Opacity/Placement

Many transparent blocks exhibit unique behavior when it comes to being placed or being placed on. This page covers only those blocks that exhibit unique behavior. For example, glass is not covered as everything can be placed on it. In addition, only blocks that need some sort of support are covered in the columns.
==Placement on top of blocks==
 	Amethyst Cluster	 				 	 	Coral	Coral Fan		 		KelpNeed water first. 	Lantern		Need to have a light level ≤ 12 first. 			Rail						Seagrass				Torch			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		This block breaks when water flow into it. 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		Cactus does not break when water flows against the side, but breaks when water flows on top.	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
(up=true) 	 	 				This can cause the chorus plant to update.	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
(with eye) 	 	 				 	 	 	 		 		 	 		 			 						 				 			
(without eye)	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		End rod emit a light level of 14, more than the maximum light level that mushrooms can place on blocks that not podzol, mycelium, and nylium.			 						 				 			
 	 	Block is converted to dirt.				 	Block is not converted to dirt when placed on top.	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		Works only on Overworld wood fences. 		 	 		 			 						 				 			
 	 	 				 	 	 	 		Works only on Overworld wood fence gates.		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
 	 	 				 	 	 	 		Works only on Overworld wood fence gates.		 	 		 			 						 				 			
 	 	 				 	 	 	 		 		 	 		 			 						 				 			
Everything can support:
* 
* 
* 
Everything can be placed on:
* 
* (top, closed)
* 
* 
* 
* 
== Placement on the side of blocks==
										Amethyst Cluster	Coral Fan						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
										 	 						
Everything can be placed on the side of:
* 
* 
* 
* 
* 
* 
* 
* (top or bottom, open)
* 
* 
* 
Everything cannot be placed on the side of:
* 
* 
* 
* 
* 
* 
==Placement on bottom of blocks==
 	Amethyst Cluster	 			 	 				 	In Bedrock Edition vines cannot be placed under blocks at all.		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
Chests 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	Only if the grindstone is facing down.			Only if the grindstone is facing down.	Only if the grindstone is facing down.				Only if the grindstone is facing down.	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	Only if the funnel is facing down. 			Only if the funnel is facing down. 	Only if the funnel is facing down. 				Only if the funnel is facing down. 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
Only if the trapdoor is the bottom half and closed.	 	 			 	 				 	 		
 	 	 			 	 				 	 		
 	 	 			 	 				 	 		
Everything can be placed under:
* 
* 
* 
* 
* 
* 
* 
* 
* 
* (the chorus flower breaks)
Everything cannot be placed under: 
*
*
*
*
*
*
==Doors and trapdoors==
Doors and trapdoors behave in unique ways. The flat side of each block acts as a solid surface, allowing anything to be placed on it. However, all other sides act as non-solid blocks. Because of this, many blocks that can be placed on doors and trapdoors do not stay in place if the door or trapdoor is opened or closed.
Signs and banners can be placed anywhere on a door or a trapdoor and cannot be destroyed unless the door or trapdoor itself is destroyed. Cakes and sea pickles can be placed on the tops of doors and trapdoors and are not destroyed when the door or trapdoor opens and closes. Rails, redstone dust, redstone repeaters, and redstone comparators can be placed only on a closed trapdoor in the top half of a block, but are not destroyed if the trapdoor is opened until the block is updated. All other blocks are destroyed when the door or trapdoor changes states.
==Shulker boxes==
Shulker boxes typically act as a solid block in that they allow everything to be placed on them. However, many of these blocks are destroyed when the shulker box is opened. This behavior is also dependent on the rotation of the shulker box.
===Upward-facing shulker boxes===
Upward-facing shulker boxes do not destroy most transparent blocks placed on their tops or bottoms when opened. However, some blocks stop the opening of the box.
*
*
* (top only)
*
*
* (top only)
*
*
While most blocks placed on top of upward-facing shulker boxes, the same is not true for blocks placed on the sides. Signs are not destroyed, but the following blocks are.
*
*
*
*
*
*
*
===Sideways-facing shulker boxes===
The following blocks stop a sideways shulker box from opening when placed on their front
*
*
Sideways facing shulker boxes destroy the following blocks when opened.
* (top, side, and bottom only)
* (top, side, and bottom only)
* 
* (side only)
*
* (side only)
* (side and bottom only)
* (top, side, and bottom only)
*
* (side only)
===Downward-facing shulker boxes===
The following blocks stop downward-facing shulker boxes from opening. 
* (bottom only)
* (bottom only)
Downward-facing shulker boxes do not destroy any blocks placed on their tops or bottoms when opened. However, they do destroy some when placed on the sides.
*
*
*
*
*
*
*
==Pistons==
All transparent blocks can be placed on unextended pistons. However, on Java, many blocks cannot be placed on extended pistons and/or are destroyed when pistons extend or retract.
===Upward-facing pistons===
All blocks (except for vines) can be placed on the top or bottom of an extended upward-facing pistons. Only signs and banners can be placed on the sides of extended upward-facing pistons. However, they destroy most blocks when extending or retracting.
Blocks destroyed on extentionIf the block can be placed on an extended piston, it breaks upon retraction.	Blocks destroyed on retraction	Blocks that stop extentionIf the block is placed on the extended piston, it is destroyed on retraction.	Blocks not destroyed
* (top, side)
* (top, side)
*
*
*
*
* 
* (top)
*
*
*
* (top, side)
*
*
*
* 	
* (normal pistons only)
* (bottom)
* (bottom)
* (bottom)
* (bottom)	
* (top)
* (top) 	
* (side)
* (side)
* (sticky pistons only)
===Sideways-facing pistons===
The following blocks can be placed on extended sideways pistons.
*
*
* (top, head, and back of piston only)
* 
*
* (head and back of piston only)
* (head and back of piston only)
* (head and back of piston only)
* (head and back of piston only)
* (head and back of piston only)
*
*
* (head and back of piston only)
Blocks destroyed on extention	Blocks destroyed on retraction	Blocks that stop extention	Blocks not destroyed
* (top, side, head, bottom)
* (top, side, head, bottom)
*
*
*
*
*
* 
* (side, head)
* (side, head)
* (side, head, bottom)
* (top, side, head, bottom)
*
* (side, head)	
*
* (top, back)
* 
* (back)
* (back)
* (back)
* (back)
* (back)
*
* (back)	
* (head)
*
 (head) 	
* (top, side, back)
* (top, side, back)
*
===Downward-facing pistons ===
All blocks (except vines) can be placed on the top and bottom of extended downward facing pistons. The only blocks that can be placed on the sides of extended downward facing pistons are signs.
Blocks destroyed on extention	Blocks destroyed on retraction	Blocks not destroyed
*
* (side, bottom)
* (side, bottom)
*
 (side)
*
* (side, bottom)
* (bottom)
*	
* (top)
* (top)
*
*
*
*
* (top)
*
* (top)
*
*
* (top)
*	
*
*
*
*
==References==
zh:不透明度/放置
Category:Environment