There are several ways to produce normal maps.
The easiest way is just to provide the same texture as the diffuse one and render a normal map out of this. There are several free tools around for this or unity for instance does this automatically by tagging a texture like this. You can also alter the horizontal displacement there. So it's really easy and useful for a lot of stuff. Obviously you could also use textures like slight scratches or stuff like that on any surface where it fits.
The harder way for most poeple would probably be to render out the normal map out of a high and a low poly object. Also free tools available if your 3d app isn't able to.
In the end normal mapping is adding detail really easily in a lot of cases. You get the best results when the light is moving relativ to the object or if you/light look at the object at a proper angle.
There do exist several more advanced mapping techniques which try to eliminate the downsides of normal/parallax mapping like relief mapping and others but they are quite performance eater and/or do require ps3 support.
The easiest way is just to provide the same texture as the diffuse one and render a normal map out of this. There are several free tools around for this or unity for instance does this automatically by tagging a texture like this. You can also alter the horizontal displacement there. So it's really easy and useful for a lot of stuff. Obviously you could also use textures like slight scratches or stuff like that on any surface where it fits.
The harder way for most poeple would probably be to render out the normal map out of a high and a low poly object. Also free tools available if your 3d app isn't able to.
In the end normal mapping is adding detail really easily in a lot of cases. You get the best results when the light is moving relativ to the object or if you/light look at the object at a proper angle.
There do exist several more advanced mapping techniques which try to eliminate the downsides of normal/parallax mapping like relief mapping and others but they are quite performance eater and/or do require ps3 support.