Does anyone know how demo files in Quake3 work? How they are written? What kind of information is stored in them? Etc? They are so small in file size, it''s mind boggling. I mean, a 10 minute demo is only about 1.22 mb''s in size! But there''s so much information to be held, so much movement, etc? So what is actually stored in the demo files? I don''t think it''s really just a "static" movie, like just thousands of frames of captured screenshots like an AVI file would be...because then it would be incredibly huge in filesize. So... Please explain!

Most likely, all it stores are messages that are recorded. Moveing messages and state changes are stored and they''re played out again as if someone''s playing it.

It''s like Flash, you store the instructions only, allowing such small files. The only thing that takes up space is the graphics, but animation is just a set of instructions.

Stores all the server var
so far you could code a camera mover that allows you to make movie like videos from the outside
There are already some out

Quake demos simply store the network packets. To replay a demo, the network packets are taken from the file instead of from the network adaptor.

well whats inside these "network packets"

In general, game replays are stored in two different ways. One is to save all inputs/time of input and run the game on those inputs, or you can save the orientation and position at each frame (or every few frames and interpolate). Orientations can be compactly saved as quaternions. They are not saved as images.


Mike