Glad I could help, I was figuring it out myself as well as I was helping.
It pulls off some nice effects as shown in your example. As well the Formula used can be changed to help other isometric games. Think of it as Rotating the X and Y grid lines around the origin.
Well not just layering, I was also converting vectors so I could mark coordinates on a skewed grid plane as if I were on a normal grid plane. The X and Y are translated respectively.
I just used sprites that lined up so I didn’t need to do that (I did mess up slightly so I’ll have to redo a bit). But for smaller 32x32 sprites that lining up is needed.
I’m not really saying it’s just for lining them up… but more so to give the blocks an ID.
For like indicating when the mouse is over the top of the block, moving objects to a skew location, or to see if an object is on its same skewed X axis.
Organization
I just bundled most of the code and added notes that I think would help if you were exporting the code to your game.
Let me know what you think. The last thing I might do is going to be changing the game-view size so I don’t have to spawn as many objects and run so many expressions.