A subtopic of AI which is called "game ai with behavior trees" is covered often in books. A recent example was released one month ago and describes the practical problems of programming a Game AI with the Unreal Engine. Unfurtunately, the books isn't available under a creative commons licence. It seems, that the Open Access movement never took place in the domain of game development. But let us take a look into the content. The general idea is, that Game AI is a topic near Computeranimation, leveldesign and Game engine parametrization. It's a technique to increase the realism of computer games.
The book starts with a chapter about the history of Game AI with many examples from the past. Sections are provided like navigation, environment query, agents and behavior trees. The behavior tree chapter is the largest one and explains in detail how to realize such a system with C++ in the Unreal engine. Many screenshots are used in which it's explained which menu point has to be selected to program a simple AI agent. In the Unreal Wiki, which is available online, the same information are provided, but not in linear fashion but distributed over many categories.
- Francesco Sapio: Hands-On Artificial Intelligence with Unreal Engine: Everything you want to know about Game AI using Blueprints or C++, Packt Publishing Ltd, 2019
- Unreal Wiki, https://wiki.unrealengine.com