Virtual/Custom Item frames crafting

WARNING:This will not work with Minecraft 1.7.4 or lower,it was made in the 14w02c snapshot and might not work in future versions.

So you should already know what this is,it's basically a fancy crafting "table" with custom recipes in it by using item frames and the new commands in the 1.8 snapshot.Let's begin!

First thing we need to do is summon the item frames,you will need a 3x3x1 cuboid to start,then place blocks around it to prevent the item frames from glitching out and falling.

Now you'll need to summon the item frames by using these commands,so here's how it works: Firstly it uses /summon ItemFrame x y z {TileX:?,TileY:?,TileZ:?,Direction:0,1,2 or 3}
It might be confusing for some of you,/summon is a command use for summoning entities (item frames are entities not blocks) x y z are the normal x y and z co-ordinates,where the item frame actually IS,it is basically,which block the item frame ITSELF is IN,NOT the block it is ON.Next the NBT tags, TileX Y and Z are NOT the same as the co-ords they are the co-ords for the block the item frame is ON. example:I placed an item frame on a sand stone block,the tile co-ords will be the same as the sand stone's while the normal co-ords will be one block to the SIDE of the sand stone's. Finally direction.You basically have to choose between 0 1 2 or 3 which is South West North or East in order I believe.You need 9 commands in 9 command blocks to summon 9 item frames on the 9 blocks.

The next part is the main body,it will consists of how to detect certain recipes once placed into the crafting grid and what it will do is pretty simple,once it detects that recipe it will remove the item frames,give you the item and finally,it will reset the crafting grid by doing the following:

First important part of this design is the redstone clock,it uses a comparator clock,some people don't know how this works so let me explain.A comparator has two modes,comparison mode and extraction mode as I call it.The first one is pretty simple,if the signal going into it's side is stronger than the signal going into it's input(back) it will not give an output.In the second mode,it will compare the input signal with the side signal.Output = Input - Side. Since there's a block in front of this comparator,the first piece of redstone on the top right corner has a signal strength of 15,while the other one,one block below it has a signal strength of 14. 15-14 = 1,this creates a loop.Since the top-right piece of redstone now has a signal strength of one,there is no power at the redstone going into the side of the comparator.This makes it so that the top-right piece of redstone is STILL being powered while the other one is not,however the lever is still on making the signal strength of the comparator 15 again,and it loops around.My point is that the top-right piece of redstone will always be on while the bottom one on the side of the comparator will toggle,many master redstoners didn't understand this concept at first,this is actually important,if you connect a line of redstone to the top-right piece,it will always stay on as long as the lever is on,however the one to the side of the comparator will toggle once the lever is on.
Now here is how you detect and code your very own crafting recipes.This uses /testfor @e[type=ItemFrame] {TileX:?,TileY:?,TileZ:?,Item:{id:?}} /testfor is a command use for testing if an entity is in the current world,but we only wanted to detect item frames,that's why we specified the type of the entity(pretty obvious) If you remembered,Tile X Y and Z are the co-ords of the block the item frame is on,make sure you match each of them up with the slot you want.Finally the Item tag,you will need to tell it what item you want in that specific slot using item IDs,which you can view by pressing F3 and H at the same time and mousing over an item,note that these command blocks are being powered by the comparator clock.This seems pretty easy now....However...

I am making this custom crafting recipe for a chain chest plate,everything is fine until I realized I needed a way to test for empty slots like for example,the one in the top-middle of the grid.Also I needed a way to combine the results of all the command blocks and use the data.

That's where this comes in.First I use comparators to receive inputs from the other eight command blocks to see if they detect that certain item in that certain item frames,if yes then the comparator will turn on,deactivating these redstone torches,going into another redstone torch making a gate.I needed to reverse the results of the empty grid by simply testing if there was an item in the grid,if so then the signal will stay on keeping the last torch unlit.

Once all of that is over,it's time for the final piece of the puzzle,these last few command blocks will reset the crafting grid and give you the item you wanted.

This command is so simple,it's basically a command that gives everyone a chain chest plate,you can however change this to @p,making it so that only one person gets the plate OR you can do something a little bit advance,you can spawn an item entity using /summon Item x y z {Item:{id:?}} so it's a little bit more fancy.Go wild,maybe spawn an item frame with something in it if you want to.

This next command is a /kill command that only kill the item frames near the crafting grid area,make sure you get the x y z and radius right else,you'll destroy lots of frames.

Finally,after killing the item frames we can finish the process by spawning new ones in,remember the nine command blocks at the start? These two command blocks will place a redstone block.....

Over HERE(The picture down there) Then quickly replace the redstone block with air.This will activate the nine blocks and replace all the item frames.

Now let's have these two pics show the machine in process.I basically place the final iron ingot and took two screenshots in a role.


As you can see,I now have another chain-mail chest plate in my hot bar.

That concludes my EXTREMELY LONG AND LARGE tutorial on how to make itemframes-based crafting grids and custom recipes with it.Remember though,it's not survival,although it's vanilla.It's not that easy and it's not that hard.It's just a concept. A MINECRAFT MAP CONCEPT.