External/built-in demo recorder

Hello Community,

pardon if I opened the topic in wrong place. I couldn’t find anything more suitable than general discussion for my question and that is, how hard would it be to create an external or built-in program/function that is capable of creating a so called demo file in an Unreal Engine 3 game, which later on could be replayed by the fellow player?

And I’m talking like a small demo file similar to those seen in Counter Strike series or Call of Duty 4. Is it technical possible in already finished game like Soilder Front 2 (f2p steam game avilable in NA dev. by Dragonfly). In case you still don’t get what the heck am I talking about:

  1. UDK | MovieCapture
  2. UE3:DemoRecSpectator (UDK) - Unreal Wiki


I know it supposly be implemented in UE4 and i think it’s already there… but i don’t know who they name it so i’m not even sure where to search it ;p but 100% sure it’s gonna be implemented if not already, because of UT4 user base demend.

Demos is basing on replication system, instead of replicating state from network stream it replicates states from file stream and you record just by dumping network stream to file. So main requirment is your game work with UE4 replication system, if you use diffrent protocol you will need to write your own replay system