A Map is an item used to view explored terrain.
Obtaining[]
Crafting a Map takes 8 sheets of paper and a compass. When you first create a map, it is blank. Hold the empty map and right click to transform the empty map into a map item which gradually fills with information.
Usage[]
Mapping[]
Crafting a map creates an empty map. The map will be drawn for the first time when it is held and used (with right click). This map can then be adjusted to different zoom levels. After conversion to a drawn map item, it draws a top-down view of the player's surroundings, with North pointing to the top of the map. An oval pointer indicates the player's position on the map, and will move in real time as the player moves across the terrain shown on the map.
To record the world on a map, that specific map item must be held in the player's hands while the player moves around the world. The world will be recorded as-is during exploration, meaning that if the world is modified, a player must revisit the area while holding the map in order to update the map's view. Maps can also be cloned. A map's parameters are fixed when the map is first used, meaning the map does not remain centered on the player —the drawing snaps to a preset grid.
Other players will only be displayed on the map if they have a map in their inventory cloned from the one being looked at.
When the player leaves the area shown on a specific map, the player pointer will transform into a white pixel on that map. The marker will shrink to a small white pixel if the player is extremely far from the map's center: the radius is 320 meters per level of zoom. The pixel will move along the edge of the map to show the relative location of the player.
While maps in Hell work, all that will be shown is a scarlet and grey pattern. The only usable function is finding where you are in relation to where you made the map (the center), or have placed framed maps (green pointers). Additionally, the player pointer rapidly spins and is a bad indicator of direction.
A player can make a large piece of dot art facing upwards, center a map on it, and place that map in an item frame to create a custom picture.
Map content[]
Main article: Map item format
Each dot of a map corresponds to a variably-sized area of the world, and is always aligned to X and Z coordinates that are multiples of 8. Generally, the color of a map dot matches the color of the most common opaque material in the corresponding area, as seen from the sky. 'Minority materials' in the target area have no effect on the color of the dot, thus small features tend to be undetectable on zoomed-out maps.
Maps will also show ground up to about 15 meters below the surface of the water in seas as light blue, so you can see where the ground rises. This is not true with land above water. High elevations in the world mean light colors on the map. The map will record the surface even as you move below the surface.
Maps are 128×128 millimeters in size, giving coverage varying from 128×128 to 2048×2048 meters (8×8 to 128×128 chunks) depending on their zoom factor.
Some relevant distances: 128 meters (8 chunks) is the update radius from a player in the over world. However, it is half this (64 meters) in Hell. Also, 1024 meters is the minimum Over World distance from a Hell Portal, at which you can build another portal and expect to reach a new location in Hell. This is the distance across a 1:8 map, and also from a 1:16 map's center to its edge.
Player marker and pointer[]
Every map contains a marker that marks the position of the player, and points in the same direction as the player.