3D UI plugins?

Looking to create some 3D based UI, and was wondering if anyone had any recommendations for pre-existing plugins or systems to use?

Not for a VR project, but would be handy if it supported that as well. Need gamepad and keyboard based input support.

UMG (the built-in, blue-printable animated UI builder in Unreal Editor) supports being placed in 3D (in the world) using the WidgetComponent.
It’s not clear what a “plugin” would help with – do you have some more specific details?