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[email protected] (minecraftathome.com)
223 points by networked on July 20, 2020 | hide | past | favorite | 74 comments

One recent notable achievement by [email protected] was the discovery[0] of the start screen panorama seed which was seen from Beta 1.8 up to 1.12. Reverse engineering Minecraft seeds is an impressive feat given that the search space is so large. The finding of Pewdiepie's survival Minecraft world seed was achieved (without [email protected]) despite him revealing his coordinates via F3 only twice in the entire series[1][2][3].

[0] https://www.reddit.com/r/Minecraft/comments/hthrmk/big_news_...

[1] https://youtube.com/watch?v=LE8ml2hZVZM

[2] https://youtube.com/watch?v=MbAymA6OAa4

[3] https://youtube.com/watch?v=qWnTRNw4mDY

I should also follow up with a technique that might be of interest to programmers. Some Minecraft blocks have textures that appear rotated in one of four ways. Turns out this rotation is pseudorandom, the rotation number is a result of seeding Java's rand.nextLong() with the (x,y,z) coordinate of that block.[0] This has been used for "malicious" purposes such as finding the location of a base from a single screenshot, which can lead to its destruction on anarchy servers. The author of the linked video used a CUDA search to find the location of a wall of netherrack.

[0] https://youtube.com/watch?v=6__hO4cc1pA

Aside: 2b2t is the most notable of MC anarchy servers. Whenever I read about it, I'm amazed at the machinations of the people that play there. It's kinda like reading Eve Online after action reports of their big battles. I've no inclination to play on 2b2t, but it's great reading all the same.

I have the same feeling about Dwarf Fortress. I absolutely love reading DF stories (see [0]), but the couple times I tried to play I just couldn't get into it.

[0] https://lparchive.org/Dwarf-Fortress-Boatmurdered/

I'm with you. Also hopeful that the DF steam release comes with a slightly easier to use UI.

If you want similarly hilarious stories, try rimworld.

I'm curious about what the implications of some of these projects will be for 2b2t. Given that the seed is known, couldn't people start finding bases from screenshots using some of these clusters of 'rotations of textures 'tricks?

Yes, these techniques have been used to find bases and destroy them. Along with the texture rotation trick, there's also the position of bedrock whose distribution is fixed in every Minecraft world, so if you show exposed bedrock during a base tour you are at risk of leaking coordinates. Natural terrain is also another factor, so share enough images of the area surrounding the base and it can be leaked similarly.

See https://www.youtube.com/watch?v=I7Jz9RMybfM


I know that Minecraft lazily generates the world, so the RNG for an arbitrary location has to be deterministic otherwise you get a mess.

Why isn't the RNG for tiles based on the world seed and the location? That's at least a billion times more search space, still deterministic.

>One recent notable achievement by [email protected] was the discovery[0] of the start screen panorama seed which was seen from Beta 1.8 up to 1.12.

Can't this be done by reverse engineering the .jar files? You'd think that the start screen would be procedually generated from a seed (eg. rather than load_world_from_file("start_screen.map"), you'd do generate_world_from_seed("my seed"), because that's way easier than hard coding in the generated world.

The start screen is just an image with some distortion.

I never thought about cracking seeds but apparrently based on location and details of the terrain its not impossible:


There is a really interesting ongoing project to find the seed used for the default world and server icons:

Part 1: https://www.youtube.com/watch?v=lbR8ZY1Nsm8

Part 2: https://www.youtube.com/watch?v=eC7f9tMslVE

Part 2 covers most of the efforts to reverse-engineer the seed.

This is quite fascinating, I hope they find it, I'm surprised they havent just emailed Mojang about it.

Part 2 of the videos mentions that Notch replied, saying that he doesn’t remember where the image is from, and that it’s likely coming from a world generated with a random seed.

Dinnerbone has also commented on reddit threads saying they support the project, but they don't think there's anything else mojang can do to help.

I appreciate Minecraft as a game.

But,instead of donating/contributing to it(because it is closed source and is paid software), i would instead donate/contribute/play https://www.minetest.net which is opensource/free alternative to Minecraft ,and minetest has better modding capabilities too.

> because it is closed source and is paid software

Is this supposed to be a negative? Should I not play my favorite games because I have to buy them?

I think the post is more about not contributing more to a closed source system like this. Play the game all you want. They are suggesting supporting an open source project instead of well funded commercial software...

An open source project that's blatantly stealing an idea and a look. Interesting that it's considered ethical to steal someone's hard work as long as you're giving it away for free.

I would link to https://www.minetest.net. The certificate on that site doesn't include the bare domain without www.

Thanks! This looks like amazing project. I just installed Minetest and learning it. :)


is good server if you want to begin with.

Use https://www.minetest.net/ because for some reason the SSL cert only covers the www subdomain.

I sometimes wonder if these @Home projects are actually a net good. Due to the lower energy efficiency of old hardware, or just the higher overhead from running multiple less power full machines, it might be a lot cheaper and more environmentally friendly if these users would directly donate the money that they are spending on their electricity bill.

