fluidly' play reverse, but only 'jump' to requested points in time - like 1 minute ago.

This would find it's use in the preparation phase for the recording, when a camera path is built with the rypelcam mutator.
Timing is vital when you work with rypelcam: every 'key point' for the camera stores the time when it was created. This data is saved, the demo is restarted and an autopilot will control the cinematic camera, with the speed based on the demo time.
Any kind of missed action, the need for corrections or also improvements would demand to go back in time, i.e. restart the demo, as for now.


If a demo works like network traffic, maybe there could be some functions from online gaming? like when there is a huge lag or timeout, there can be a 'NetUpdate' and the server receives corrections from clients or send corrects (like when you warp, the server corrected your position).

Sorry if this didn't make any sense, but I'm new to unreal script, and don't know a lot about it, yet. Rypelcm takes movies to a whole new class and there is demand for improvements, therefore I'll try to keep the development going on.

Cheers

[Wormbo]

Not sure about that. I heard they were working on such a feature, but then UT3 didn't ship with demo recording at all. The thing is, a demo's current state, like that of a network game, depends on everything that happened before. There are no complete snapshots, just continuous updates and the client (demo playback) simulates behavior from the values received. Yes, the server provides correcting data once oin a while, but only for individual actors, not for the entire level and definitely not in a synchronous manner.
Jumping back in time essentially involves starting the demo from the beginning and replaying all the network data and simulation logic.

[azurescorch]

pretty sure it can't be done for reasons stated above.
I only know of one game with proper rewind controls etc. Hopefully all future games will have such control over playback.

[VegasKill]

Well, that's a pity, but thanks for the info.