Proyecto unidad IV

Investigue sobre:

• Como activar las fuentes de luz en opengl
• Como Calcular la normal para cada vertice en opengl
• 3ejemplos de codigo en opengl manejando iluminación

Haga un resumen y publique en su blog


Entrega: publicado en el Blog el Lunes 12 de Noviembre

Referencias sugeridas:
http://dmi.uib.es/~josemaria/OpenGL/Iluminacion.html

http://sabia.tic.udc.es/gc/Contenidos%20adicionales/trabajos/Opengl/tut_opengl_ilumin_raton_text/iluminacion.htm

http://www.google.com.mx/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=3&ved=0CC4QFjAC&url=http%3A%2F%2Fgsii.usal.es%2F~igrafica%2Fdescargas%2Ftemas%2FTema08.ppt&ei=gF-ZUK3REtDWigKq54C4Dg&usg=AFQjCNG6D5TvrjnWMus1fmKYN0ygPJ5nuQ


/* sphere.c */
/* E. Angel, Interactive Computer Graphics */
/* A Top-Down Approach with OpenGL, Third Edition */
/* Addison-Wesley Longman, 2003 */
/* Recursive subdivision of cube (Chapter 6). Three display
modes: wire frame, constant, and interpolative shading */
/*Program also illustrates defining materials and light sources
in myiit() */
/* mode 0 = wire frame, mode 1 = constant shading,
mode 3 = interpolative shading */
#include <stdlib.h>
#include <GL/glut.h>
　
typedef float point[4];
/* initial tetrahedron */
point v[]={{0.0, 0.0, 1.0}, {0.0, 0.942809, -0.33333},
{-0.816497, -0.471405, -0.333333}, {0.816497, -0.471405, -0.333333}};
static GLfloat theta[] = {0.0,0.0,0.0};
int n;
int mode;
　
void triangle( point a, point b, point c)
/* display one triangle using a line loop for wire frame, a single
normal for constant shading, or three normals for interpolative shading */
{
if (mode==0) glBegin(GL_LINE_LOOP);
else glBegin(GL_POLYGON);
if(mode==1) glNormal3fv(a);
if(mode==2) glNormal3fv(a);
glVertex3fv(a);
if(mode==2) glNormal3fv(b);
glVertex3fv(b);
if(mode==2) glNormal3fv(c);
glVertex3fv(c);
glEnd();
}
void normal(point p)
{
/* normalize a vector */
double sqrt();
float d =0.0;
int i;
for(i=0; i<3; i++) d+=p[i]*p[i];
d=sqrt(d);
if(d>0.0) for(i=0; i<3; i++) p[i]/=d;
}

void divide_triangle(point a, point b, point c, int m)
{
/* triangle subdivision using vertex numbers
righthand rule applied to create outward pointing faces */
point v1, v2, v3;
int j;
if(m>0)
{
for(j=0; j<3; j++) v1[j]=a[j]+b[j];
normal(v1);
for(j=0; j<3; j++) v2[j]=a[j]+c[j];
normal(v2);
for(j=0; j<3; j++) v3[j]=b[j]+c[j];
normal(v3);
divide_triangle(a, v1, v2, m-1);
divide_triangle(c, v2, v3, m-1);
divide_triangle(b, v3, v1, m-1);
divide_triangle(v1, v3, v2, m-1);
}
else(triangle(a,b,c)); /* draw triangle at end of recursion */
}
void tetrahedron( int m)
{
/* Apply triangle subdivision to faces of tetrahedron */
divide_triangle(v[0], v[1], v[2], m);
divide_triangle(v[3], v[2], v[1], m);
divide_triangle(v[0], v[3], v[1], m);
divide_triangle(v[0], v[2], v[3], m);
}

void display(void)
{
/* Displays all three modes, side by side */
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
mode=0;
tetrahedron(n);
mode=1;
glTranslatef(-2.0, 0.0,0.0);
tetrahedron(n);
mode=2;
glTranslatef( 4.0, 0.0,0.0);
tetrahedron(n);
　
glFlush();
}
　

void myReshape(int w, int h)
{
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (w <= h)
glOrtho(-4.0, 4.0, -4.0 * (GLfloat) h / (GLfloat) w,
4.0 * (GLfloat) h / (GLfloat) w, -10.0, 10.0);
else
glOrtho(-4.0 * (GLfloat) w / (GLfloat) h,
4.0 * (GLfloat) w / (GLfloat) h, -4.0, 4.0, -10.0, 10.0);
glMatrixMode(GL_MODELVIEW);
display();
}

　

void myinit()
{
GLfloat mat_specular[]={1.0, 1.0, 1.0, 1.0};
GLfloat mat_diffuse[]={1.0, 1.0, 1.0, 1.0};
GLfloat mat_ambient[]={1.0, 1.0, 1.0, 1.0};
GLfloat mat_shininess={100.0};
GLfloat light_ambient[]={0.0, 0.0, 0.0, 1.0};
GLfloat light_diffuse[]={1.0, 1.0, 1.0, 1.0};
GLfloat light_specular[]={1.0, 1.0, 1.0, 1.0};
/* set up ambient, diffuse, and specular components for light 0 */
glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
/* define material proerties for front face of all polygons */
glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient);
glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
glMaterialf(GL_FRONT, GL_SHININESS, mat_shininess);
glShadeModel(GL_SMOOTH); /*enable smooth shading */
glEnable(GL_LIGHTING); /* enable lighting */
glEnable(GL_LIGHT0); /* enable light 0 */
glEnable(GL_DEPTH_TEST); /* enable z buffer */
glClearColor (1.0, 1.0, 1.0, 1.0);
glColor3f (0.0, 0.0, 0.0);
}
　

void main(int argc, char **argv)
{
n=5;
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(500, 500);
glutCreateWindow("sphere");
myinit();
glutReshapeFunc(myReshape);
glutDisplayFunc(display);
glutMainLoop();
}