Question

请OpenGL高手调试一下我的程序

#include "gl/freeglut.h"
void DisplayScene ();
void myDisplay ()
{

DisplayScene ();
glutSwapBuffers();
glutPostRedisplay();
}
void DisplayScene ()
{
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glColor3f(1.0f,0.5f,0.5f);
glLoadIdentity();
gluLookAt (0.0f,0.0f,10.0f,0.0f,0.0f,-100.0f,0.0f,1.0f,0.0f);
glBegin (GL_TRIANGLES);
glVertex3f(10.0f,0.0f,0.0f);
glVertex3f(0.0f,10.0f,0.0f);
glVertex3f(-10.0f,0.0f,0.0f);
glEnd();
//glFlush();
}
void main (int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(800,600);
glutInitWindowPosition(100, 100);
glutCreateWindow("My OpenGL");
glutDisplayFunc(myDisplay);
glutMainLoop();
}
为什么我什么都看不到 ？

Answer 1

改成gluLookAt (0.0f,10.0f,0.0,0.0f,0.0f,-100.0f,0.0f,1.0f,0.0f);就能看到一个边；你得程序没有定义投影
glMatrixMode(GL_PROJECTION);
glLoadIdentity ();
gluPerspective(60,1,0,100);
gluLookAt (0.0f,10.0f,30.0,0.0f,0.0f,-100.0f,0.0f,1.0f,0.0f);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity ();