Generating Normal Maps

Normal maps can turn boring smooth shaded models into detailed and realistic looking ones. Generating normal maps are as easy. You just need a normal map generator( or write on yourself). here is tools:

NDO

This is a powerful photoshop plugin for creating normal maps. This was free then became a commercial project. The free one can be found here, but i think the commercial project was taken down. The author’s website is here and a tutorial is here.

NormalMapper

This application find the dfference between hi-res and low-res models and output the difference in normal maps. Link here.

NormalMapper(AMD)

AMD seems to have a normal map generator with the same name. It’s not in development anymore, but its still available for download.
link

SSBump Generator

This is a free tool for making self shadowed bump maps for valve’s source game engine
link

Normal Map Generator

Another free tool for making normal maps. Made by the same person who made the SSBump Generator. This one makes it easier to batch normal map coversions
download page

ShaderMap

This is a commercial software. It makes professional looking nomal, displacement, specular and ambient occlusion maps. You can visualize your normal maps on models in it as well. It also comes with an SDK for some reason :/. You can download the demo for free.
download page

xNormal

another software for baking normals from hi-res models to low-res ones in to normal maps
link
download page

MindTex

Commercial, but you can try it free for thirty days
link

CrazyBump

This is a popular one, and my personal favorite . It’s commercial, but comes with a 30 day trial but for its beta version. It generates normal, displacement, specular and AO maps like ShaderMap.

Gimp Normal Map Plugin

This one has free written all over it. You can generate normal maps right after drawing them and preview them on models. link

Resource:  http://nickthecoder.wordpress.com/2012/08/23/generating-normal-maps/