Game Design From Concepts To Implementation

Transcription

1 Game Design From Concepts To Implementation Overview of a Game Engine

2 What is a Game Engine? (Really) Technical description of game: A Soft real-time interactive agent-based computer simulation A game engine is a software made to implement such a system

3 What is a Game Engine? Real-time Interactive Must respond to player input in real time Agent-based Independent entities (agents) live and interact within the engine Simulation It is capable to describe a model representation of a virtual world It is a MATHEMATICAL description

4 A Generic Scheme

5 Let s make it (much) simpler THIS IS MY HUGE BLACK BOX

6 A Black Box for Rules and Assets A Game engine is a container for RULES You explain how the world is evolving, you do not write how to make it evolve The black box will follow your rules and apply them on the asset your provide At every step, the rules will create a new set of assets, making your world magically evolving

7 The Dawn of Game Engines dates back to 1984 with DOOM Strict separation between core software components Strict separation between software and data assets Strong code reusability enforced during development Yet.. The word engine was not there

8 Later on in 90-something Other games have been designed with modding and code reuse as keywords Scripting language (such as quake C) started to be part of the distribution The game engine was now a standalone product (and a profitable one!)

9 Game Engines are Strictly Data-driven A data-driven architecture is what differentiate a game engine from a piece of software that is a game but not an engine When a game contains hard-coded logic or employs special-case code to manipulate specific game objects, it becomes difficult or even impossible to reuse that software to make a different game

10 Game Engines are Specialized The more generic an engine is the less optimized for a certain platform/genre it will be There are specialized engine for certain kind of games USE THE RIGHT ENGINE FOR THE RIGHT GAME

11 Game Engines Survey Quake family FPS Unreal Engine Whatever First or Third person game Very good for prototyping Half Life Source Competitor of Unreal Windows XNA Easy to use (never underestimate this) YouTube (sharing) friendly Heavily PC/XBOX oriented and about to disappear

12 Game Engines Survey In-house engines Sometimes so secret we do not even know the names Open source engines OGRE 3D Easy to use, but NOT a full engine Panda3D Script based, good for prototyping Yake Built on top of OGRE, more fully functional Crystal space Torque Irrlicht

13 Runtime and Tools A game engine is made of two parts: Tools To compile software to work within the game engine To help you describe rules To manage assets To create content Runtime A library/middleware/sandbox/virtual machine This will run your rules on your assets MUST be distributed with the game

14 Let s Break it Down Game-specific subsystem Game virtual machine Interaction Output Network Debugging Gameplay Resource manager Core system Data structures Platform independence layer Graphics Physics Animation A.I. Data structures Third party SDKs and middlewares Graphics Physics Animation A.I. Operating system Device drivers Hardware

15 Game-Specific Subsystem Is where the game designer lives Game-Specific subsystem Weapons Vehicles Power-ups Puzzles Game-specific rendering Game cameras Quests Terrain Water space Player mechanics Collisions Movement Camera Fixed Following Scripted Artificial Intelligence Decisions Perception Path finding