The document discusses how Payload Studios, the developer of the game TerraTech, uses steganography to allow players to share vehicle designs they create in the game by encoding the design data into screenshots of the vehicles and sharing the images on Twitter. This provides a way for players to asynchronously interact and share their creations without requiring complex multiplayer networking code. The developer argues this approach builds the game's community and promotes viral marketing of the game through shared player content.

1. Steganography
A simple trick that
became a powerful
community tool
Russ Clarke: Founder, Payload Studios
@_higekun @TerraTechGame

2. Payload Studios
Nearly 1 year old!
(TerraTech conceived 1 year earlier)
Kickstarter July 2014: target £35k, raised 39
Now 7 full time in office
Using Community Driven Development
TerraTech free demo: http://bit.ly/TerraTechSteam
Beta Program (exclusive new content): http://bit.ly/GetTerraTech
#madewithunity
© 2014 Terra Tek Studios Ltd. All rights reserved.

3. Community Driven Development
• Early Access in ~2 months, Beta available now
• New release every 2 weeks at least
• twitch.tv/terratechgame …every weekday, 5pm
• Probably >10% dev time consumed by community-oriented
activity
Why?
• Game development is expensive
• Marketing & UA are expensive
• Up-front investment is high risk
• What if you’re wrong?
…don’t know until it’s too late
© 2014 Terra Tek Studios Ltd. All rights reserved.

4. Community Driven Development
• Minimum investment before validation of concept
• Get to market really fast, reduce risk of being
gazumped
• Evolve design with continuous feedback from players:
way better than any market analysis
• Build community as you go, instead of spending $$$ on
launch-time ads and UA
• Early revenue delays the financial crunch point
© 2014 Terra Tek Studios Ltd. All rights reserved.

5. Building a Community
• TT is the right kind of concept
• Expressive, emergent, sharable, performable
• But community depends on player interaction
• Dev => players interaction is just an audience
• Multiplayer is a great way to do it!
• …but network code is hard
• Key aim is to provide a shared experience
• Showing off
• Exposure to others’ creativity
• Competition
© 2014 Terra Tek Studios Ltd. All rights reserved.

6. User Generated Content
• “Share my vehicle design”
• Send a digital representation of vehicle build
• Need a backend & API
• Need search, annotation
• Must be reliable, scalable
• Must be smooth, intuitive
• Could be complicated!
…then, a brainwave
© 2014 Terra Tek Studios Ltd. All rights reserved.

7. What if we could piggyback the whole thing on an existing service?
…like Twitter
What if we could attach a data payload, via content that’s routinely shared?
…like pictures (perhaps even pictures of TerraTech vehicles!)
© 2014 Terra Tek Studios Ltd. All rights reserved.

8. Steganography
• Greek “hidden writing”
• ~2500 year recorded history
…mainly for secrecy
• Digital imaging makes it easy!
Here are 2 versions of the most awesome
Stegosaurus picture on the whole internets…
One of them contains a transcript of the
opening scene from Jurassic Park. Can you tell
which? No you can’t!
© 2014 Terra Tek Studios Ltd. All rights reserved.

9. Basic Algorithm
(from Wikipedia… naturally)
• Store 1 bit in LSB of each pixel colour value
• 3 bits per pixel
• 640x400 = 768,000 bits (96,000 bytes)
• Vehicle design storage (per block):
• Position: 3 floats = 12 bytes
• Orientation (orthographic): 1 int = 4 bytes
• Block name: string, typically <24bytes
• 40b /block, so 640x400 => 2400 blocks
• Easily reduce to 3b + 1b + 2b per block, 16k blocks total
• Also can increase image size
Conclusion: more than enough space to store the biggest
design we will ever have
© 2014 Terra Tek Studios Ltd. All rights reserved.

10. Key Components
• Small representation of stored vehicle design
• Capture a screenshot of current vehicle
• Encode design into pixels, store as PNG
• Send in a tweet
Also need:
• Search tweets and load images
• Decode from pixels
• Authentication
The following code focuses on the encode & decode part, as the rest is
easy with built-in Unity & .NET APIs, plus plugins on the Asset Store
© 2014 Terra Tek Studios Ltd. All rights reserved.

11. http://bit.ly/TerraTechSteganography
© 2014 Terra Tek Studios Ltd. All rights reserved.

12. http://bit.ly/TerraTechSteganography
© 2014 Terra Tek Studios Ltd. All rights reserved.

13. http://bit.ly/TerraTechSteganography
© 2014 Terra Tek Studios Ltd. All rights reserved.

14. http://bit.ly/TerraTechSteganography
© 2014 Terra Tek Studios Ltd. All rights reserved.

15. http://bit.ly/TerraTechSteganography
© 2014 Terra Tek Studios Ltd. All rights reserved.

16. Why Is This Good?
• Players can show off
• Each shared design is a little advert for the game
• Players engage with devs (combines well with twitch)
• Effectively provides asynchronous multiplayer, without
needing network tech
• A shared, community experience
• Building new game modes on the system
…Sumo Showdown
…planned new ‘invasion’ mechanic for player-created designs
© 2014 Terra Tek Studios Ltd. All rights reserved.

17. Russ Clarke
@_higekun
@TerraTechGame
TerraTechGame.com
Twitch.tv/TerraTechGame
 bit.ly/GetTerraTech