I import Broadleaf_Mobile.spm from Free_SpeedTree_Samples_for_UE4.zip, but it looks rought. Howerver it looks find in Unity.
Here is the screenshot, any advice would be appreciate.
You haven’t actually uploaded a screenshot.
You probably should flip the green channel. Speedtree stuff never look good in ue4 upon import anyway. Spend your time on tweaking the materials.