citygen -- minetest city mapgenerator

A mod for minetest

Overview

Generates a procedural city with prefabricated blocks and some randomization

Recommended optional mods

• morelights for the streetlights and sewer lighting
• street_signs for the streetname signs

Updating the mod

Breaking changes can happen at any time, don't upgrade the mod if you plan on keeping you world-cityscape consistent!

How it works

The map is divided into 20 mapblocks along the z and x axis, called the "cityblock". Those 20-mapblock squares are plotted once (and cached) with a predefined layout depending on their position on the map. Streets are always aligned to the sides of the cityblock. Relevant files for the layouting mechanism:

• layout.lua
• layout_parser.lua

To ensure that the generated data is always the same a perlin-noise is derived from the current position of the cityblock. The perlin generation is done in perlin_manager.lua

A plotted cityblock looks like this (a table with x and z axes):

cityblock = {
    {
        { -- x axis
            { -- z axis
                groups = {
                    building = true,
                    edge = true
                },
                attributes = {
                    building_type = "citygen:default_building2",
                    height = 5
                },
                direction = "x+",
            },
            {
                groups = {
                    building = true,
                    edge = true
                },
                attributes = {
                    building_type = "citygen:default_building2",
                    height = 5
                },
                direction = "x+",
            },
            {
                groups = {
                    building = true,
                    corner = true
                },
                attributes = {
                    building_type = "citygen:default_building2",
                    height = 5
                },
                direction = "x+z+",
            }
        }
    },
    -- the
    root_pos = {
        z = 600,
        x = 720
    }
}

This data can be dumped on the console with the ingame command /cityblock. The current mapblock data can be dumped with /cityblock_mapblock. The "root_pos" is the lower, left mapblock of the cityblock.

This data is then passed to each mapblock that needs to be generated by the mapgen (See: mapgen.lua)

The streetnames are picked randomly (depending on the x/z position of the street) from a catalog (See: streetname.lua)

The premade schematics are deseiralized onto the map with the help of the mapblock_lib. Some buildings have different variants with custom node-replacements, see: default_buildings.lua

The schematics for a building contain 12 parts that get assembled depending on their position (bottom, corner, etc). An example of the 12 parts in "exploded" view:

Each part can be edited by copying the files (manifest- and bin-file) out of the schematics/building/ folder and placing them into the <worldfolder>/mapblocks/ folder.

Loading and saving the parts from the world and to disk is done with the mapblock_lib commands:

• /mapblock_load <name>
• /mapblock_save <name>

For example:

mkdir /my/world/mapblocks
cp schematics/street/street_all_sides* /my/world/mapblocks/

Ingame: /mapblock_load street_all_sides for loading and /mapblock_save street_all_sides to save

Licenses

Code

• MIT