This tutorial is under Gnu Free Documentation license
Parralax map with gimp FR
Parallax texturing is an improvement of the bump/normal mapping you can read more about it on wikipedia
we will show you how to create a parallax mapping on GIMP
you will need normal map pluging for gimp you can get it here
in our exemple we will work on a paved road i found on flickr
once you have installed the normal map plugins , open the image you want to map with GIMP
you must copy the layer of your pic then you will work on the copy and adh an alpha channel to you layer (this is mandatory for the normalmap plugins to work correctly on this case)
go on the Color menu and click on desaturate , you calc should now be just black and white
Return in the color menu and click on invert
when your pic look like the pictures above you can work on it and modify it to achieve the result you want , but for our exemple we will keep it this way it will do the job to illustrate the idea.
Go on Filters menu -> Map -> normalmap (you must have installed the normalmap plugins correctly).
In the normalmap plugins menu clik on 3d preview
in the 3d preview window choose you original layer as diffuse map (the color map)
in the plugins menu set the alpha at height , leave the height source at average RGB because we haven't worked on the alpha menu on this case if you do so , you must choose the *alpha* as height source (i'm just not good enough at GIMP to do this kind of stuff)
at this stade you almost done the bases , but you will see nothing until you set parallax or parallax occlusion in the bump mapping on the 3D preview window
as you can see our result is not perfect but you get the point , if you play with the wit the normalmap menu the 3D preview will show you the result in realtime , you will also have to modify your layer/alpha channel to achieve your final result , when done just save your layer as file and we will see how to use it in blender later (when i figure how)
