Maps with Opacity Filter and transparency :
1. Create New Map Standard
2. Pick up Diffuse Texture map.
3. Put the bump texture map.
4. Choose the opacity texture map.
5. Assign texture to Object
6. Generate UVW Box Map.
7. Donner des proportions réalistes à la boîte de coordonnées / Give the best length-height-width to your map.
8. Render Scene (F9).
9. Does it match ?
10. Another example with one opacity map.
11. Another simple example with multiple opacity maps.
Tuto by JiM's