The flying item that moves across the screen when a block is quick moved should look identical to the block icon when placed in a slot, however for custom blocks the flying item does not use its backface culling configuration, instead always enabling backface culling.
Steps to reproduce:
Install and apply the provided behaviour pack which adds a custom block to the "Construction" tab in the creative menu.
Give yourself the custom block and move it around the inventory by holding down Shift and clicking on the item.
Observed results:
The displayed flying item has incorrect rendering.
Expected results:
The flying item should look identical to the regular block item.
Shading and opacity is now fixed but back faces are still being culled when they shouldn’t be.