The best workflow I’ve found is to export your model from Revit as .FBX, import the FBX into 3DS Max, convert your units to centimeters, select all the objects and us a script to convert all your materials to standard materials. While all the objects you wish to export are selected, change all the pivot points of the selected objects to a desired by using the align tool. Unwrap the objects with SteamRoller then export the objects in your scene with TS_Tools UE4 FBX exporter. It may be wise to rename some of the objects before exporting them with TS_Tools. This is the workflow I have been using and it works just fine for me. I hope this helps.