I am a returning player, who hadn't played since pretty much the beta. After starting up a new survival world, I was surprised to find that my favorite redstone trick no longer works.
After testing different versions, I figured this behaviour changed upon Release 1.8.0, but still couldn't find any documentation on this change. This is a simple trick, but apparently an obscure one: I never heard of anything about it online, nor anything about its underlying mechanics; so I don't know whether this has a name, or whether people were even aware this existed.
My questions are :
Was it a requested or intended change ?
Do the new mechanics have better uses? Would the old mechanic mess with your creations of today ?
The basics - what changed:
You have a door directly connected to a redstone torch and a pressure plate, placing the torch has caused the door to open.
You manually close the door, then step onto the pressure plate: what happens ?
- If you run this on the current version of minecraft: nothing happens.
It's like the torch is short-circuiting the door, preventing the door from reacting to any other redstone stimulis.
This I think is sad.
- If you run the Release 1.7.10 or earlier : the doors reopens.
More interestingly, if you close the door, then step off the pressure plate, the door will also reopen !
This gives you a door that can be opened with a redstone signal, but also opens when removing the signal.
This I like.
The setup - example of usage :
This is a setup I used to place at the entrance of every single of my buildings in survival.
One subtelty of the setup that cannot be conveyed in picture, is that this door was placed sideway, meaning that when the door appears closed, its internal state is actually open, and vice versa. In other words, this reverses the way the door reacts to redstone signals.
Combined with the mechanics above, this door would automatically close whenever something changes the pressure-plates nearby, but it can only be opened manually.
I found this door to be incredibly comfortable to use because :
- Accidentally stepping onto the pressure plate won't let the monsters in.
- You don't have to worry about closing the door behind you.
- If somehow you managed to leave the door open, monsters still couldn't go through; the door would close at their face.
Since the redstone torch is always providing power to the door, it will always remain open despite any external updates, which I believe is mechanics working as intended. I think that design is based on a bug in how things used to process redstone updates.
With the redstone torch under the door, and without the redstone torch being cut off, the door will always be powered and thus, unless right clicked by the player, remain in the open state (which would technically be a closed door as you have placed the door sideways).
As for what I said about it being a bug, that was just as guess as to why it worked in older versions, when in theory it should have never worked as you describe it.
The thing is, I'd come to this conclusion myself, but I find it hard to accept a mechanic as either intended or unintended if there isn't an example case where this mechanic is either exploited or causing issues; which is what I'm really trying to find out.
I gave my own example here, but this is one I came up with by myself, not one I found online.