The primary intension of reflectivity maps is to define the reflectivity of the material. But (if your rendering software supports this) you may also use this map in several more ways, e.g. Refl. map controling blur radius
as reflection blur map
as IOR map
as specular/glossiness map
as roughness´map
...
Keep in mind that you may have to modify the map to achieve realistic results (see also the next tip).
The primary intension of reflectivity maps is to define the reflectivity of the material. But (if your rendering software supports this) you may also use this map in several more ways, e.g.
Refl. map controling blur radius
Keep in mind that you may have to modify the map to achieve realistic results (see also the next tip).