Jean-Marc Vézien International Masters in biometrics

3D modeling and Augmented Reality

1

OPENGL introduction

This is a “hands-on” session of OpenGL. Using the template project called graphicsTest,

you will progressively build your own OpenGL application.

Question 1: Getting started

Download the GraphicsTest projet. Make sure GLUT is installed on your computer. Open

the graphicsTest.cpp file. Identify :

The rendering routine

The initialization routine

The interaction routines (mouse, keyboard)

Why is the graphics window blue ? How do you quit the program ?

Question 2: 2D drawing (Orthographic mode)

Important : For 2D drawing, set the GL_PROJECTION with glOrtho() in GLUTResize()

func !

Using the proper calls in GL_LINES mode:

Draw a red triangle in the middle of the window

Draw a green “spring”:

Question 3: Drawing in 3D

The skeleton program contains everything to draw a cube… but you need to change and edit a

few things!

Identify the routine that draws a cube and insert a call at the right location

The coordinates of the cube vertices need to be initialized !

Jean-Marc Vézien International Masters in biometrics

3D modeling and Augmented Reality

2

The GLUTResize function needs to be changed. No calls to glOrtho() here !

Notice the lighting instructions and camera positioning. Try to comment out the calls to

glTranslatef() and glRotatef() and look at the result.

Question 4: modify the camera view

Starting from the result of question 3, change the GLUTMotion() routine to capture the mouse

motion, so that :

- A horizontal motion with left button pressed rotates the object around vertical axis

- A vertical motion with left button pressed rotates object around horizontal axis

- Any mouse motion with Ctrl + button pressed zooms in and out (translation of

camera)

Question 5: Animation

Exploiting question 4, design an automatic animation where the cube rotates around

the Z axis at the speed of 10 degrees per second.

Animate the cube so that it rotates for 5 seconds around the Z axis, then around the X

axis for for 5 more seconds, then cycle again.

Note: You must make use of glutTimerFunc() to make sure the drawing takes place at the

correct time.