Custom Texturing

I have been further learning the Radiant/Doom 3 Editor and have learned a lot about texturing. There are separate channels that the texture must be split up into: specular, normal map (bump), and diffuse. Diffuse= main color information and overall look of object; specular= highlights- a desaturated version of the diffuse with enhanced value gradation; normal map= grayscale version that is used to simulate a height map on a flat surface. An easy way to convert your diffuse maps into a normal map is the NVIDIA Normal map filter: a plugin that can be downloaded from http://developer.nvidia.com/object/photoshop_dds_plugins.html. All three of these separate channels are combined using a material file that tells each how to react to light. This is the magic of texturing! The texture cannot be viewed in its full effect until compiled in game. Texturing is tough business but pays off... in the words of 3D World Magazine: "texturing is 99 percent of the visual experience of a game."