Chapter 14
Simulation, Graphics, Gaming
and Other Applications
Chapter Goals – THE BIG SLICES
•Models and Simulation
•Computational Biology
•(Complex) Computer Graphics
•Computer Gaming
2
Chapter Goals
•Models and Simulation
•
•
•
•
•
Complex Systems
Continuous and Discrete simulation
Object-oriented design and building models
Queuing systems
Weather and Seismic models
3
Chapter Goals
•Computational Biology
•
•
•
•
Bioinformatics
Computational Biomodeling
Protein Modeling
Molecular Modeling
4
Chapter Goals
•Computer Graphics
•
•
•
•
•
The CREATION of complex images
CAD
Fractal and Other Techniques
Light and Rendering
Movement
5
Chapter Goals
•Computer Gaming
• The LAYERS
• Design and Development
• Game Programming
6
Complexity!
• Some real-world systems are complicated
• We want to model complex systems to:
– better understand them
– predict the future
14-7
What is a Model?
• An Abstraction of a Real World System
– A representation of the objects or quantities
within the system
(Noun, the Data)
– and the rules that govern the interactions
between them
(Verb, the Code & Algorithms)
– Systems that are best suited to being simulated
are dynamic, interactive, and complicated
14-8
What Is Simulation?
• Simulation is RUNNING a model to PREDICT the
results of experimental CHANGES in the system
• Doing “What If” analysis
“What happens if I change this?
“What happens if I don’t?”
14-9
Kinds of Models
13-10
Kinds of Models
• There are 2 Big Slices:
–Discrete Models
–Continuous Models
13-11
Kinds of Models
•Discrete event simulation
•Made up of entities, attributes, and events
– Entity The representation of some object in the
real system
– Attribute Some characteristic of a particular
entity
– Event An interaction between entities
12
Air Traffic – A Discrete Model
• Air Traffic in USA
– Planes are
objects
– Attributes
include speed
– Events are
planes entering
and leaving
airspace
14-13
Kinds of Models
• Continuous simulation
– Treats time as continuous
– Expresses changes in terms of a set of differential
equations that reflect the relationships among the
quantities in the model
– Meteorological models falls into this category
14
Hurricanes – A Continuous Model
14-15
A Continuous Models and FEA
• Finite Element Analysis (FEA): Dividing a
volume of space into small cubes, which
contain our quantities of interest
• Many Continuous Models Use FEA
14-16
Queuing Systems
13-17
Queuing Systems
Queuing system:
A particular kind of discrete-event model
The system is made up of
– Server objects
– Clients objects
– Queues of clients to be served
Please
Wait….
18
Queuing Systems
•Can you name at least three queuing systems
that you interact with every day?
Please
wait!
19
Queuing Systems
• To construct a queuing model, we must know
– The number of events and how they affect the system in
order to determine the rules of entity interaction
– The number of servers
– The distribution of arrival times in order to determine if an
entity enters the system
– The expected service time in order to determine the
duration of an event
20
Queuing Systems
•Given a hypothetical service station, what are
•
the events?
•
the number of servers?
•How can you determine
•
distribution of arrival time?
•
expected service time?
21
Meteorological
Models
13-22
Weather – A Continuous Model
14-23
Meteorological Models
Meteorological models
•Models based on the time-dependent partial
differential equations of fluid mechanics and
thermodynamics
•Initial values for the variables are entered from
observation, and the equations are solved to
define the values of the variables at some later
time
24
Meteorological Models
How much
math
does it
take to
be a
meteorologist?
