   Why do ambient and specular materials have a 4th component?
  Hi friends!One question, I understand that the 4th of diffuse material is the alpha value  (opacity or transparency) but what do opengl need a 4th component on ambient or specular material (or lights) component?Thanks a lot.   
  I suspect the answer is they're colors and colors have 4 components in OpenGL.  Another answer is, why not?  Maybe there are some fun tricks you can do with the 4th component.  Remember, not everyone wants to do default rendering.   ;  Why should there be a difference between diffuse and ambient/specular. In the end it boils down how you calculate your final fragment color. If you are using the fixed function then you can look in the OpenGL docs to see how it is done.Hope this helps.   ;Quote:Original post by CableGuyWhy should there be a difference between diffuse and ambient/specular. In the end it boils down how you calculate your final fragment color. If you are using the fixed function then you can look in the OpenGL docs to see how it is done.Hope this helps.I meant, What is the meaning of alpha component of specular and or ambient colors?Thanks!   ;Quote:Original post by riruiloI meant, What is the meaning of alpha component of specular and or ambient colors?Thanks!basically nothing as long as your using the fixed function pipeline