Two Problems with Lighting

OpenGL OpenGL: Basic Coding
1

I have programmed a textured mountain and I have the following problems :

  1. The triangles get darker and darker as I walk towards them.
  2. When I try to set the light “at infinity” by setting its w-coordinate to 0, I get a blank screen.
    Please help !
2
  1. Have you set the normals (just checking)
  2. Why do you need the lightsource at infinity? Try setting it to a normal coordinate.
3

If you set w=0 then light (x,y,z) means light direction but not position. (0,0,0) will mean no direction.
Default lighting is not bad(its a directional light that points into the screen), so try it.
If screen is blank, you turned ambient light off. What for?

4

If the lighting is changing at all, then you aren’t setting up the light position/direction in the right place. You should do this after you set gluLookAt (or whatever you use for your camera matrix), since light position/direction is transformed through the modelview matrix.

5

I thank very much for your answers !