25
Weather – A Continuous Model
14-26
Hurricane Tracking
(GFDL)
Geophysical
and Fluid
Dynamics
Laboratory
Figure 14.2
Improvements in
hurricane models
27
Computational
Biology
13-28
Computational Biology
The application of computer science to problems in
biology
(or is it the other way around??  )
Encompasses:
29
•
bioinformatics
•
computational biomodeling
•
molecular modeling
•
protein structure prediction
Computational Biology
•Bioinformatics
• Discovering and Processing DNA sequences
• Human Genome Project and Others
30
Computational Biology
•Computational Biomodeling
• The simulation of biological systems
Knees
Cell Wall Protein
31
Cell Metabolism
Computational Biology
•Protein Structure Modeling
• Simulating 3-Dimensional Structure and
Function of Protein Molecules
32
Computational Biology
•Molecular Modeling
• Simulating Structure and Function of Chemical
Molecules (usually drug discovery)
33
Graphics
13-34
“Traditional” Graphics
•Technical or Engineering Graphics
•Originally a language of communication for engineers,
designers, and architects
•Computer-Aided Design (CAD)
•A system that uses computers with advanced graphics
hardware and software to create precision drawings or
technical illustrations
35
Graphics for Computer Aided Design
Figure 14.3
Geometric
modeling
techniques
36
Simulating Light
Ray Tracing
The projection of a 3-Dimensional model onto
a 2-Dimensional computer screen
37
Simulating Light
Illumination model
Used to simulate the interaction of light with objects
Objects are
Shaded
Rendered
38
Fractal Techniques
13-39
Modeling Complex Objects
What
graphics
challenges
are
inherent
in
natural
landscapes
?
Figure 14.5 A natural computer generated landscape
40
Fractal Terrain
Fractal terrains via
Midpoint subdivision
(Fractal Mountains)
41
“Cell” Models
13-42
Earth, Wind, Fire and Water
•Cell-Based Models
•
•
•
•
•
•
Like continuous FEA models
Uses quantities and laws from physics
“How is a hurricane like a glass of water?”
Or a Cloud?
Or Fire?
Or Smoke?
14-43
Cell Models
Figure 14.7 Water pouring into a glass
44
Cell Models
Figure 14.8 Cellular automata-based clouds
45
Modeling Complex Objects
Cell Models
Figure 14.9 A campfire
What do clouds, smoke and
fire have in common?
46
Gaming
13-47
Computer Gaming
• A simulation of a virtual world
• Usually based on the rules of our real world
• Some rules can be bent
• Some rules can be broken
•
48
Computer Gaming
•Game designers need to know the LAYERS:
–
–
–
–
Computer graphics
Artificial intelligence
Human-computer interactions and simulation
Software engineering (management of large complex
projects)
– Computer security
– Laws of physics relating to gravity, elasticity, light & sound
49
Creating the Virtual World
•Game engine:
•A software system within which games can be created
(A tool to create games)
•Analogous to a compiler
(A tool to create programs)
•(Similarly, some people write engines, some people write games)
50
A Game Engine Provides
•A rendering engine for graphics
•A physics engine for collision detection and dynamics
•A sound-generating component
•A scripting language apart from the code driving the
game
•Character Animations
•Algorithms (e.g., path-finding algorithms)
•Artificial intelligence algorithms
(NonPlayerCharacters)
51
Game Engine Scene Graphs
• Where is your toothbrush?
• Where did you park your car?
• You use a Scene Graph to find these things in your
brain first
• A way to store object
locations and other
data in memory
52
Soft Skills Needed
•High Quality Game Design and Development Requires
Effective Use of “Soft Skills”:
• Effective collaboration with designers, programmers, and
artists on various technical ideas throughout entire game design
and development process
• Flexibility and adaptability as the game design constantly
evolves and changes throughout the development and
production process
53
Game Programming
•After all the design decisions have been finalized,
programmers produce the code to create the virtual
world of the game
•Popular languages include: C++, Java, and C
•Some well-established game engineers have created
custom languages based on their games, e.g., Epic
Game’s UnrealScript for the Unreal Game
54
Game Programming
API’s and Platforms
•Application Programmers Interface (API): A set of
commands used in a programming language to
interface with another piece of software
•Game Engines provide APIs to help developers with
key programming tasks
•Game Engines usually target a particular platform
such as PC or Xbox or PlayStation, etc
55
Game Programming
The “Game Loop”
•Coding process begins with the creation of the “game
loop”
•Game loop is responsible for managing the game
world, regardless of any input from the user
•For example, the game loop might update enemy
movement in the game or check for victory/loss
conditions
•Basically, the game loop manages the simulation
56
Game Programming
Teams and Roles
•Large design teams have different programmers
focus on different aspects of the game
•Thus, you might find yourself working as:
– A Junior Engine programmer writing and
maintaining code for the game loop or a
– A 3D Software Programmer designing and
implementing the 3D graphics component or a
– A User-Interface Programmer working on the APIs
in the game engine
– Etc…
57