Why Minecraft is a Technical Feat | Explaining the Engineering Behind an Indie Icon

To those of you who are about to comment about the horrible audio balance. Yes, I already know it's messed up. Thank you for the feedback and now you don't have to comment haha.

this gives me even more respect to the people who built the simulation we live in

On top of that, the game is made in java, which really isn't meant for preformance-optimized video games

Although I prefer the new lighting system I kind of miss the old sunset, when you saw the light levels updating like a wave that swept across the world. Had something menacing and made you hurry up as night was about to come.

As a full time Minecraft modder, the game is astonishing

As a programmer, I feel like this is a great video to explain to non programmers what coding really is. While its easy to get bogged down in the details of a programming language, It's so difficult to illustrate the overarching feeling of how a programmer must approach a problem. This video does that in a very illustrative way.

when i was little i was amazed and convinced that notch himself built every single minecraft world by hand

I'm 54 years old, but god, I still love Minecraft! Starting a crisp world in an old version is pure joy!

One correction I want to say about the video, since I've worked with and researched voxel terrain generation before (specifically, an optimized implementation of opensimplex noise). The method you described in the video is a very basic 2D perlin noise heightmap which was used by the earliest versions of Minecraft, except... the method in which they use those 2D noise heightmaps is a little bit different.
More specifically, stacking layers of noise at different scales to create more variability in the terrain.
By having multiple 2D noise heightmaps to set the shape of the world. One for overall elevation, one for terrain roughness, and one for local detail. For each column of blocks, the height was (elevation + (roughness * detail)) * 64 + 64. Both elevation and roughness were smooth, large scale noises, and detail was a more intricate one.
Basically, with different layers of noise, you can do things like adding noise at different scales for roughness, or multiplying noise to get sharper terrain. This method had the great advantage of being very fast as there’s just 16*16*(noiseNum) samples per chunk to generate, but the disadvantage of being rather dull. Specifically, there’s no way for this method to generate overhangs, cliffs or canyons.
So Notch switched the system over into a similar one based off 3D noise. Instead of sampling the “ground height”, he treated the noise value as the “density”, where anything lower than 0 would be air, and anything higher than or equal to 0 would be ground. To make sure the bottom layer is solid and the top isn’t, he just added the height (offset by the water level) to the sampled result. This produces a terrain with overhangs, cliffs and canyons, by only creating a cube if the point sampled is above a certain threshold.
Another note I'd like to add is that Perlin noise had major issues where it produces artifacts along directions of the geometry. More specifically, it tends to align all of its features to the cardinal axes and to the diagonals, which was also something I could notice myself when I was messing around with it. So Ken Perlin addressed all the issues it had and made a newer and enhanced version called "Simplex noise". The word simplex refers to the generalization of a triangle to arbitrary dimensions. To put it simply, in 5:53 as an example, instead of an n-dimensional grid (as said in the video), it uses a grid of triangles instead. It is basically being faster to compute, scales up as needed (x or x,y or x,y,z etc.) and doesn't produce the visual artifacts.
Now one disadvantage of Simplex noise is that it is patented (basically no one can use it without Ken Perlin's consent). This is where OpenSimplex noise comes into play, which is different in it’s implementation from Simplex noise as to not infringe on the patent, whereas simplex noise starts with a hypercubic honeycomb and squashes it down the main diagonal in order to form its grid structure, opensimplex noise instead swaps the skew and inverse-skew factors and uses a stretched hypercubic honeycomb. The stretched hypercubic honeycomb becomes a simplectic honeycomb after subdivision. This means that 2D simplex and 2D opensimplex both use different orientations of the triangular tiling, but whereas 3D simplex uses the tetragonal disphenoid honeycomb, 3D opensimplex uses the tetrahedral-octahedral honeycomb. OpenSimplex noise also uses a larger kernel size than simplex noise. The result is a smoother appearance at the cost of performance, as additional vertices need to be determined and factored into each evaluation.
UPDATE: It’s been 8 months since I left this comment, and I’ve been itching to say that it isn’t just a single correction I wanted to point out, but some of the concepts (mostly the technical aspects of the terrain generation) explained in the video is either too simplified that it’s become inaccurate or it wasn’t even correct in the first place. And every technical aspect of the game that he wanted to bring out is common knowledge for game developers (Such as culling: 3:41) that there isn’t a single thing pointed out here that makes Minecraft a technical feat. I’m surprised by how these “full-time programmer coder hacker crackhead minecraft modder with 99 years of experience and has been developing their own terrain generation for centuries” can’t even notice a single thing wrong over how simplified this is, such as the noise terrain generation part - which was a topic I researched and worked on for fun in only a week, back in 2019. Not trying to downplay anyone or anything; this is a nice and informative video but I just wanted to get this out of the way.

