I have made this video to show the workflow I am using to convert Unity’s asset to Unreal. This includes using Bitmap 2 Material, generating collision and changing the LOD. The link to the master material I use that is compatible Unity PBR is in the Video description: https://youtu.be/xvJ1zdCU-DM
This tutorial is targeted to the Unity’s users who want to move their projects and assets to UE4. In 10 min I cover the essential.
It can also be useful for the UE4 users who need something that is only in the Asset Store.
Of course always check the license attached to the asset to be sure that you can use the asset to make a game on any platform and any development tool, in case of you want to sell the result.