Hi Belidos,
this what i've got from Pirate myke.
The more metal you want it, the whiter the spec has to be. I usually clamp it with levels. Bring up the white and then bring the black down to cut the darker areas, then find a happy medium, with the mids.
I also combine a gloss and a specular map together. a PBR work flow.
Try this: hopefully a bit the same in Gimp, because i use photshop
Open the diffuse texture, Then under it set the normal texture. Duplicate the diffused and drag it below the normal map. this will be your specular map.
Hide the top diffuse and the normal layer.
Select the bottom to be specular layer.
Desaturate it. Leave it for now.
Hide that layer, and unhide the normal layer.
Desaturate it, and invert it. Set the layer to be screen blend. Clamp it with levels to just show the edges white.
unhide the to be specular layer again.
In the normal layer turn on screen blend mode.
Bring the transparency down till the spec and the clamp normal have a good blend.
Merge those 2 layers.
Turn on the top diffuse map.
Desaturate it and adjust the levels concentrating on the metal part and bring it lower the the bottom one.
Get a nice grunge brush and turn the foreground color white. Transparency to 15 so you can build this up.
Paint on the top layer diffuse, and add in areas of light and dark to represent scratches and dirt build up. Keep the real world in mind here. This will represent the gloss or surface roughness of the material. Black is rough and white is mirror.
When done with that. Drag the top layer under the bottom layer.
Use overlay and transparency to blend them together for the perfect spec map for Game Guru.
hopefully it is useful for you.
Harry
Harry
When nothing goes right, go left