This is why my attempt at re-creating Minecraft has taken more than a year thus far, and I've barely got much of anything.
I have basic rendering, and basic world generation, and that's it. 1.5 years of consistent work, and barely anything to show for it.
A lot of people say notch wasn't a great programmer - and that's true about his organization (how the code is organized and how readable it is), but when it comes to the problem solving and creative part of it, he's pretty good.

Minecraft in my opinion is a programming and mathematical wonders, people might thing that a game like minecraft would be really simple to make due to its appearances, but it really is a masterpiece

It's kinda sad that before this video went viral, it had mostly technical players discussing stuff but now there are people mostly meming around and talking about non-technical stuff. I am happy that your video went viral though, very much deserved Gabe. Keep the great work up, you're one of the most underrated tech channels I've seen. :)

I'm a software engineer and Minecraft is the game that initiated my curiosity into the field. I've thought about and wondered how some of the problems were solved in a game that had such an influential impact on my life. Thank you so much on making a video about it!

I like showing this video to idea guys. Makes them realize that coming up with some random concept is nothing compared to the enormous amount of work required to actually put together a viable product.

I don't know why but this made me tear up at the end. I just love this game so much. Great job of explaining. This is amazing!

It's funny how you say that voxels are the thing that make Minecraft work, yet the voxels are rendered as polygons.
Cool video. I learned something about various uses for Perlin Noise, which I haven't had to work with before.

It's always bugged me how people assumed that Minecraft was a simple game just because of it's 8bit inspired art style. This video does a great job of explaining just how complex it really is in a way that's easy to understand. Thank you for this!

Solid video, now I can appreciate block game even more :L

Note: Minecraft doesn't use perlin noise to figure out what height the terrain is, it actually uses it to calculate weather or not a block exists at a specific coordinate. That is what allows it to have overhangs.

Can't believe I didn't realize that the reason the height limit of minecraft used to be 256 is because rgb goes from 0-255 and they use a height map. Great video!

I tried re-creating Minecraft myself and it didn't seem that complicated at first, because all the techniques are known for a long time, but combining them as a single pers(s)on is quite the task

Why doesn't this have more views? It's really high quality.

Would definitely watch a part 2 if you've got it in ya! Great work, loved the balance of tech, math, and logic! And I love how complex problems can have relatively "simple" solutions, like how the torch only needs to directly change the block its placed on and let the math just do the rest. Beautiful.

This video was incredible. As someone who studied games programming in college, you just explained so many complex concepts in such a simple and engaging way! Kudos!!

not just a ground breaking game, the #1 game of all time by play time, sales, and basically every metric.

Nice video, only thing that bothered me is how you kinda confused "voxel rendering vs polygon rendering" and Minecraft voxels. Minecraft uses polygon rendering just like any other game, as you explained yourself shortly after. Great video nonetheless :)

I think one of the most beautiful aspects of the game is how blocks are given very specific "composable" properties.
For example: The premise of a trapdoor seems quite simple: It's a basement hatch, which opens and closes when you click it.
But then you discover that it's a lock for a water stream, it responds to redstone signals, it makes mobs walk into holes, it triggers observers, it can catapult arrows, etc.
From there on, it's just an infinite rabbithole of "emergent properties", of new things to learn.

Very interesting video! For those that enjoyed this one, I highly recommend watching Henrik Kniberg's video on a 1.18 snapshot and "how stuff works". He talks a lot about how the new terrain generation was developed, the use of noise for biome placement, making good looking mountains that "make sense", how they made underwater caves and a bunch more stuff.

