Our presentation about Outburst 3D that was our entry for Node Knockout 2011.

1. Outburst 3D
Node Knockout 2011

2. The team
Ari Þór Arnbjörnsson
Flash Developer at Rovio
Eiríkur Heiðar Nilsson
Web Developer at Gagnavarslan
Sveinn Björnsson
Student at Margmiðlunarskólinn
Ægir Þorsteinsson
Web Developer at Landsbankinn

3. Our mission
Real time multiplayer game
3D in the browser
Share code between server and client
Have fun!

4. DEMO

5. WebGL
HTML 5 Canvas element
OpenGL ES 2.0
Shaders
No support in IE

6. THREE.JS
https://github.com/mrdoob/three.js/

7. Models
Maya OBJ JSON
JSON

9. Multiplayer
NodeJS Server - Websocket

10. Best Practices …in 48
hours
Authorative Server
Client shares server code to predict
movement
Lag compensation on server
Compression

11. The packets
Input state – 25
p/sec
Client Server
World state – 25
p/sec
Inputs and gameplay are evaluated 50 times per second

12. Input packet

13. World packet

14. Shared code
Server (NodeJS) and client (browser) run
Javascript
… or rather CoffeeScript

15. Player state
Shared code
Input state
New player
state

16. Lag compensation

17. Packet sizes
For a single player:
Input: 137 bytes
World: 2093 bytes
25 times per second is ~50 kibi/sec

18. Simple delta compression

19. Compression results
World: 2093 => 691 bytes
33% of original size
Input: 137 => 35 bytes
26% of original size
Bandwidth: ~50 => ~20 kibi/sec

20. Future optimizations
Round floating point numbers
Delta optimize the derivative of some
fields
Binary JSON (when browsers add
support)

21. Conclusion
Web Standards are awesome
CoffeeScript on server and client is awesome
Sheep are awesome
V8 is awesome
Real time multiplayer is hard
48 hours go by FAAAST…