In this presentation, Epic's Paulo Souza uses Unreal Engine's built-in AI features to build smart enemy behaviors for a game with stealth-like mechanics.

By relying on the Gameplay Framework in Unreal, we're able to quickly create convincing AI using Behavior Trees. Behavior Trees are great for creating complex AI that can be presented in a way that is easy to understand and to debug. We also make our AI react to sight and hearing senses using the AI Perception System, but also adapt our Behavior Tree decision tree as well.

In the end, we use the Environment Query System to allow our AI to be aware of the world geometry before deciding the next move, making it look way smarter than it actually is.

Download Unreal Engine for free at http://www.unrealengine.com