The quality of this video is amazing.

I would love a sequel to this talking about other problems Minecraft had to solve with clever solutions.

Thank you for talking about this! I've always been in awe of the ingenious code behind Minecraft and It's so good to se that I'm not alone in lauding its significance!

Thank you for your effort, you explained it really well, good job. Keep it up bro i really interested to see more of this.

pretty interesting how minecraft is still a scuffed game optimization-wise even through all of this
the optimization mod community is insane. sodium pog

Initially felt maybe a bit too simplified but I don't think that's a problem at all in the end. What I think is maybe worth mentioning along the same lines is the way various block updates work - even if e.g. lighting is this simple, you very quickly start working in millions of loaded blocks, so you make sure to only actually update the light level of the surrounding blocks, and their surrounding blocks, only as far as you need. If you then extend this concept to stuff like redstone, you can see how Minecraft seemingly manages to support hundreds of thousands of blocks at once, each with their own capability for some sort of logic - just by strictly controlling when that logic gets performed.

This video is severely underrated. Hats off to you my man, amazing video. Truly changes the way one sees this seamlessly simple looking game.

i never thought minecraft was simple to make but i never knew this is how difficult it really was.
great video dude, super interesting to watch

Having invented my own Perlin Noise variant and successfully re-written much of the world generator in a mod, and later failing to make my own chunk mesher for something else, I can tell that chunk meshing is actually much harder than gradient noise like Perlin's. The concepts behind chunk meshing (which involves more than face culling) are actually quite simple, yet it's surprisingly hard to code right.

Just discovered your channel, this video is a masterpiece. I've played Minecraft [pocket edition and then java edition] consistently since 2010, and i've always loved it because of the complexity that stems from a simple survival simulation. The code for the game is extremely flawed, but that is one of the things that makes it such a fun game to play, as there are many bugs and glitches to exploit. You just earned yourself a subscriber.

I'm left hungry to know more, this look like the first chapters for a much longer journey, and now I expect you to deliver it whole.
Just, DO IT!

I remember back in 1.3.2 when I first begun playing Minecraft. I remember for a while, there being so many brightness glitches back in them days where a single overhanging or floating block would cause a maximum darkness shadow when there was no real reason for it, plus this would also allow hostile mob spawning in that shadowed area. I'm glad that's no longer a thing anymore. I've always loved Minecraft and it's mind blowing to see how far it's come over the years. :)

Love this video! just one complaint, the music can get a little overpowering. At one point I had to strain to hear you talk.. Still, keep up the good work!

It's funny that you mention rivers being used to separate bioms while flying over bioms where not a single river separates a biome, and bioms are separated without rivers lol

Fantastic video, Gabe. We're currently developing our own voxel engine for a little over a year now and it's fascinating to see how these solutions still hold up.

Amazing video, I knew about the perlin noise and perlin worms to generate the terrain but not the rest. Your explanations was great and I definitely learned a ton! Thank you.

4:32 "The problems above" lol he obviously wrote that as part of a script and didn't consider that it wouldn't make much sense in a video that doesn't flow from top to bottom like written words. Great video though, just thought that was interesting

underrated AND THIS IS A MASTER PIECE
get this man a million views

great vid, love how easily you described the more technical features.

Incredible video right there its really fascinating how a game that seems so simple can actually be insanely complex

Fantastic video! It gives a lot of intuition on how a game is made. And now it makes me even more appreciate the hard-work of developers working on such beautiful games. And BTW why the heck you have so less views! (You deserve more) Keep up the good work...

Some of the procedural terrain generation goes back older though. Look at some scenery rendering software like Bryce, and that's where fractal terrain generation (as we tend to know it now) first shows up in a way that is accessible on home computers.
So Notch was looking at other stuff that already existed when putting Minecraft together, and came up with some of the clever voxel stuff to better exploit it in terms of gameplay features. You'd also have to consider that in the pre-Microsoft era it was also made to run smoothly in a Java runtime environment. So there was quite a bit of work to make it efficient enough to run on that platform. So that may also give some consideration of all the refactoring to the game engine after Microsoft changed it to some variant of a C programming language compiled software.

