Part 2: http://www.planetminecraft.com/blog/how-to-create-custom-presets-superflat-maps-part-2/

Most of you out there have probably used Superflat world designs for custom creations, right? With the addition of presets, many new types of Superflat worlds have been available, but for those of you who tried out the beta release when this was first introduced as a new feature, there was set of buttons once-upon-a-time that would allow you to build your own presets. Where did these go?

Well, first and foremost, these buttons were removed due to issues with conflicting code when trying to create the feature in the public update, and the entire design of the feature was fairly large as well, making it really time-consuming to fix, so they decided to drop the idea for the update.

Does that mean we're stuck with the custom presets that Mojang has made? Actually, not at all! They were kind enough to include a text bar that would allow for specific rewriting of the design of the superflat world you're creating. The style of code used took slightly longer to figure out than I'd like to admit, being a professional programmer myself, but I've worked out enough to share with my loyal fans and treasured subscribers.

So how can you create a superflat world? Once you get down to it, it's actually fairly simple. This post will give you the basics of setting up the lairs and deciding how many blocks thick a layer is and what block(s) make up those layers.

First, you'll need to create a new superflat world. After clicking "Create New World" and "More World Options...", set your world type to Superflat, which will enable a new button underneath marked "Customize". This is where the magic happens. Before clicking it, though, I'd highly suggest disabling automatic structures.

By default, a new superflat world in creation has three layers: Grass, dirt, and bedrock. These are the layers that we'll be editing. At the bottom right, select "Presets" and you should now see a black textbar at the top with the following:

2;7,2x3,2;1;

This line of code can be broken down into three simple parts. First, the 2 followed by a semi-colon ";" marks the bottom of the map. Similarly, the 1 surrounded by a pair of semi-colons marks the top. Both of these must be present in any custom map generation, and will be automatically added if not present. To test this theory, delete all the text in the box and simply put "3x1", without the quotes. This should make your preset stone from the Top layer to layer 3. However, if you go back to the textbar, it'll now read "2;3x1;1;" instead.

So, when creating a custom preset, the first thing you'll want to do is create the top and bottom layers. To set this up, delete all the text in the box and create the Bottom layer "2;" and the Top Layer ";1;". Now your textbox should show the following:

2;;1;

Now we create the layers we want in between the two semi-colons separating the 2 and the 1. To add a single layer of blocks, simply put the ID of the block. For example, let's create a layer of Diamond Ore blocks, because who doesn't love Diamonds? The Block ID for Diamond Ore is 56, so we'll type "56" between the 2 and the 1. Thus, our textbox should show:

2;56;1;

Back in our preset, we should now have a layer of Diamond Ore blocks from the Top Layer to Layer 1. Now let's create another layer. This time, we'll put a layer of Gold Ore blocks. To add a new layer, separate the block IDs with a comma ",". The block ID for Gold Ore blocks is 14. Thus,

2;56,14;1;

Would give us a row of Diamond Ore blocks, with a row of Gold Ore blocks above it. Note that when creating a custom preset, the layers are added from bottom to top. Thus, adding two numbers "x,y", the block with the "x" ID would be below the block with the "y" ID.

Now to create a layer in between the Gold and Diamond Ores, we simply need to add another block ID. However, what if we wanted several layers of blocks instead of just 1? We could indeed add the same block ID multiple times, but this is fairly tedious. Instead, there's a simple function to add multiple blocks. Let's add 3 layers of stone. Try:

2;56,3x1,14;1;

Now we should have a preset made of up Gold Ore on top, 3 layers of stone, and Diamond Ore on bottom. The format for adding multiple layers of blocks is "<#layers>x", or the number of layers, followed by a "x", followed by the Block ID.

That's it for this part of creating custom Superflat Presets. If this helped, diamonds are greatly appreciated, and subscribers are the primary reason I create really neat redstone builds. If you have any questions regarding anything covered in this post, please feel free to comment, as I will be happy to answer. The next post I do will be released later, and will be regarding structures and specially-generated terrain. Thank you for reading, and enjoy your own custom presets!

List of Block IDs
http://www.minecraftwiki.net/wiki/Block_id
*Use the "DEC" number, not the "HEX" number!