The [email protected] was initially launched[1] to simulate the LHC detector and optimize machine parameters before the LHC went live. It received little to no funding for years, however without [email protected] a lot of the work would very likely not have been done on existing supercomputers[2]:

"Some 1.5x10^5 users with more than 3x10^5 PCs have been active [email protected] volunteers since its launch. This has provided significant computing power for accelerator physics studies, for which there was no equivalent capacity available in the regular CERN computing clusters. Volunteers contributing to SixTrack have delivered a sustained processing capacity of more than 45 TeraFlops."

The project has been a huge success and the studies done using it, such as this one[3], has helped to extract much more physics than anticipated[4].

So at least there are some @Home projects that have a very real impact.

[1]: https://lhcathome.web.cern.ch/about/history

[2]: http://cds.cern.ch/record/2301793?ln=en

[3]: http://cds.cern.ch/record/972345?ln=en

[4]: https://www.physicsforums.com/threads/lhc-ended-2016-proton-...

It's probably financially ok if you run it in winter when you have to heat your home.

If you're heating using electricity then it's financially equivalent. It's actually beneficial to be able to use that energy for an additional purpose (mine crypto or this) than to just burn it.

That depends on what you mean by electricity--heat pumps can achieve >100% efficiency since they move around heat instead of creating it.

I believe with heat pumps (at least ground sourced heat pumps) you can get something like 3-5 units of heat per unit of electricity. (Compared to 11-15 EERs for cooling.)

Efficiency of heat pumps are roughly the same for heating and cooling (the only difference is which side you measure from -- the hot side gets the electrical power input counted in its power). The reason EER is so high is that they used absurd units for the heat flow (BTU/h = 0.3W) so you need to divide EER by 3.4 to get the actual efficiency in unit per unit.

Most people don't have heat pumps

>For the third time in 1 week, [email protected] has broken the tallest cactus height record in normal terrain generation. I present, a 22 block tall cactus.

This is so neat!

Methodology used for pack.png : https://packpng.com/method/ Don't know if it's the same here but it definitely worth a read.

Seed finding takes quite a lot of number theory, and the following video is a good introduction: https://youtu.be/XVrR1WImOh8

Seed finding was originally important to find witch hut structures that are generated close by in order to make efficient farms. Soon speedrunners saw the utility of finding a good seed for their uses, and with the rise of pewdiepie's let's play many begun trying to figure out the seed for his world. Eventually this lead to the current project and packpng.com

Any ideas how top explain this to a 9 year old minecraft player to interest him in computing?

I guess start with hashing. You can use Minecraft (at least, the Java version) to demonstrate "hash collisions". https://www.reddit.com/r/Minecraft/comments/3229wu/these_2_d...

Perhaps you could use something like http://www.computercraft.info/ ?

You might be interested in the OpenComputers mod

This is basically virtual archeology, nice work !

I mean, it's cool, but somehow it really rubs me the wrong way. Obviously, I'm not going to tell anyone how to use their computing power, but I'm personally contributing to [email protected] instead.

Generally I agree, I also contributed to [email protected] and [email protected] The aim is somewhat "strange", but the whole value of all this may actually be not in the aim itself, but in the activity to reach it, particularly algorithms and techniques, which are developed (e.g. see @siraben comment in this thread with YouTube links to PewDiePie Minecraft seed reverse engineering) and in getting young people's interest in computer science (or STEM in general). Then in this regard the aim of this is not less valuable than looking for million-digits prime number or smallest number of moves to do a check-mate from arbitrary game position in chess, etc.

Yes, a lot of kids have learned programming becausw they wanted to develop Minecraft mods and Craftbukkit plugins. I had many colleagues doing enterprise Java that said their start was Minecraft.

If kids have a tangible goal of what they want to accomplish with coding, basically the barrier to entry no longer matters they'll figure it out.

This is why things like Minecraft and Flash were great, there is a part to the experience anyone can enjoy and accomplish but also the potential for huge depth through learning.

Same, almost a decade of programming started from modding Minecraft.

+1, this was exactly how I got my professional programming career kicked off -- learning programming from Minecraft modding and networking from there.

Yep, I was able to get started with Linux and programming in general because of Minecraft. Minecraft led me to look into servers and networking, building servers, colocating physical servers, starting a business, and many more. Minecraft, and multiplayer games in general, have done so much to get people started down the technical computing route.

I don't think many users running [email protected] will decide to jump ship and switch to [email protected] now. Therefore the harm to science-focused distributed networks should be minimal.

If anything, this project could promote the idea to new crowds, who might end up contributing resources to e.g. [email protected]

Its not a zero sum. This will increase interest in other @Home projects. It's really wonderful that thousands of people can work together to solve interesting problems - all over the world.

There seem to be a strong belief that everything what is done for scientific purpose is "useful" automatically, though it is not always the case. Occasionally massive amounts of resources of huge supercomputers and research clusters are wasted for useless tests, mistakes, typos, accidentally executed tasks, wrong input data, wrong configurations, etc, which then run for weeks or months with zero use afterwards. So indeed if this popularizes @Home projects for young people then it is very beneficial.

