OpenGL模拟宇宙场景，可是无法显示材质

OpenGL模拟宇宙场景，可是无法显示材质，背景是贴图，三个球是加了材质的，但是一旦运行，三个球的颜色一闪而过，变了黑色。。。各位大侠。。。求指教啊。。。我可是在贴图那里加了法线的啊。。。
主要代码：
GLfloat light1_position[] = {2.0f, 5.0f, 2.0f, 1.0f};  
  GLfloat light1_diffuse[] = {1.0f, 1.0f, 1.0f, 1.0f}; 

  glLightfv(GL_LIGHT1, GL_POSITION, light1_position); 
  glLightfv(GL_LIGHT1, GL_DIFFUSE, light1_diffuse); 
 
glLightf(GL_LIGHT1,GL_CONSTANT_ATTENUATION,0.01);
  glLightf(GL_LIGHT1,GL_LINEAR_ATTENUATION,0.01);
  glLightf(GL_LIGHT1,GL_QUADRATIC_ATTENUATION,0.10);
  glEnable(GL_LIGHT1); 
  glEnable(GL_LIGHTING);

//3个行星
glPushMatrix(); 
  GLfloat ball1_mat_ambient[] = {0.0f, 0.0f, 0.0f, 1.0f}; 
  GLfloat ball1_mat_diffuse[] = {0.0f, 0.0f, 0.0f, 1.0f}; 
  GLfloat ball1_mat_specular[] = {0.0f, 0.8f, 1.0f, 1.0f}; 
  GLfloat ball1_mat_emission[] = {0.0f, 0.8f, 0.0f, 1.0f}; 
  GLfloat ball1_shininess = 500.0f; 

  glMaterialfv(GL_FRONT, GL_AMBIENT, ball1_mat_ambient); 
  glMaterialfv(GL_FRONT, GL_DIFFUSE, ball1_mat_diffuse); 
  glMaterialfv(GL_FRONT, GL_SPECULAR, ball1_mat_specular); 
  glMaterialfv(GL_FRONT, GL_EMISSION, ball1_mat_emission); 
  glMaterialf (GL_FRONT, GL_SHININESS, ball1_shininess); 


glRotatef(day,0.0,0.0,1.0);
glTranslatef(1.0f, 3.0f, 4.0f);
  glutSolidSphere(0.5, 20, 20); 



GLfloat ball2_mat_ambient[] = {0.2f, 0.0f, 0.2f, 1.0f}; 
  GLfloat ball2_mat_diffuse[] = {0.2f, 0.0f, 0.2f, 1.0f}; 
  GLfloat ball2_mat_specular[] = {0.2f, 0.0f, 1.0f, 1.0f}; 
  GLfloat ball2_mat_emission[] = {0.2f, 0.0f, 0.2f, 1.0f}; 
  GLfloat ball2_shininess = 200.0f; 

  glMaterialfv(GL_FRONT, GL_AMBIENT, ball2_mat_ambient); 
  glMaterialfv(GL_FRONT, GL_DIFFUSE, ball2_mat_diffuse); 
  glMaterialfv(GL_FRONT, GL_SPECULAR, ball2_mat_specular); 
  glMaterialfv(GL_FRONT, GL_EMISSION, ball2_mat_emission); 
  glMaterialf (GL_FRONT, GL_SHININESS, ball2_shininess); 


glRotatef(day,0.0,1.0,0.0);
glTranslatef(-1.0f, -1.0f, 2.0f);
glRotatef(year,0.0,1.0,0.0);
  glutSolidSphere(0.5, 20, 20); 



GLfloat ball3_mat_ambient[] = {0.5f, 0.0f, 0.0f, 1.0f}; 
  GLfloat ball3_mat_diffuse[] = {0.5f, 0.0f, 0.0f, 1.0f}; 
  GLfloat ball3_mat_specular[] = {0.5f, 0.0f, 0.0f, 1.0f}; 
  GLfloat ball3_mat_emission[] = {0.5f, 0.0f, 0.0f, 1.0f}; 
  GLfloat ball3_shininess = 1000.0f; 

  glMaterialfv(GL_FRONT, GL_AMBIENT, ball3_mat_ambient); 
  glMaterialfv(GL_FRONT, GL_DIFFUSE, ball3_mat_diffuse); 
  glMaterialfv(GL_FRONT, GL_SPECULAR, ball3_mat_specular); 
  glMaterialfv(GL_FRONT, GL_EMISSION, ball3_mat_emission); 
  glMaterialf (GL_FRONT, GL_SHININESS, ball3_shininess); 

glTranslatef(-5.0f, -5.0f, -2.0f);
glRotatef(month,0.0,1.0,0.0);
  glutSolidSphere(0.5, 20, 20); 
glPopMatrix();glPopMatrix();glPopMatrix();

  glPushMatrix();
//背景图加载，因为希望和第一个行星一起运动：
GLfloat light2_position[] = {2.0f, 5.0f, -2.0f, 1.0f};  
  GLfloat light2_diffuse[] = {1.0f, 1.0f, 1.0f, 1.0f}; 

  glLightfv(GL_LIGHT2, GL_POSITION, light2_position); 
  glLightfv(GL_LIGHT2, GL_DIFFUSE, light2_diffuse); 
 
glLightf(GL_LIGHT2,GL_CONSTANT_ATTENUATION,0.01);
  glLightf(GL_LIGHT2,GL_LINEAR_ATTENUATION,0.01);
  glLightf(GL_LIGHT2,GL_QUADRATIC_ATTENUATION,0.10);
  glEnable(GL_LIGHT2); 
  glEnable(GL_LIGHTING);
  glRotatef(year,0.0,1.0,0.0);
  glBindTexture(GL_TEXTURE_2D, texback); 
  glBegin(GL_QUADS);  
  glNormal3f(0.0f, -1.0f, 0.0f); 
  glTexCoord2f(0.0f, 0.0f); glVertex3f(-8.0f, -8.0f, -2.0f) ; 
  glTexCoord2f(0.0f, 1.0f); glVertex3f(-8.0f, 8.0f, -2.0f) ; 
  glTexCoord2f(1.0f, 1.0f); glVertex3f(8.0f, 8.0f, -2.0f) ; 
  glTexCoord2f(1.0f, 0.0f); glVertex3f(8.0f, -8.0f, -2.0f) ; 
glEnd(); 
  grab() ;
glPopMatrix();

glutSwapBuffers(); 
glFlush();

对于初学者，最好是在一些示例程序上做改动。
http://www.codesampler.com/code/