Princípios de Implementação de
Jogos com Modelos 3D em C++
Marcelo Johann
II Semana de Tecnologia
Departamento de Tecnologia da UNIJUÍ
Outline for Introduction
Introduction - how games evolved?
Motivation - why teaching games?
Goals - what to get from the course?
Methodology - what’s gonna happen here?
Background - what are you expected to know?
Infrastructure - HW and SW that we need…
Interaction - Keep questioning me…
Contents…
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 2
Introduction
• Back to the 80’s… Galaga
Moon Patrol
http://spacemul.emufrance.com/screen.php3?id=13&lettre=
G&lang=eng
http://www.mobygames.com/game/shots/gameId,575/
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 3
Introduction
• 1986: first 3D games appearing…
Alien 8
http://spacemul.emu-france.com/screen2.php3?id2=14687&lang=eng
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 4
Introduction
• And today…
Half Life 2
http://www.rottentomatoes.com/g/pc_games/half_life_2/images.php
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 5
Introduction
Mobil 1 British Rally
Championship
http://www.mobygames.com/game/shots/p,3/gameId,3758/
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 6
Introduction
• Evolution of computer games
From 1D, 2D to complex 3D universe
• Needs: hardware, software, artwork
• Trends:
Continuous hardware evolution
Engines - higher abstraction levels
Professional programming techniques
Extensive visual work -> $$$
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 7
Motivation
• Computing requires Programming
• Learning how to program is not simple
• Difficulty to begin and to be professional
time, interaction, experience
• Need for problems that justify complex
programming languages and techniques
Games: lot of fun and
learning potential
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 8
Goals
• Learning and Practicing Object-Oriented
Programming
– Professional C++, modular, O-O
• Learning technologies for the development
of games that use 3D models
– Engines, 3D modeling
– Game architecture and timing
– Game techniques
with many other applications
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 9
Methodology
• Hands-on
• based on step-by-step examples
Test/Ask about everything
• At the beginning:
– No class definitions!
– Avoid using complex C++ constructions;
– Emphasis on productivity
• Complexity is introduced when required
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 10
Background
• Structured programming
• C language
• Basic data structures
Not necessary:
– experience on C++ programming
– advanced computer graphics
Ask about people’s background
Should ask anything that you don’t know!
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 11
Infrastructure
• Fast computer with:
OpenGL, “Accelerated” graphic card
Linux with gcc, g++, make (Mac OS X now)
• Gizmo3D
http://www.tooltech-software.com/
• Crystal Space
http://sourceforge.net/projects/crystal
• Open Dynamics Engine
http://ode.org
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 12
Outline for Contents
Introduction
Main engine - Gizmo3D structure and start up
3D modeling - from triangles to transforms
Events - how to read keyboard input
Logic - game actions and control
Simulation loop - structure, moves, timing
Terrains and LODs - levels of detail
Animation / levels - frame, skeleton concepts
Collision and Physics - world behavior
Things that we did not consider…
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 13
Main Engine
Gizmo3D
• Features
• Tutorial slides:
* skip gzApplication methods and task
* skip gzGeometry and gzTransform
* stop at the Expanding Scene
• start with exe00
• Essential constructions of O-O
– Just Object *pt = new Object(...);
– And result = pt -> method(...);
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 14
3D Modeling
Surfaces
• Triangles
- the easiest way
* exe01
• Material
• Lighting
* http://www.xmission.com/~nate/tutors.html
* exe02 and exe03
* slides Gizmo Material
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 15
3D Modeling
• Texture
* gizmo databases
* exe04 to exe11
(0,1)
(1,1)
(0,0)
(1,0)
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 16
3D Modeling
• Transformations
* gizmo slides 66 to 76
* exe12 to exe14
• Cloning
* exe15
• Groups
* exe17 a exe19
• Billboard
* gizmo’s billboard and my tests
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 17
Control Events
•O-O
* exe20 to exe21
• app->run and onTick
* gizmo slides 29 a 36
* exe22
•app->run and onIdle
onTick and onIdle have to call refreshWindow
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 18
Logic of the Game
Logic Model may be different from 3D
• First City
* exe25
• Estoque: “Sokoban”
* estoque
• Network
* show socketControl in drive44
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 19
Simulation Loop
void MyApp::onIdle()
{
if(m_win->m_key_left_is_down)
car1->changeDirection(-1,m_win->getFrameRate());
if(m_win->m_key_right_is_down)
car1->changeDirection(1,m_win->getFrameRate());
if(m_win->m_key_up_is_down) car1->speedup(1.3f);
if(m_win->m_key_down_is_down) car1->slowdown(1.3f);
car1->move( 1, m_win->getFrameRate());
car2->move(m_win->getFrameRate());
car3->move(m_win->getFrameRate());
cam->move(m_win->getFrameRate());
m_win->refreshWindow();
Drive exe44
}
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 20
Playing with Models
Take drive44
Take models from: www.3dtotal.com
* sofa.3ds
* speedboat.3ds
* chevi_camaro.3DS
* tiebomber.3ds
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 21
Terrain and LOD
terrain.txt of the drive44
• Window
* gizmo’s window shows LOD
Other example is broken (62)
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 22
Animation and Levels
• Frame Animation
Map file of Crystal Space Flying Brick (exe57)
Crystal Space map file
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 23
Skeleton Animation
Types of Joints Open Dynamics Engine
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 24
Animation
Character
Lara Croft
http://www.3dkingdom.org
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 25
Animation Control
Frame sequences
Pony Tail with a math model
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 26
Collision
• gzIntersector
• intersect(stuff,…)
• getResults
NO!

OK
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 27
Collision
• Car corners
• Simple Geometry

UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 28
Collision
• To collide is hard
• To know what to do next
is even harder
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 29
Collision
• stairs and floor
• vertical versus horizontal
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 30
Physics
• How about collision with other objects?
• This is very hard to handle…
Model what happens in a physical system
* example odetest - from ODE’s test_buggy
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 31
Missing
• Sound
• Animation Control
• Explosions, particles
• Artificial intelligence
Other Engines and Game Resources:
www.3dlinks.com
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 32
Thanks to
• PUCRS - Uruguaiana
Marcus Kindel ([email protected])
Cintya Bortolazzo
• UFRGS - Computação Gráfica
Luciana Nelel (www.inf.ufrgs.br/~nedel)
[email protected], pelo ODE
• Gizmo3D & game community
Anders Modén ([email protected])
Esteban G. Clua ([email protected])
UNIJUÍ 2004 - Marcelo Johann – Mini Curso de Games : 33
Princípios de Implementação de
Jogos com Modelos 3D em C++
Marcelo Johann
[email protected]
www.inf.ufrgs.br/~johann
II Semana de Tecnologia
Departamento de Tecnologia da UNIJUÍ