P.S. By saying that I'm not suggesting we should decrease the amount of resources for research, actually the opposite, since misuse is a fraction of the whole process and some discoveries would not be possible without such mistakes. We should increase the amount of resources and more importantly find people who are eager to utilize them for the sake of science, research and development.

For instance in LIGO gravitational wave detector one of PhD students accidentally misconfigured one of the black hole-neutron star merger simulation runs, so that it took months instead of days, but resulted in very detailed simulation, which then was used to study fine details of the observed signals.

Or that what is done for entertainment purposes is not useful.

There is going to be a finite number of people who are going to dedicate their computing resources (with the security, usability, and power consumption/heat issues that entails). I suspect that number is relatively small. It seems the definition of zero sum.

It's hard to rationalize virtually any notions of conservation (being green, AGW concerned, etc) with this project. Finding the seed of pewdiepie's world is somewhere between absolutely meaningless and completely meaningless.

Then what is the meaning behind the expensive, power-hungry hardware used to host his videos? Fun is a meaning!

Why is it that literally _any_ topic posted on HN has these cynical, elitist comments?

Just don't comment. Keep it to yourself.

I mean....really? What's the point of having an open discussion forum then if people are going to tell you to "keep it to yourself"? Perhaps I am cynical, but like I said - I'm not telling anyone what to do with their computing power. Just saying that using the @Home network for minecraft rubs me the wrong way, perhaps the same way using the LHC for developing makeup would. That doesn't mean that I'm right or even correct - but I do enjoy a good discussion, and indeed, my comment has spawned several good points that have made me reconsider my position. Had I just "kept it to myself" I would have never been exposed to those and still held the same view.

My initial thought was the same, but then I wondered: if this computing is done inside a home, isn't it the same as just heating the home? It would only be wasteful if the home is actually being cooled by air conditioning.

Modern heat pumps can get a coefficient of performance of around 3, meaning that for every watt of electricity going in, you get 3 watts coming out inside your home (the other two watts are being removed from the air outside). For everything that isn't a heat pump, energy in = energy released in your home (coefficient of performance=1). So in the end, you get like a 33% rebate on cpu usage via heating cost savings(very rough number, since the actual coefficient of performance varies wildly on outside air temp)...non-negligible, but it doesn't make it free unfortunately.

Heat pumps certainly sound good, but I've never been in a house that uses one for heating (or cooling).

In thermodynamic terms, an air conditioner is a heat pump hooked up the other way, though in practical terms I realize a heat pump is a device that is used for heating.

While not as mathematically elegant a comparison, you could certainly run the numbers for gas or any other heating method and find a similar cost comparision. They key point is that a computer heats the way a space heater heats, and heating your home with space heaters is expensive even in spite of the 100% efficiency at turning electricity into heat.

In the province of New Brunswick, Canada, many many homes have been (and still are) using electric baseboard heating even in midst of winter, often with less than ideal insulation in the house. Upgrading to a ductless/mini-split heat pump is seen as a pretty good option to reduce the electrical grid's load from heating, so much so that rebates have been offered by the government-owned electrical utility for people to upgrade.

I mean, they literally contributed computing power towards enjoying a video game. That's pretty much the advertised purpose of a consumer GPU.

On the plus side, all these people now have boinc installed and some might start computing for [email protected]

Kids who get into this stuff might get into [email protected] later.

How is this related to pack.png (https://packpng.com/)? Same community, some overlap, no overlap?

Essentially the same people figureheads leading the project.

See also: MineRL, a machine learning competition in which agents compete to learn how to play


The geek in me thinks this is a totally rad project, but..I'm not one to tell people how to use their computers, but building virtual worlds using computers burning actual worlds just strikes me wrong, I guess. I recognize that my use of computers for entertainment increases my carbon footprint dramatically, but recruiting cycles across the globe to inefficiently construct objects in Minecraft. idk

I don't know anything about Minecraft's internals. Why are there two seeds that produce the same result?

Your comment sparked my curiosity. Java Random[0] which is used for terraine generation uses only 48 out of the 64 bits of the seed, so there are 2^16 seeds for each possible world.[1]

Apparently only the land/ocean biome generation stage utilises the full seed.

[0] https://docs.oracle.com/javase/7/docs/api/java/util/Random.h...

[1] https://www.minecraftforum.net/forums/minecraft-java-edition...

A TL;DR for people:

'This project attempts to find the world seed of the iconic panorama image which appeared in the background of the main menu of Minecraft between 2011 and 2018.'

Essentially it's [email protected] but for finding a specific Minecraft world seed.

They actually already found the panorama world seed [1]! Currently they are working on figuring out what the tallest naturally generated cactus in Minecraft is and so far they found a world seed with a cactus that is 22 blocks tall [2]. This project however is just a filler until they get some more work done trying to figure out how to best brute force the world seed of the iconic pack.png image [3].

[1] - https://minecraftathome.com/minecrafthome/forum_thread.php?i...

[2] - https://minecraftathome.com/minecrafthome/forum_thread.php?i...

[3] - https://www.youtube.com/watch?v=eC7f9tMslVE (Interesting bit is around 7:50)

Interesting project!

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