Importing Between Rhino, Revit, SketchUp etc.
I have done several program to program conversions, from SketchUp to 3ds Max, to Rhino to Revit and as missing material is only one issue, I suggest error checking in addition to the export options to make these as painless as possible. These programs all have one thing in common perfection with their own format– including Revit’s strict backward incompatibility. The solution is to keep focused in your program to program working.
Here is a method to preserve material, and other elements. For instance, try exporting one object and one material successfully This will inform you best way to export and potential issues. Also, I would not leave anything to chance, test every import.
You can communicate between programs, but a small bit of focus can assure success throughout.