I am puzzled with OpenGL GLSL recently on using color or material in OpenGL Programming. The problem is : which should be used vertex color or vertex materials, or both?
Previously, I use the color for each vertex. However, it seems that by using material properties we could get a more realistic rendering for viewing. And I realized some good reanding result by using material in my program. However, when I was reading the red book (Programming Guide), I noticed that the book is using both color and material property for rendering when consider multi-lights and multi-materials. I am wondering which is best/correct way to use? Since I have the material property why I need the color for each vertex? Or it is just an example to show that the current GLSL language is so powerful to realize whatever you want by programming ?