FSCKING LAG

A lightning talk on multiplayer networking that we gave at /dev/world/2015.

Transcript

2. FSCKING LAG
3. Video Games!
4. Multi-player video games!
5. Server
6. Server Client Client Client
7. Server Client Client Client
8. Server Client
9. Server Client “I just killed player 1”
10. Server Client “I just killed player 1” “ok”
11. Server Client “I just killed player 1” “ok” BAD
12. Server Client “I pressed these buttons” “This is where things are”
13. Server Client “I pressed these buttons” “This is where things are” BETTER
14. PROBLEM
15. 1 2 Lag = 1 second Lag = 0.1 seconds
16. 1 2 Shoots! Runs! FROM PLAYER 1’S PERSPECTIVE:
17. Server Player 1 Player 2
18. Server Player 1 Player 2 “I’m shooting!” (1 second ago)
19. Server Player 1 Player 2 “I’m shooting!” (1 second ago) “I’m running around the corner!” (0.1 second ago)
20. Server Player 1 has shot, and Player 2 is around the corner. Player 1’s shot missed.
21. Server Player 1 Player 2 “Player 2 is now around the corner. Player 1 shot, but missed.”
22. Counter-Strike
23. Server Player 1 shot, and at the time, they were aiming at Player 2. Their should would have hit.
24. Server Player 1 Player 2 “Player 1 shot Player 2.”
25. Server Player 1 Player 2 “Player 1 shot Player 2.” “Oh, and Player 2 still ran around the corner. lol.”
26. Server Player 1 Player 2 “Player 1 shot Player 2.” “Oh, and Player 2 still ran around the corner. lol.” wtf
27. Age of Empires
28. 1500 Archers on a 28.8: Network Programming in Age of Empires and Beyond Mark Terrano, Paul Bettner
29. PROBLEM: 1500 archers Each one has a position Each one is moving
30. Each position is about 4 bytes each
31. 4 bytes ✕ 1500 = 6000 bytes
32. 6000 bytes ✕ 30 frames/sec = 175 kB/s
33. SOLUTION:
34. DON’T SYNC STATE
35. SYNC PLAYER INTENT
36. Client Client Client
37. Client Client Client “I told my archers to move.”
38. Client Client Client “I told my archers to move.” “I told a villager to gather wood.”
39. Client Client Client Wait for everyone to finish this frame….
40. Client Client Client Archers are moving, and the villager is gathering wood.
41. NOT PERFECT
42. RUNS AT THE SLOWEST PLAYER
43. DESYNCS
44. @thesecretlab rocketboxgame.tumblr.com