To make a KillCam is simply record everything what is happening on the server. Save it for 10-15 seconds. If the player dies play it back to the client.
Also the recording should be server side, to avoid unnecessary network packets.
Since the 4.6 version you have:
But i have no idea if they can be used for this purpose.
If not, then the code should look something like this:
TArray<FFrame> Frames;
void Tick()
{
FFRame Frame; //Frame is a snapshot of player positions / movements
// Fill Frame with player position
Frame.Time = CurrentTime+15; // Set the expiration for 15 seconds.
Frames.Add(Frame);
if(Frames[0].Time < CurrentTime) // Check if our first frame is old enough
{
Frames.RemoveAt(0); // delete the old frame
}
}
It will eat out some memory but you can skip some frames if you need. But this is how it should be recorded. Then to play it back just send the frames to the client one by one.