Change the shading of object

Sat Mar 17, 2012 11:01 pm

In this example we change the shading model of object affected by light source from its default which is GL_SMOOTH to GL_FLAT.

Code:: #include <GL\glut.h> #include <math.h> // For math routines (such as sqrt & trig). GLdouble radius=1.5; GLfloat qaWhite[] = {1.0, 1.0, 1.0, 1.0}; //White Color GLfloat qaRed[] = {1.0, 0.0, 0.0, 1.0}; //Red Color // Set lighting intensity and color GLfloat qaAmbientLight[] = {0.1, 0.1, 0.1, 1.0}; GLfloat qaDiffuseLight[] = {1, 1, 1, 1.0}; // Light source position GLfloat qaLightPosition[] = {-2, 0, -9.5, 1};// Positional Light GLfloat qaLightDirection[] = {1, 1, 1, 0};// Directional Light void display(void); void reshape(int x, int y); void initLighting() { // Add smooth glShadeModel(GL_FLAT); // Enable lighting glEnable(GL_LIGHTING); glEnable(GL_LIGHT0); // Set lighting intensity and color glLightfv(GL_LIGHT0, GL_AMBIENT, qaAmbientLight); glLightfv(GL_LIGHT0, GL_DIFFUSE, qaDiffuseLight); glLightfv(GL_LIGHT0, GL_POSITION, qaLightPosition); //////////////////////////////////////////////// //glLightf( GL_LIGHT0, GL_CONSTANT_ATTENUATION, 0.2f ); glLightf( GL_LIGHT0, GL_LINEAR_ATTENUATION , 0.5f ); //glLightf( GL_LIGHT0, GL_QUADRATIC_ATTENUATION , 0.009f ); } void keyboard(unsigned char key, int x, int y) { if (key == 'l' || key == 'L') { glEnable(GL_LIGHTING); } else if (key == 'd' || key == 'D') { glDisable(GL_LIGHTING); } } int main (int argc, char **argv) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH ); glutInitWindowSize(750,750); glutCreateWindow("Teapot -light attenuation"); initLighting(); glutDisplayFunc(display); glutKeyboardFunc(keyboard); // Register keyboard callback glutReshapeFunc(reshape); glutMainLoop(); return 0; } void display(void) { glMatrixMode(GL_MODELVIEW); // clear the drawing buffer. glClear(GL_COLOR_BUFFER_BIT); // clear the identity matrix. glLoadIdentity(); glTranslatef(0.0,0.0,-5.0); glPushMatrix(); glTranslatef(0.0,0.0,-2.0); // Set material properties glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, qaRed); glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, qaRed); glutSolidTeapot(radius); glPopMatrix(); glFlush(); glutSwapBuffers(); } void reshape(int x, int y) { if (y == 0 || x == 0) return; glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(39.0,(GLdouble)x/(GLdouble)y,0.6,40.0); glMatrixMode(GL_MODELVIEW); glViewport(0,0,x,y); //Use the whole window for rendering }

Attachments

: smooth_shade.png (63.01 KiB) Viewed 8596 times

: flat_shade.png (20.27 KiB) Viewed 8596 times

Change the shading of object

Change the shading of object

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