Hello, I''ve a problem with the spotlight. If I slowly change e.g. the cutoff angle, the light cone doesn''t seem to grow or melt smoothly, but in big steps or perhaps only alternatig between on and of. And I''ve a simular problem if I change the direction of an spotlight, it seems to jump in steps of 90 degrees. Could it be that its a graphic card Problem. I''m working with a Vodoo3 2000 AGP driver version 1.07.00 (if I''ve found the right number out of all this stuff, I think its from dec 000) for Win98. Could some of you please take the code I''ve posted, compile it and run it. And tell me wheter there is a smooth changing of the light cone, until it reaches 90 degrees, and then set it back to 0 degrees. Or tell me if there is a mistake in my code. This should set up an square that is centered to the light (and view) position, 4 units "in" the screen. If the code runs to fast uncomment the Sleep function (and play around with it). #include windows.h #include gl/gl.h #include gl/glu.h #include gl/glut.h int WINAPI WinMain( HINSTANCE hInstance, // Handle der aktuellen Instanz HINSTANCE hPrevInstance, // Handle der vorher gehenden Instanz (?allways zero?) LPSTR pszCmdLine, // pointer to command line (if prog was started over a command line) int nCmdShow // Fensterstatus ); void init(); void display(); void keyboard(unsigned char key, int x, int y); void reshape(int w, int h); int WINAPI WinMain( HINSTANCE hInstance, // Handle der aktuellen Instanz HINSTANCE hPrevInstance, // Handle der vorher gehenden Instanz (?allways zero?) LPSTR pszCmdLine, // pointer to command line (if prog was started over a command line) int nCmdShow // Fensterstatus ) { glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGBA); glutInitWindowSize (450, 450); glutInitWindowPosition (150, 200); glutCreateWindow("GL_Test"); init (); glutDisplayFunc(display); glutReshapeFunc(reshape); glutMainLoop(); return 0; } void init(void) { glClearColor (0.0, 0.0, 0.0, 0.0); glShadeModel (GL_SMOOTH); glEnable(GL_NORMALIZE); glEnable(GL_LIGHTING); glEnable(GL_CULL_FACE); GLfloat lightBlack[4] ={0,0,0,0}; glLightModelfv( GL_LIGHT_MODEL_AMBIENT, lightBlack); // sets ambient light to black GLfloat white[4] = {1.0,1.0,1.0,1.0}; glLightfv(GL_LIGHT1, GL_DIFFUSE, white); GLfloat pos[4] = {0.0,0.0,0.0,1.0}; // make it positional light glLightfv(GL_LIGHT1, GL_POSITION, pos); glLighti(GL_LIGHT1, GL_SPOT_CUTOFF, 20); GLfloat dir[3] = {0.0f,0.0f,-1.0f}; glLightfv(GL_LIGHT1, GL_SPOT_DIRECTION, dir); glEnable(GL_LIGHT1); glEnable(GL_COLOR_MATERIAL); } void display(void) { glLoadIdentity(); glClear(GL_COLOR_BUFFER_BIT); static GLint cutoffAngle = 10; GLint A[] = {-2,-2,-4}; GLint B[] = {2,-2,-4}; GLint C[] = {2,2,-4}; GLint D[] = {-2,2,-4}; glLighti(GL_LIGHT1, GL_SPOT_CUTOFF, cutoffAngle); glBegin(GL_QUADS); glColor3f(1.0f,0.5f,0.5f); glNormal3i(0,0,1); glVertex3iv(A); glVertex3iv(B); glVertex3iv(C); glVertex3iv(D); glEnd(); glutSwapBuffers(); if ( (cutoffAngle++)>90) cutoffAngle = 0; // Sleep(10); glutPostRedisplay(); }

you have to tesselate your poly in order to have a nice looking spotlight! a few weeks ago i open a thread on the subject :
http://www.gamedev.net/community/forums/topic.asp?topic_id=41186

nice coding


lunasol =(star*)malloc(lunaRadius*sizeof(sun));

Thanks, it falls like leaves in front of my eyes. Just forgot about this, will try out soon.

Greetings Ben