Masterful explanation. Visuals are amazing t breaking down such complex concepts. Thank you.More please. Subscribed!

This really healped my understand almost everything about minecraft and It was very insightful. Thank you!

"So their game, Outcast, got left in the dust"
That's a weird line. I mean, it was actually pretty well received at the time... and it's not like it was an isolated thing - Westwood played with voxels a whole lot, using voxels for Lands of Lore 3, and for Tiberian Sun. Oh, and then there was the Blade Runner game. Meanwhile, NovaLogic used voxel technology a whole lot for games like the Delta Force franchise, because while voxels tended to produce rather grainy, crunchy visuals... they were also vastly superior at creating landscapes with natural fuzziness and depth emulating rough terrain and grass, at a time when prefab grass or dense populations of sprites cost a lot in performance.
In fact, this is a major selling point of true voxel engines to this day - they are much better at rendering detail, with the caveat that said detail will look pixelated, because it's a mass of volumetric pixels. Indeed, this is why Lands of Lore 3 and Blade Runner used voxels for its characters - the characters could afford to be more detailed than a 3D character, and more like a 2D sprite, but without losing the seamless 3D perspective changes.
Minecraft is actually a real oddity in that it uses voxel technology for its underlying world structure... but not at all for its visuals; the performance benefits of voxel technology for displaying high detail environments and characters (at least in terms of older hardware limitations) are not utilised in Minecraft.
Furthermore, while it's an ingenious creation that absolutely deserved its success... it's pretty janky, with the Java edition, to this day, struggling to run smoothly on high power machines, while the Windows 10 rebuild can run on a potato, with far greater viewing distances (demonstrating that some pretty fundamental things were holding the game back).

I think you could maybe have toned the music down a bit, especially around 2:50, because it was kinda hard to hear you over it.
Having lights be 'photorealistic' makes little difference, it's the fact that Minecraft's light is calculated when it's placed, and is saved and rendered as part of the world.
For other games, while some light is pre-calculated, the vast majority of lights interacting with the scene are dynamic, shader-based lights, which must all be processed and reprocessed each frame. The more you have, the more your performance drops.
Minecraft has the advantage in that its world is already voxellized, so adding light values to the voxels that then gets propagated from sources and saved, means they don't need to be updated again until something nearby changes.
For all the talk about how dynamic Minecraft is, yes you can change everything about the world, but without that, it's remarkably static.
You also do have the option to look at what's effectively Minecraft's source code, thanks to the various modding projects. You don't have to simply guess at the answers.

Great video ! I wish it was longer, and that we could have learned more about the other elements of the game! Great job ! 😁

Very informative. I really enjoyed this video. I'll have to watch it again for sure.

its so weird seeing this video have so little views, its really good
you also explained it really well, good job

Such an underrated channel. You've did a great job explaining all of these major points in-depth, which is rare to find these days. Well done, Gabe!

The fact that voxels were left in the dust was a crime tbh. They're amazing

i dont think ive ever been happier about the algorithm handing me a video. minecraft was a huge part of my childhood, and buying the alpha version with euros as a preteen is something ill never forget lol. years later i'm a developer, and working on my first real game. would've never thought that little block game would have such a big impact on my life.

amazing video, was thoroughly surprised when I saw how few views this had with the quality of the content. Only slight suggestion I have is to lower the music volume a bit but this is still incredibly well made!

Great video covering some of the core rendering concepts.
I would love to see more of a deep dive into the Update Loop of the game. Specifically how entities, blocks and chunks are updated with ticks and how that is adjusted based on player proximity to limit the otherwise unbounded time it could take to update all the things you've explored in an infinitely large world.

