+
+items
+
+ items representing both blocks and non-blocks (such as tools, weapons,
+ armor), with a simpler physics simulation than entities, much like the
+ one for particles
+ they can be picked up by entities, so those should have one or more parts
+ in their skeleton to render them when they're "held"
+ players' inventories have to be changed so they select an item rather
+ than a block
+ item IDs could be the block ID for blocks, and anything from 2^16 up for
+ non-blocks