Demos were the original reason I started looking at PK, but in fixing demos a lot of other things need to be in place first. But before I explain that let me give an overview of demos as they are now.
Firstly when existing demos are played, they are simply rendering the few entities that you can see and nothing else. There is no game running, the player objects aren
This is slightly annoying, since I had planned to at least write a converter into any new/improved format. The fact a lot of the information I want is not there stored, or cannot be determined from the gameplay, is frustrating.
However, in order to create a new demo format – one where, say, you can run it at any speed, switch POVS, go spec, make movies from it. Effectively what I need is to write the netcode to file, and replay it. Obviously I would not want to store it at rendering fps, or even at netcode fps. To play it back, everything needs to be smooth, being played from any framerate. Of course this is where interpolation comes into play, and why it is so very important. With smooth interpolation I can replay demos and fill in the missing information.
The only thin I have yet to do is to tie up some loose ends of an initial snapshot of the level (item respawn times, etc), although in truth, this can just be captured from the netcode.