This document discusses lighting in OpenGL. It explains the different types of lights including ambient, diffuse, specular, and emissive light. It provides examples of how original object color is affected by adding different light types. The document also outlines the steps for using lights in OpenGL which includes enabling lighting, selecting light sources, setting light and material properties, defining normals, and drawing polygons.

1. Lighting Basic

2. 1. Default View in OpenGL

3. 2. When Lighting is Enabled

4. 3. When Light Source is Disabled

5. 4.1 Different Types of Light
Specular
Diffuse
Ambient

6. 4.2 Different Types of Light
● Specular: Sets the color for highlights
● Diffuse: is the color of the object when it is
illuminated
● Ambient: is the color of the mesh when it's not
illuminated
● Emissive: is the type of light which is being
emitted by an object

7. 5. Color Used in Example
Original Material Ambient Diffuse
Specular Emissive

8. 5.1 Example
Wireframe 1. Original Color 2. Original Color + Ambient
3. Original Color + Ambient
+ Diffuse
4. Original Color + Ambient
+ Diffuse + Specular
5. Original Color + Ambient
+ Diffuse + Specular +
Emissive

9. 6. Using Light(s) on OpenGL
(a) Enable lighting
(b) Select light source(s)
(c) Set light position
(d) Set light color
(e) Set material color
(f) Set normal to the polygon
(g) Draw polygon

10. 6(a) Enable Lighting
glEnable(GL_LIGHTING);

11. 6(b) Select Light Source(s)
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
Light Sources: 0 - 7

12. 6(c) Set Light Position
// Set the light position
GLfloat lightPosition[] = { 0.5, 1.0, 1.0, 0.0 };
glLightfv(GL_LIGHT0, GL_POSITION, lightPosition);

13. 6(d) Set Light Color
GLfloat colorWhite[] = { 1.00, 1.00, 1.00, 1.0 };
GLfloat colorDarkGray[] = { 0.10, 0.10, 0.10, 1.0 };
GLfloat colorLightGray[] = { 0.75, 0.75, 0.75, 1.0 };
glLightfv(GL_LIGHT0, GL_AMBIENT, colorDarkGray );
glLightfv(GL_LIGHT0, GL_DIFFUSE, colorLightGray);
glLightfv(GL_LIGHT0, GL_SPECULAR, colorWhite );

14. 6(e) Set Material Color
GLfloat colorWhite[] = { 1.00, 1.00, 1.00, 1.0 };
glMaterialfv(GL_FRONT, GL_SPECULAR, colorWhite);
glMaterialf(GL_FRONT, GL_SHININESS, 50.0);
glColor3f(0.40, 0.61, 0.94);
Shininess: 0 - 128

15. 6(f) Set Normal to the Polygon
glBegin(GL_QUADS);
glNormal3f(0, 1, 0);
glVertex3f(0, 0, 0);
glVertex3f(3, 0, 0);
glVertex3f(3, 3, 0);
glVertex3f(0, 3, 0);
glEnd();

16. 6(g) Draw Polygon
glBegin(GL_QUADS);
glNormal3f(0, 1, 0);
glVertex3f(0, 0, 0);
glVertex3f(3, 0, 0);
glVertex3f(3, 3, 0);
glVertex3f(0, 3, 0);
glEnd();

17. Another Example
No shininess Shininess: 50.0

18. </end>