Multiblocks!

[Ommina]

OK.  In 1.14.4.  I have a block model that is 3x3 actual blocks in size.  It will place in the world just fine, and I can change the "this is the block you are targeting" outline through getShape.  Unsurprisingly, though, only the centre block actually exists as far as the game in concerned.  Entities can walk though, and blocks can be placed in, the remaining 26 spaces.

 

I know this has been done many times by many people in the past, so I'd like to turn to the wisdom of others before trying my own solution.

 

As I see it, there's a couple of options.

 

1) Keep it as one block, but fill in the missing blocks with transparent filler blocks on placement.  I like this one, but I don't see a really convenient way to indicate to the player that "this block needs a 3x3 space to place.  Oh, and make sure there are no entities in that space either".

2) Go the more traditional controller+extra blocks that are placed individually, that vanish and turn into the model when the last block is placed, presumably by the central controller block continually scanning the other 26.

 

In this case, I do not have any capabilities attached to the block.  (But it DOES have to respond to redstone).  But I'd be interested in hearing how either approach (or any other) works better for capabilities.

 

So, my question.  What's a good way forward here?  Are there other options that I have not considered?  Which is least likely to come back and bite me later?