Very VERY well done my friend. I know this video is quite old but....all the points you touched on ARE STILL very valid. Bravo

this was fantastic thank you. i know a lot bout minecraft and have watched this humble game grow since alpha and seeing it from a different view makes me love it all the more and the music, after taking this hiatus from mc, it is like a cold drink on a hot day of refreshing nostalgia so again thank you for this

Hey! I know this video is already a year old, just wanted to mention something:
700k triangles isn't that much nowadays, as you said, each hero in overwatch gets 60000 triangles, but there are possibly 11 of them on screen at once (not counting the player character), which puts it at roughly the same triangle count. There's really no reason for Minecraft to be as GPU hungry as it is (even though still you are much more likely to be CPU bottlenecked), but due to how it's structured (e.g. it loads the vertex data of most objects to the GPU every frame, not leveraging the speed of the GPU in this regard) it just can't get better without a major rewrite (which hopefully happens now that it has finally updated the OpenGL version). Most of this is due to how it was made using very old technologies, such as OpenGL 2, which was already deprecated at the time.
I wouldn't really call the game a technical feat, but it does deserve some praise on the idea.

This is fascinating, you make the best in-depth videos

This is fantastic! I'd love to see a video on the new cave update and how they achieved that, since they no longer look like "worms" most of the time.
Anyway great vid, thanks!

Fascinating video. Never appreciated how much work went into the game. Thanks

This is incredible, thank you for explaining it so well! And we have a completely _new_ biome generator system in 1.18 now, which is far more complex than the 1.0-1.17 system was. Maybe you can make a video just about that, although that might be a little complicated to explain.

*G R E A T* Video. Wonderful pacing with explanations that are clear and in depth without becoming tiresome or rambly. Thank you so much for the video

Can we have more of this? Its great content, i would like to follow the rest of the Minecraft mechanichs to a technical level, since i intend to create my own Game and this has helped me so much

Never before has a game started over 10 years ago and to this day still dominate its competition by keeping its playerbase happy with ACTUAL updates and ACTUAL CARE for their fans by not just making it about themselves. Edit: read it again. Guaranteed you understand more than the replies lol.

You actually made the lighting sound more complicated than it is by combining the sky and block lighting systems. Day/Night cycles would demand constant recalculation for what you described, but for a very small price in memory footprint, lighting can be baked into block data at generation or update rather than calculated at render time.

I would love a series going into more aspects of the game!

Same with making videos. Before I started making videos I never really thought about the process. After I started I was met with a long list of problems. Cameras, lighting, audio, green screen, music, color grading… Until u start doing it u cant really appreciate how much work ppl put in doing it, and thank you very much for making such a high quality video.

Loved the video, as a programmer myself I felt fascinated with everything you explain.
I would give a 11/10 to this video but for me, the music in the background was too loud and distracting.

Awesome video, keep up the good work! I’ll be watching for sure

Awesome video! Love the way you talked about the process of building the game. Very informative and helpful to aspiring game designers like myself!

This is AWESOME!!! Thank you for sharing this!

u just got another sub bro u r amazing please make more content like this. love your voice btw

Honestly with the new caves and mountains in 1.18, I'm amazed even more.

This was a very informative video, I learned some things I didn't about the the early stages of the game development that I didn't know about before. I'm glad I do know since this is my all time favorite game. Been playing it for 10+ years.

Thank you for this TED-Talk.
Very informative and interesting.

As a game developer, this explanation can't be more accurate. You deserve more views :)

oh my god i m crying with tears in my eyes with happiness i got watching this video. i always wanted to understand this all. you earned my sub. ready to create 2d game engine with your help.

Just went through the video, very informative and great editing. my only pet peeve was that the background audio could have been a little softer as it drew my attention away from paying proper attention to the presentation. great work!

New subscriber here. I like how you script your videos. They're very professional sounding. As for the audio balance, it was nostalgic. It reminded me of the Xbox 360 days when i didn't know how to turn down the music lol

I cant even express with all of my words and actions HOW MUCH i love this game

I don't really think this video has the quality a lot of the other commenters think it has, however while I don't think the quality is very high I do think this video has really good value.
As in, the way this video expresses what is has to say isn't very polished, but despite that, what it is trying to say is still very valuable.

