Block Sculpture
The Sculpture Block is a block for representing all the sculpted blocks in this mod.
The block is not opaque, with change-able bounding box and collision boxes, depending on the sculpture shape.
Each Sculpture Block in the world holds a 64-byte array representing the shape of the sculpture, and id/meta representing the block that this Sculpture is sculpted from.
The sculpture block is not accessible by the player. It is created in the process of sculpting.
The sculpture block has a gl display list which is updated when either the shape changes, or the brightness of the block changes. Ordinary render updates only compiles the existing gl display list into Minecraft's display list, but doesn't update it.