   newbie lighting question
  I have some problems with OpenGLs standard lighting: I have a 3d-model, when I look at it from above it's much darker than if I look at it from beneath it. The lighting changes when I look up/down (without moving my position, just changing my viewing direction). afaik direction shouldn't affect the lighting, it's not any specular highlighting, at least I don't want any.This is how I set up my lighting.  lightPosition[] = {100.0f, 500.0f, 10.0f, 0.0f};  lightDiffuse[] = {0.8f, 0.8f, 0.8f, 1.0f};  lightAmbient[] = {0.5f, 0.5f, 0.5f, 1.0f};  glEnable(GL_TEXTURE_2D);  glEnable(GL_LIGHTING);  glEnable(GL_LIGHT0);  glEnable(GL_COLOR_MATERIAL);  glColorMaterial(GL_FRONT, GL_DIFFUSE);  glLightfv(GL_LIGHT0, GL_POSITION, lightPosition);  glLightfv(GL_LIGHT0, GL_DIFFUSE,  lightDiffuse);  glLightfv(GL_LIGHT0, GL_AMBIENT,  lightAmbient);    glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
  The reason that you are getting this problem is that your light source is in the same place even if you are displacing the camera to look at the top or the bottom.The diffuse lighting is like specular, it depends on the position of the light source...If you change the camera position to view it from a diffrent angle, you must also change the light position to compensate.In one instance (the top), you are only seeing the ambient light because the diffuse light is being blocked by the model.In the other (the bottom), you are getting the ambient light and the diffuse light so it looks brighter.To test this, you can set your ambient light to blue (0.0f, 0.0f, 1.0f), and your diffuse light to green (0.0f, 1.0f, 0.0f).If I am correct, the bottom of the model will be yellowish, while the top will be blueish...Hope this helps.   ;  ah, yes, thanks!I changed so my light source is placed after the call to the camera's lookAt-method, and now it works.   