So after working on this on and off for many months now I have some some promising results. I have tried to emulate the default Unreal Engine Mannequin Skeleton to keep some consistency across the assets I am making. I created a deform skeleton and a control rig inside Blender, containing one squash and stretch bone in the torso. This was the result I was getting:
After reading more threads I saw Lina Halper mention a preserve local transform option in the import dialogue. I gave that a go and my result was this:
Notice the arms aren’t being broken by transforms inherited up the bone chain. I was over the moon when I imported this anim. But it was short lived as I found more issues, particularly when if I rotate the bone that sits above the squash and stretch bone. Results pictured here:
(If you have seen the new IT movie it starts to look like the spooky Woman with the Flute.)
This was a bummer. Unfortunately the skeleton also starts to experience problems if you have a squash and stretch chain, on an arm for example. I tested this with the Rigify Rig by stretching the arms. The hands began inheriting unwanted transforms again.
In any case I am still determined to get this to work. I have been messaging one of the Tech Animators at Epic to see if there is anything they can figure. I have thought to contact Lina too because she is the source of all animation knowledge haha, but I figure the folks at Epic are busy people so I will keep chipping away. Hopefully someone will be able to give me a hand either here, or if anyone wants to contact me my twitter handle is @SamBattz](https://twitter.com/SamBattz).
I have posted this update on other forums, thinking of starting a new thread with more clarity in the title.
Thanks for reading 