I’ve got this scene in 3dsmax, I can import it into unreal fairly well.
Unfortunatly it doesn’t import the opacity texture from a standard material.
But the real issue is that all the imported materials are specular. Unfortunatly It has over a 1000 materials.
Is their a method to add paramater to my specular and roughness and apply it to all materials in one go?
As far as I know there is no good way how you can do that
-You could create a master material with parameters -> then create a material instance constant and assign them to the meshes. Now when you change that parameter it will change it for all meshes
-create a material parameter collection - in all your materials you have to add the material param collection node and connect it with the specular (+ choose the right parameter) -> now when you change the material parameter collection, it will change the settings for all materials 
So either try the upper suggestions or just open every single material and change the settings
Thanks for the tip, but doesn’t that require you to connect that parameter collection to every specular and roughness in every material?
That’s the problem -> you have to do that for every material, but afterwards you can change all materials with just one parameter