Hello!
I have an FBX that has a blendshape animation. The blendshape has a few in-between blendshapes. Imported into Unity perfectly. Unreal…not so perfect. The blendshapes have been imported, but the animation ignores the in-betweens.
Based on the animation importing successfully into Unity makes me think I’m not using the correct import settings for Unreal, but I’ve tried reimporting with all sorts of different settings. No luck.
Any ideas?
Here is a video to show the issue: https://youtu.be/natWCBwb0KY
Maybe @Marc_Carlyon can help you with this? 
I cant be totally sure as its somethnig that i havent done myself yet although it will be something i need to do.
Its either not been imported into Unreal correctly (using a TOAs reference pose checked off) which is unlikely but its more likely from what i have been reading into that unreal cant deal with blender having root motions attached to the animation.
These links if they arent entirely helpful may set you on the right track.
Let us know how you get on as its somethnig i need to deal with in the future when i get back to my own project.
Importing to unreal
https://answers.unrealengine.com/questions/24233/how-can-i-get-my-animation-into-ue4-from-blender.html
Root Motion video
Hope it helps
Thanks so much for your response @Marc_Carlyon!
Unfortunately, I don’t think this is related to root motion. I set up a test last night with all blendshapes animated individually, rather than in-betweens, and it worked in Unreal.
After researching and doing import/export tests all weekend, I’ve come to the conclusion that Unreal just does not support Maya’s blendshape in-betweens. Found some forum posts about Unreal not supporting 3ds Max progressive morphs, which sounds like the same thing.
It’s certainly not the end of the world, just less convenient. It involves a bit more work to animate each individual blendshape vs having one overall blendshape slider. An overall blendshape slider can be created with driven keys (in Maya at least, not sure about other software), but again it’s additional work to setup.
I’m out of time to research this any further at this time but I will very likely try to find a workaround for this in the future…because it’ll bother me lol.
Thanks for posting back as well! Its something that will sure to bug me as well when i change over from the standard animation placeholders i have in my project to my own characters.
What threw me i am not familar with 3ds max so blender might not have that feature but if it does then i will have to watch out for it too!
Please post back if you do ever find a workaround as its always good to learn 
Sorry my suggestions didnt help much,