Development of Methods and Concepts for the Creation of a Storytelling Based 3D Action Role-Playing Game

This work presents the development of methods and concepts for the creation of a storytelling based 3D Action Role-Playing Game (Action-RPG) named Tib's Quest. Action-RPGs have two particular aspects in which we are interested in this work: in the one hand real-time action and combat system in a 3D-environment, and in the other hand storytelling elements where the player has to ask the other non-player characters for the next quests to fufil. We implemented the 3D-game engine using the DirectX API in C++. We kept the classic top-down view of the early 2D console Action-RPGs, which simplifies the rendering optimizations. However, we still need some classic 3D-engine features like frustum culling, which we implemented by traversing a quadtree structure. To perform collision detection and response, we implemented a version of a swept sphere algorithm. The terrain structure of the game engine involves classic heightmap and lightmap, and is able to represent both indoor and outdoor environments. The lightmap is computed by ray-casting supported by the quadtree structure. We present and implement a game object component system to represent the game objects populating the virtual world. It is used instead of the usual inheritance-based approach. One advantage of the component-based system is to provide a natural data-driven system which we use to compose the game objects from outside the game executable. The game objects are geographically registered on a grid to perform efficient proximity tests such as collisions and interactions. The storytelling relies on the ICML format (Inscape Communication Markup Language) which enables to describe interactive stories and the Narration Controller, an external DLL which is able to read ICML stories and manage the story states. Programming an interface between the Narration Controller and a 3D-game engine as well as illustrating the ICML interactive storytelling capabilities in an Action-RPG are the final achievements of this work. We also provide a level editor