To be able to select a 3d bock area in the world using something in my hand without adding a new item.
My intent is to be able to save an area to a file on disk including all IDs, registered names, NBT data, and possibly all non-player entities.
Then be able to paste that back into the world.
A extended intent is to be able to bring these saved areas into a newer version of minecraft such as 1.7.2 or 1.7.10 and proceed to interactivly help the user resolve the proper block/item/entity substitutions when pasting. In english: save our buildings etc from old active servers and bring them back into new servers. Well, thats the goal and I am taking this on now.
So for now I am starting with how to setup a selection tool that is easy to use and doesnt add IDs.
I am now looking into using Forge Hooks to do this part.