Under suggestion I post this here.
Unity’s shader are comprehensive but sometimes they lack elasticity, and in ways that I can’t understand…
In this case, the shader TRANSPARENT/BUMPED SPECULAR is chained perversely: it unifies the TRANSPARENCY texture and the GLOSS texture in the same alpha channel of the main texture, taking off A LOT of control over the shader.
This means that you cannot make a bottle in the way you want with a single shader.
Imagine in example a glass bottle with a cork cap: the cork cap, which is of course not transparent at all, will shine like if it was metal and there’s nothing you can do about it.
Actually, the only solution is another shader: so, at least 2 drawcalls.
I’m just asking this little favour (it should be something really quick to do): can somebody practic with shaders change this shader and make it take ALPHA CHANNEL FROM NORMAL MAPS as gloss information, instead than using the one from the diffuse texture?
Of course this will not be my private stuff: it will go on the Unity Wiki so it’s a favour that will probably help all Unity users.
Thank you! 
