Importing Ready Models from 3DMAX to Unity, Materials

I was wondering if there's a way to import the 3Dmax models into Unity along with the materials keeping the high quality. I use models either downloaded or bought from online sources with their own materials. When I import them into Unity, the materials lose quality or don't appear. "Example: glass material isn't transparent anymore". Do I have to modify the materials in Unity each time, or have my own Unity material library? Is there a way to keep the 3Dmax materials as they are without modification?

The same question applied on materials for different 3Dmax renderers: V-Ray, Mental ray ...etc.

Please provide tutorials and examples if you know any.

Greatly appreciated.

some 3d max materials use special shaders. unity don't support those shaders so they don't appear. unity creates materials based on the texture and material properties but those FX code in shaders of max are not supported in unity so you should choose a shader like that in unity or write one if you can. unity sometimes loses the connection between the material and it's texture or material and it's model after import and you should connect them yourself.