[MC-107623] Observer Instant wire

When observers are placed back to back all facing the same direction, when the leading observer is updated the last instantly outputs. This can be easily exploited as a form of instant wire.

Linked issues

relates to 1

MC-107410 Observer block outputs single game tick pulse, not single redstone tick pulse Resolved

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Comments 22

Matthew Laukala 2016-09-28T22:42:10Z

There is already instant wire in minecraft that is a lot cheaper to create.

Ryan Leach 2016-09-29T16:53:30Z

Not only this, but spacing them by 1 block is NSEW UD dependent.

Either remove the functionality, or make it symmetric.

Zed Ontargs 2016-09-29T22:20:13Z

Simply adding a delay to the observer might cause more problems than it fixes. Re-posting a comment of mine from Reddit:

"Right now, if an observer triggers a piston with no delay, it doesn't react to the piston head passing in front of it. If you add in a delay, you get an update-loop caused by the piston head. Try it with a repeater and see.

"In order to solve that, unless Mojang builds a minimum cycle length into the observer block, you'd need an entire control circuit to make the piston ignore the piston-caused updates. It would also mean that we'd need to time everything else around the lockout period, making observers even less useful."

I hope, if this does get "fixed", it does so in a way that won't make it harder to use than any of the existing powered-block or quasi-connectivity BUD systems. It'd be a shame to turn it into a "furnace minecart" situation right after adding it.

Zed Ontargs 2016-09-29T23:56:11Z

A reply to the Reddit suggestion that Mojang make the observer weakly power blocks instead of strongly powering them:

"Hmm. After experimenting with the assumption that it'd weakly power blocks, we run into a new problem: you can't use it in a conventional BUD-triggered piston setup anymore. The single point of redstone power can't reach any useful distance without a delay-causing repeater, which leads to the update loop.

"I had to use a chain of observers and dust in order to instantly pass the signal, which makes these messes (strongly powered on the left, weakly powered on the right): http://sli.mg/a/ZtIbp3

"If Mojang goes that route, I hope they increase the power of the output signal (if that's possible for a weak source), otherwise it's less useful than the makeshift ones we have now."

Andrei G 2016-10-05T10:18:45Z

The instant reaction time is potentially very harmful to the future of Redstone. So far, every Redstone component leading up to the observer has followed the philosophy of purposely having a built-in delay even when delaying signals was not its primary use. This instant reaction feature of the Observer is a major break in that overarching concept.

Unless the Observer gets a delay, it will end up replacing Redstone Dust for the majority of purposes, not least of all due to the Observer being so much more convenient to use in nearly any situation since it not just gives off power for other components to use but itself powers blocks directly, a feature that we have not seen before for blocks that did not require a basis to be placed on like the torch, repeater, dust, etc.

Another major advantage over dust is the way its updates are processed: not only is its update order when chained with other Observers much more predictable than that of a Redstone dust line, but a chain of Observers will create exponentially less lag than a line of redstone, and that alone will be reason enough to choose the Observer over dust every time the choice is given.

It seems to me, a near total replacement of dust by the otherwise very thoughtfully implemented Observer cannot have possibly been the intention behind this block, but i would welcome a comment from Mojang on this.

12 more comments

Matthew Laukala 2016-10-05T16:52:09Z

I do agree that this block will change how people use redstone but that is not necessarily a bad thing. It can be used to make certain redstone components smaller. It will also enable more complex components. But it does come at an extra cost. In my opinion, that cost should be a bit more. But with all that said, before this update in my vanilla world, I use hoppers to remote load chunks and instant redstone in combination with an enderporter to teleport thousands of blocks instantly.

In conclusion, I believe that the current state of the observer block helps to evolve redstone into something better but should be a bit more costly. I believe that it should cost at least 2 or more redstone to craft it. perhaps a block of redstone.

EDIT: Didn't realize it already takes 2 redstone to craft when I wrote this post.

ilmango 2016-10-05T19:39:44Z

As long as redstone is unnecessarily laggy (see https://bugs.mojang.com/browse/MC-81098) I'll gladly replace every piece of redstone dust with observers. I've been working with redstone in the 1.11 snapshots and redstone dust won't be replaced 1 by 1 by the observer. There are still a lot of situations where you need RS dust.The observer is just one more tool, that finally helps us making our contraptions less laggy.

kades 2016-11-03T15:51:55Z

Guess what, if you place redstone dust in a line, and power it, the whole line powers at once. This can be easily exploited as a form of instant wire.

Kaisheng21 2016-11-03T17:13:53Z

Why was instant wire a bad thing? Also, how does the observer function now?

user-f2760 2016-11-03T17:16:41Z

It has a delay now.

Joseph Zimmerman 2016-11-03T17:45:24Z

Really?

[media]

? Can someone please tell me what was wrong with it being the way it was? Who approved this change?

user-f2760 2016-11-03T18:03:05Z

A large amount of them in a chain could crash the game, that's why it got changed.

kades 2016-11-03T18:07:58Z

Yet you guys ignore the issue of redstone dust causing thousands of unnecessary block updates which can also crash the game.

user-f2760 2016-11-03T18:10:37Z

They don't ignore it, that requires a complete rewrite of redstone.

Joseph Zimmerman 2016-11-03T18:58:55Z

How does Pocket Edition handle that? If people want to make an observer line 1000 long, then they should expect the game to crash.

Andrei G 2016-11-03T19:06:43Z

Don't know if the mods here have direct contact to the devs, but just wanted to say, great snapshot guys! You listened to the community's feedback and made observers less op by giving them delay, and at the same time you kept them a very useful block by giving them back the 1 tick pulse output. I also love how you made them not detect block updates (which was causing the controversial "air block chaining") but rather complement instead of completely replace the classic piston BUDs by being block state change detectors. Not only that, you fixed the rest of the redstone you broke recently, which is as it should be. This is how you keep people motivated to play minecraft, this is how you keep a great game great! Keep it up. One tip: if you want to make observers the best block they can be, let them output signal strength 1 again. That was a very unique feature that made them even more useful than they already are. Thanks!

user-f2760 2016-11-03T19:33:12Z

Pe redstone is completely different code, it never had issues like that.

Bachsau 2016-11-03T19:46:19Z

@joezim007 A player should never expect the game to crash and never worry about it. Things can work or not but should never result in a crash.

kades 2016-11-03T19:49:55Z

Panda4994 has made a mod that fixes redstone dust already.

user-f2760 2016-11-03T20:09:34Z

The devs tried that already, but they didn't like the implementation.

Kaisheng21 2016-11-03T21:37:58Z

There is already instant wire in MC. Why is that allowed while observers have to be nerfed?

Joseph Zimmerman 2016-11-03T21:53:47Z

observers I guess need to be nerfed because they don't have the max 15 signal distance like "instant wire" does, so without the delays, they can cause issues. The more I think about it, this seems like a proper fix, though I wish that things had been coded in a way that nerfs like this weren't necessary. It continues to break things that previously worked, but they only worked in snapshots, which obviously meant you couldn't trust them anyway.

Obviously it would be a TON of work, but I'm curious how much thought has gone into a refactor of the redstone code, and potentially other code as well, to ensure changes and additions are simpler to make and to help eliminate undesirable behavior. I'm not expecting it, but I'm curious if it has been discussed.