Call a C++ function through blueprints? / Update Mesh Distance Fields with origin shifting

On creation it is has given me warning here:

“Successfully added class ‘BlueprintFunctions’, however you must recompile the ‘LandNav’ module before it will appear in the Content Browser. Failed to automatically compile the ‘LandNav’ module.”

Not sure if that is important right now or not but I was a little unsure if I should leave this new class in its default directory which was not in the content directory but in the source.