HELP: My character's outer eyeballs loses transparency in Unreal Engine/ Mudbox ...

I’ve attached screenshots including UV maps to visually explain. For my character’s eyeball, I have two spheres (the main eyeball and the outer transparent/specular sphere).

Eyeballs look fine in Maya because I have transparency and specular set up in material attributes. When I import my model into Mudbox or Unreal Engine for example, the outer sphere loses transparency . I’m not sure if the specular stays or not. Maybe it does?

How do I get both (transparency / specular shine) to stay when I import into Mudbox or especially a game engine? Do I have to make a separate specular texture map or something? How do I achieve this so outer spheres aren’t a solid grey?

It’s best to have the eyes as a separate material–to do transparency you have to set that up in the material and in a game engine particularly that will change the material type and you don’t want the entire character material to be a transparent material.