eNVyMyCara Multi-player Car Racing Game

for Teaching Computer Graphics

Fabio Ganovelli Massimiliano CorsiniVisual Computing Lab, ISTI - PISA

Before starting...

meet:

SoftOGLhow to make your students hate you

2006:: appointed contract professor at University Of Siena for the course of Fundamental of Computer Graphics

7 weeks 42 hours (middle term test and lab included) 9 students

Pisa

Siena

Possible Course Program

Introduction (history, uses, trends...)

general notions (rendering paradigms, hardware...)

tranformations

rasterization

lighting and texture mapping

final project: simple projects using OpenGL...

I could have done this way...still...

Course project:

SoftOGL.sf.netImplementing a working OpenGL-like graphics API

benefit: to make the students gain a solid understanding ofCG algorithms

namespace softogl{ namespace impl{ // DDA segment rasterization // void DDASegmentRasterization(Segment2d s,int size=1){ // .................implementation.................. // } // Bresehnam segment rasterization // void BresenhamSegmentRasterization(Segment2d s,int siz = 1){ // .................implementation.................. // } // Polygon Filling // void PolygonFilling(Polygon2d p){ // .................implementation................. // } // }// end impl namespace sdk{ // ...}// end sdk};

students:iplementation

me: environmentand SDK tools

SoftOGL

first day, Feb 27, 2006

last day, April 9, 2006

Mistakes

programming skills :(

little sense of achievement :(

way too much work for the number of credits given by the CG course :(

2007:: My collegue Massimiliano was appointed contract professor at University Of Ferrara

Pisa

Siena

Ferrara

Goals of the course project

Give them a reachable target

Generate cooperation and competition between students

Make them learn some CG

Set the students in a common framework without too much specialized tasks

Do not burden them with non-CG problems

yeah..

eNVyMyCar.sf.net

a Multi-player Car Racing Game for

Teaching Computer Graphics

Concept

A software framework implementing a simple multi-player car-racing game over a LAN

Student's task: implement a client for the game:

RENDER the scene interactively

take the user input

doesn't it remind you something?...

Goals of the course project

Give them a reachable target

Generate cooperation and competition between students

Make them learn some CG

Set the students in a common framework without too much specialized tasks

Do not burden them with non-CG problems

Envy factor

At any moment, a client may send a snapshot of its view to all the others connected

NVMC_Server

Goals of the course project

Give them a reachable target

Generate cooperation and competition between students

Make them learn some CG

Set the students in a common framework without too much specialized tasks

Do not burden them with non-CG problems

Elements of the SceneStatic

The street

The buildings

The trees

Tunnels...

Dynamic (state)

The cars

sun position

p0

p0

p0

p1

p2

p3

p4

p5 p

6

p7

\

NVMC Architecture

#include <game_client.h>extern NvmcClient cli;

void draw_scene(){cli.UpdateScene();

/* .....*/

cli.UpdateScreenshots();}

void process_event(....){switch(..) {

case ... : cli.Command(COMMAND_INCREASE_SPEED); break;case ... : cli.Command(COMMAND_DECREASE_SPEED); break;case ... : cli.Command(COMMAND_TURN_LEFT); break;case ... : cli.Command(COMMAND_TURN_RIGHT); break;case ... : cli.Command(COMMAND_BRAKE); break;case ... : cli.Command(SEND_SCREENSHOT);break;

}}int launch_viewer(){......}

making a circuit

NVMC provides a simple code to convert a bitmap in a circuit

Implementation

the simpler the better:

C++

VCG for geometric concepts (vcg.sf.net)

QT for networking and multi threading

whatever you/they like for GUI (sdl -glut -qt)

used with: Windows ( .net), Mac (xcode), Linux (eclipse/Kdevelop)

Goals of the course project

Give them a reachable target

Generate cooperation and competition between students

Make them learn some CG

Set the students in a common framework without too much specialized tasks

Do not burden them with non-CG problems

Incremental learning

Basic features (the minimum required)

geometric transformations

lighting

texturing terrain and buildings

rollingsteering

putting on its place

scale place the carin its current position

Make it interesting

The students are given a list of possible features to implement, e.g.:

impostors for the trees

motion blurring for speed

lens flares

dynamic reflections on the car

projective texturing for the car lights

Each feature brings some points

Encourage clean code

code must be modular: if student A includes features written by student B it is a bonus for both

Q: How do you know who did it first?

A1: trust them

source code is open: envymycar.sf.net

CVS repository

A2: have a look to the commit timestamps

Goals of the course project

Give them a reachable target

Generate cooperation and competition between students

Make them learn some CG

Set the students in a common framework without too much specialized tasks

Do not burden them with non-CG problems

Conclusion

NVMC was used in 2 courses in 2006 and in one course in 2007 (just finished)

The feedback of the 39 students of these courses was very satisfactory (after the usual it's-too-much-work default complaint)

problems can be in the background knowledge of c++ and the bit of Stl they need to know.

Future Work

Implementation is quite poor:

no collision detection

only flat circuits

...other things we can put there having time..

Set up a public NVMC server for students of different campus to show off

Thanks!

http://envymycar.sf.net

thanks to:all our students who worked with nvmcRenata Otfinoswka for all the drawings