Using Nvidia Flex to model partially soft objects


I’m struggling with how to use Flex in Unreal Engine 4, and I’d really appreciate some help and guidance. After struggling for a couple of hours, I was finally able to import a mesh, add a Soft Asset, and have it be somewhat deformable (turns out the trick was to change it from a StaticMeshActor to a FlexActor, of all things). Now, I’d like to be able to take something like a cube, and have it be soft and deformable on one side and rigid on the opposite end. Is there anyway to do this sort of thing?

And more generally, is there any nice tutorial out there for using Flex in Unreal Engine 4, and how to write and integrate code to determine the properties of the soft body? This would be very useful for exactly this sort of application, where I could programmatically define properties of my mesh, and make it softer in certain places. Thanks!