Steganography: a tool for community driven development in TerraTech

SteganographyA simple trick that became a powerful community tool

Russ Clarke: Founder, Payload Studios@_higekun @TerraTechGame

Payload Studios

Nearly 1 year old!(TerraTech conceived 1 year earlier)Kickstarter July 2014: target £35k, raised 39Now 7 full time in officeUsing Community Driven Development

TerraTech free demo: http://bit.ly/TerraTechSteamBeta Program (exclusive new content): http://bit.ly/GetTerraTech#madewithunity

© 2014 Terra Tek Studios Ltd. All rights reserved.

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.

Community Driven Development

© 2014 Terra Tek Studios Ltd. All rights reserved.

• 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

Building a Community

© 2014 Terra Tek Studios Ltd. All rights reserved.

• 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

User Generated Content

© 2014 Terra Tek Studios Ltd. All rights reserved.

• “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.

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!)

Steganography

© 2014 Terra Tek Studios Ltd. All rights reserved.

• 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!

Basic Algorithm(from Wikipedia… naturally)

© 2014 Terra Tek Studios Ltd. All rights reserved.

• 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

Key Components

© 2014 Terra Tek Studios Ltd. All rights reserved.

• 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.

http://bit.ly/TerraTechSteganography

© 2014 Terra Tek Studios Ltd. All rights reserved.

http://bit.ly/TerraTechSteganography

© 2014 Terra Tek Studios Ltd. All rights reserved.

http://bit.ly/TerraTechSteganography

© 2014 Terra Tek Studios Ltd. All rights reserved.

http://bit.ly/TerraTechSteganography

© 2014 Terra Tek Studios Ltd. All rights reserved.

http://bit.ly/TerraTechSteganography

Why Is This Good?

© 2014 Terra Tek Studios Ltd. All rights reserved.

• 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

Russ Clarke@_higekun

@TerraTechGameTerraTechGame.com

Twitch.tv/TerraTechGame bit.ly/GetTerraTech