Project from Ádám Horváth demonstrates how the Unreal gaming engine can be used for augmented / mixed reality experiences using a dramatic fight scene:
Augmented Reality Plugin for Unreal Engine 4 allows developers to use Unreal Engine 4’s Blueprint visual scripting system to create multi-platform Augmented Reality experiences as seamlessly and as easily as possible. Powered by the OpenSource ARToolkit framework. The world’s most widely used tracking library for augmented reality.
More here and here