Lots of info here http://wiki.polycount.com/wiki/Modular_environments NDO is very easy to pick up and play with. Some good videos here. http://wiki.polycount.com/wiki/NDO Sometimes it's better/faster to model high-poly models and bake them. http://www.philipk.net/tutorials/materials/metalmatte/metalmatte.html…
Those three panels look like he's adjusted the vertex normals, instead of using a normal map. Here's the method: http://wiki.polycount.com/wiki/VertexNormal#Smoother_Shading