Omen is a map editor for Minecraft developed by osici. It originally went by the name OME and currently is in version 0.7.0. You can find the latest version at the Omen thread on the forums, or at the Omen blog.

[edit] Omen User Guide

This is a brief introduction to using the program. Omen isn't yet finished, so it has some bugs and quirks. Hopefully this guide will help make some things clear.

[edit] Installing Omen

Omen requires the Minecraft server (currently found at http://www.minecraft.net/minecraft-server.zip). You also need the latest version of Java (1.6.0 or greater). Omen070.jar contains the program, and this must be placed in the same directory as minecraft-server.jar. You don't need to have a Minecraft server running when using Omen. At present maps created with Omen can only be played on multiplayer servers.

[edit] Running Omen

You can double click Omen070.jar to run the editor. Also included is runOmen.bat, which runs the editor with more memory than the default and may be more useful for large maps. When Omen starts it will automatically try to load server_level.dat. If it cannot find this, it will create the default blank map.

[edit] Menu Options

[edit] How To

Many of these options will be self explanatory, but some are explained below.

[edit] New Map

Here you can specify the size and settings of the new map. The new map options are a blank (all air) map, several flat maps (Grass, Rock, Sand, Water, Shallow Water, Frozen Water, Snow, Lava) and seven map generators (Grassland, Desert, Winter, Hell, Mountain, Caverns and Ruins). The generators have several options. The lava and water options allow you to specify whether to add lava and water respectively to the map. The height scale slider controls the vertical stretch of the terrain. The ground height slider controls how high in the map the midpoint of the terrain lies. The smoothness slider controls how noisy the terrain is. In addition there is an option for adding an unbreakable wall around the edge of the map to prevent flooding. Also to note here is that X and Z refer to horizontal axes, and Y is the vertical axis. This is a change from the last version, but is done to be more consistent with Notch's axis labels.

[edit] Import heightmap

A heightmap is a (typically greyscale) PNG image that contains pixels of different brightness representing a 3d landscape. Brighter pixels represent higher areas. When a heightmap is imported, a 3d landscape is generated. You can create a heightmap in an image editor such as Photoshop. Heightmaps must be of the same size in the X and Z directions as the map.

[edit] Import Layer from PNG

You can import a single layer from a PNG file. Colors in the PNG will be converted to the nearest block type. Using the exact colors used by Omen for a block type will give the correct block. Again, PNGs must be of the same size, in pixels, as the X and Z directions of the map.

[edit] Import Bulk layers from PNG

As above, but for each layer in the map. For a layer i, Omen will try to load a png file layeri.png. For example, for layer 0 Omen will attempt to load layer0.png, and for layer 21 it will load layer21.png. You do not need PNG files for all layers.

[edit] Export options

Opposite of above (writes to a new file).

[edit] Edit Menu

[edit] Undo

Undo works with most map operations. It can not revert to a previous map after a new map has been created, and it cannot undo rescale and resize operations.

[edit] Scale Map

At present maps can only be scaled up, not down, so be careful with this. You can only scale by a whole number greater than zero (e.g. 2, 3, 4 etc.)

[edit] Map Size

Allows you to add or subtract a number of blocks from the ends of the maps.

[edit] Copy Layer Up

Copies the entire layer into the next layer up.

[edit] Copy Layer Down

Copies the entire layer into the next layer down.

[edit] Quick Caves

Adds air, lava, water, gold, iron and coal caves to the currently selected block type.

[edit] Add caves

Adds blobby caves of any type to the currently selected block type.

[edit] Add veins

Adds long, thin snaky caves of any type to the currently selected block type.

[edit] Smooth 2d/3d

Reduces the noise in the map, rounding off edges in 2d or 3d. The outermost 2 blocks of the map are not currently smoothed.

[edit] View Menu

The default view is of a single layer in the X-Z plane, which you can scroll through will the mouse wheel or via the buttons/menu options. The overview option is new, and provides a topographic view of the map. If the fixed overview of the map is selected, then the overview will look the same no matter which layer is being edited.