Game Engine for Serious Games

An Overview by

Flt Lt Kashif Shamaun

What are Serious Games

• A game designed for a primary purpose otherthan pure entertainment. The word “serious“is generally appended to refer products usedby industries like defense, education,scientific exploration, health care, emergencymanagement, city planning, engineering,religion, and politics.

Examples

Basic Components of Game Visuals

• Game Engine aka Rendering Engine

• Image Generator the hardware

• Visual Database

GAME ENGINE

Component I

Game Engine

• Controls the presentation of game world– Geometry and Texture

– 3D Sound

– Simulation (i.e. Physics)

– AI

– Network Traffic

– Environment

– Multiplayer

What is there in Game World

Environment Physics Model Physics

3D Models

3D Sound

Terrain

Texture

AIObject Physics

Geometry & Textures

• Terrain

• 3D Models

Satellite Images + DEM = Terrain

Satellite Images DEMTerrain

How Terrain Looks Like

3D Models

Poly Model Shaded Model Textured Model

3D Sound

3D Sound

• 3D audio– Sounds are part of the scene graph

– Each sound has a geometric location

• Dolby Pro Logic and Dolby Digital– “5.1” channels:

• 2 main, center, 2 rear surround, subwoofer

Simulation or Physics Engine

• Models behavior in game world

• Collision detection

• FDM in case of Flight Simulator

Artificial Intelligence

• Design of intelligent agents where anintelligent agent is a system that perceives itsenvironment and takes actions whichmaximize its chances of success.

• Computer generated forces or enemies

Network Traffic

• Synchronize game clients

– Game world is a distributed database

– Scene graph derived from game world

• Industry standards

– HLA (High Level Architecture)

– CIGI (Common Image Generator Interface)

– DIS (Distributed Interface Simulation)

Environment

• Visibility range

• Cloud layers, solid or variable patchiness

• Wet & snow-covered surfaces

• Thunderstorm cell, lightning flash & bolt

• Volumetric ground & patchy fog

• Sea states 0 through 9

Multiplayer

Multiplayer on LAN or WAN

Game engine operations

• The Game Engine generates an image from models.

• Converts 3D models into 2D images.

Scene Graph

Rendering Stages

Rendering Process

IMAGE GENERATOR

Component II

Typical IGs

Serious Games’ IG

IG Architecture

Modern Graphics Hardware

• Pipelining– Number of stages

• Parallelism– Number of parallel processes

• Parallelism + pipelining– Number of parallel pipelines

1 2 3

1 2 3

1 2 3

1 2 3

1

2

3

Performance parameters

• Caching

• Update Rate

• Display resolution

Gen Lock & Frame Lock

• Genlock & frame Lock is a technique where the video output of one source, or a specific reference signal, is used to sync other picture sources together.

Anisotropic Filtering

• It is a method of enhancing the image qualityof textures on surfaces that are at obliqueviewing angles with respect to the camera.

Light point capacity

• The number of light points that can be handled.

Levels of detail (LOD)

• LODs are sets of models that represent the same object or terrain area with varying degrees of complexity

Levels of detail (LOD)

Antialiasing

• Antialiasing, as the name suggests, is a technique used to combat an effect known as aliasing.

Addressable moving objects

• The number of moving or animated models per frame.

Blend zones and Alpha transparency level

• Alpha blending is the process of combining a translucent foreground color with a background color, thereby producing a new blended color.

• The number of alpha blending in a frame is blend zones.

• Alpha transparency level is the level of transparency that can be handled.

z-Buffer

• It is the management of image depth coordinates in three-dimensional (3-D) graphics

• It is designed to improve efficiency by selectively choosing which elements in a scene need to be rendered

Iteration rate

• The "physics" iterations performed every second.

Polygonal capacity

• The polygon capacity of an image generator is most often expressed in polygons per second.

• The polygons per second number is divided by any frame rate to yield the polygons in each image.

Other Features

• Output modes

• Number of channels

• Database Type Supported

The secret to good IG

Optimize

Maximize

References

• Presages Creator Manuals• “Game Hardware and Engines” by J. Scott Hofmann• www.wikipedia.org• www.gamedev.net• “Game Development All in One” by Bruno Miguel Teixeira

de Sousa• Quantum 3D IG brochures• Medellin 6000 brochure• Images from www.google.com and www.bing.com search

engines• “3D Engines in games” by Author: Michal Valient• “Introduction to Graphics Hardware and GPUs” by Yannick

and Tom