-Putting aside the fact you left logs floating at --0:23-- and --1:57--,- this is a really cool analysis

My kids & I have been playing this again the last couple months, & it's crazy how far this game has come since 2011 when I first started playing it for Xbox 360. Back then the game was simplistic yet so much fun that I ran a 24 hour server from my 360 that was extremely popular to the point that we had a minecart system covering the entire world. We had lots of resources 5 huge villages including some underwater glass villages. This game back then was an eye opener & now playing it 11 years later still is crazy to see how much this game still holds onto people & memories in just over a decade. Plus my kids that are up to 5 years of age love playing it with me so there's that 😁.

This was so interesting! Do you have a video that explains how Changes to the maps are saved, and how the data structures handles this?

The height is not from 0-256, that would need 9 bits to store, it's from 0-255. That is an 8 bit unsigned image, the standard.

This is fascinating. I’ve always wondered how a game do simple, yet so complex could be created. I’ve never understood how the game could calculate where a block is, and it’s relation to the world. Great video

This is probably the single most interesting video about a games structure and feats that I have ever watched

Thank you so much.
I don't play a lot of minecraft and I'm a bit older than the (current) target demographic but every time someone calls Minecraft a "dumb baby game" or a "casual" game, I'm triggered. As an amatuer programmer with a love for hardware right now I've always respected and been in awe of the underlying skeleton of this game. I've watched entire youtube tutorials on logic gates done entirely in Minecraft.
Now, instead of writing a 20 page essay or going off on a 6 hour rant and completely wasting my time, I can just send them this video.
Great job.

I want to actually say something about cave gen in Minecraft 8:35. Because I have also tried looking into how Minecraft does it, but I don't think Mojang really says publically how it's done. It is possible to look at the source code, but even it is a bit hard to understand. It seems like Perlin worms may be the way it's done, and from the phrasing in your video, it sounds like you were also unsure, even after doing research. Which is understandable.
What I do want to say about cave gen is that I did come up with a way to do cave gen that may be the true way they do it, or if it isn't, it's a better way to do it. Because from what I understand "Perlin Worms" is NOT a "purely procedural" form of generation. You can't just pick any point in the world and tell if there is a cave block (air block from cave). You have to generate the cave all at once, from start to finish. Which could cause issues if you generate a Chunk, and it causes blocks to be removed (for a cave) in places that have already been generated. So you could be mining and all of a sudden a cave just pops up in front of you.
So you need a way to be able to generate a **LARGE** cave system that spans many chunks, but be able to generate it starting from any point in space. In other words, **no origin dependency**.
I made this demo on this website that allows you to code shaders to make interesting effects.
www.shadertoy.com/view/7lX3Rl
And it shows what I'm talking about. Caves are essentially lines (geometry), and you can have an algorithm that determines if a pixel (voxel) or position in space is inside some geometry. Using the concept of grids that Ken Perlin used for Perlin noise, we can use discrete (but infinite) grids to generate random "geometry data" anywhere in space. And the lines (geometry) that are generated can be connected together randomly. And so you can pick any point in space and determine if a cave is there. Without needing to know where the cave "started".
I don't know if this is how Minecraft actually does it, but I would think that it is.
This concept can be altered to do different things as well. Cave wall diameter can be random. You could use Bezier or Spline algorithms to add curvature to the lines. You can use position distortion to add details to these lines, making it look even more organic. You could even have special data for the cave walls. Special random blocks that can show up on the sides of caves; Wall layers.

gr8 explaination, even the person with no technical background will be able to understand it, thanks to you !!

From the second I clicked on this vid, that classic Minecraft music gave me an instant wave of nostalgia.

It might be way too late now, but I want to learn more about how Minecraft's systems work. I'm trying to develop something similar (probably nowhere near as advanced), and I'm still stuck on some of the more basic parts. Perlin noise and terrain generation is simple enough, but I got stuck when it comes to biomes. It doesn't seem like Minecraft does the basic height map + temperature/humanity, at least not anymore, so how to they define the shape of the biome? In addition, how would you even find the border? Then there's also the issue of interpolation between biomes as to not have odd sudden changes in terrain generation, though I think that will be simpler to solve after figuring out biome generation.
Edit:
After rewatching this and thinking about things for a bit, I think I might have figured something out. I have yet to actually attempt it yet though.