Notch (creator of Minecraft) has started explaining his Procedural map generation

[Redrobes]

Cool Thanks, that made my day. He is talking about the large scale mapping problems and how there are errors due to the lack of accuracy of OpenGL and the limitations of 32bit int for the block positions. These are things that I specifically designed my game engine to avoid so its real cool to see that he is well behind the curve on that one. When I place a map down on my ViewingDale on another planet on a piece of land and the icon is small - like say a chair in a room, it should have the same positional accuracy as one placed in a room on the original planet a long way away. If he cant do this then he is going to be in a world of pain when it comes to people playing in large areas since his engine is going to wibble and jitter all the positions and this is what he is saying that happens - it gets more buggy as you go out. I kinda feel for something that is so popular, thats pretty lame. You cant rely on the float implementation of OpenGL at such extreme values. He is going to have to completely redesign his whole engine to cope with that if he wants to make very large scale buildings. Very interesting that - probably just to me but interesting all the same.

[guyanonymous]

Well, to be fair, the tallest a building in the game can be is 128 blocks, including the bottom bedrock layer.

And for people to move far enough for these issues to effect them involves modding/cheating, and, realistically, isn't something that 99.99999% of users would encounter during normal game-play.

Here's some user video of what happens etc.. http://www.minecraftforum.net/viewto...p?f=35&t=53577

And here's some info: "At 12,550,820 units, the normal world stops and these edgelands start. They continue until 32,000,000 units, where they suddenly stop and nothing is beyond them."

Each unit is ~1m in real-world terms, so the issues don't start until people have gone 12 550.820 km in any direction from the center of the world (the spawn point), and they can continue (albeit with distortions, slowdowns, etc) until they've gone 32,000 km from spawn.

I think he's doing OK.

That said - I'm all about endless worlds etc, and planning ahead. Imagine how much resolution we'd have if each block was 1dm instead of 1m (we'd need a bit more height in the world)...or 1cm. Let's get some 64bit goodness rolling in games and other applications people!