Exposing a Type within the Engine to Blueprints

Hello Everybody,

Essentially what I want to do is convert the class FBoxCenterAndExtent which is defined in GenericOctree.h into a struct and expose that struct to blueprints. I understand how to expose structs using USTRUCT() in my own projects, but I am not sure of how to expose a type in the engine source. For instance the struct FBoxSphereBoundsis exposed to blueprints, but it doesn’t use USTRUCT().

So my question is, how do you expose engine variables to the Blueprints system?

Any help is appreciated,