Tutorial demonstrating how to draw a tangent space normal map for an existing texture map.
http://shadermaptutorials.com/tutorial/drawing-a-normal-map-for-a-texture/
This tutorial shows how to use a combination of Normal Editor and Map Generation skills to draw a custom normal map for an existing texture map. Before starting you should ensure that you have at least ShaderMap version 3.0.3 installed. In this example we will be drawing a normal map for an analog pressure gauge.
Here are some images from the tutrorial:
View additional ShaderMap Tutorials at the home page: http://shadermaptutorials.com/
Thanks for looking