If you mean John, then yes, he won’t share it.
It’s pretty easy to hide all blocks that don’t have a visible mesh site. There are TONS of algorithms out in the Internet
to rebuild the Chunk System of Minecraft. Blueprint only is always a bad idea for calculation heavy Projects, but
it can be achieved with good performance using a combination of the “Instanced Static Mesh Component” and the
“Procedural Mesh Component”. First one is used for the 27 chunks surrounding you and the second component is used
for everything further away.
If you then only add instances for visible Blocks (blocks that don’t have a block at all 6 sides) and combine multiple faces
into 1 (on the Procedural Mesh Component), then you can get good performance (: