Forest Map

Based on game build 714014 | Last updated: 2026-02-27

Overview

The forest_map.lua script is the core world generation module for the Forest biome in Don't Starve Together. It defines the procedural generation logic that constructs terrain, topology, entity placement, road networks, and seasonal settings for a new world instance. This script does not define a Component in the ECS sense; rather, it is a world generation utility module whose primary Generate function orchestrates the full process of building a forest world. It relies heavily on external modules like storygen, object_layout, bunch_spawner, ocean_gen_config, and terrain utilities (noisetilefunctions, terrain), and integrates closely with WorldSim and topology data structures during world build time.

Usage example

This module is not used as an ECS Component. It is invoked internally by the game's world generation system. The following example shows how its primary API is typically used:

local forest_map = require "map/forest_map"

local save_data = forest_map.Generate(
    "forest",       -- prefab name
    425,            -- initial map_width
    425,            -- initial map_height
    tasks,          -- table of task nodes and room assignments
    level,          -- level config table containing overrides
    "forest"        -- level_type string
)

if save_data ~= nil then
    -- World generation succeeded; save_data contains fully populated map topology and entities
    WorldArchetype:Save(save_data)
else
    -- Generation failed; likely due to validation checks (e.g., disconnected tiles, missing required prefabs)
end

Dependencies & tags

Modules required:

• map/startlocations
• map/terrain
• map/ocean_gen
• map/bunch_spawner
• map/archive_worldgen
• map/monkeyisland_worldgen
• map/object_layout
• map/storygen
• map/ocean_gen_config
• noisetilefunctions

No tags are added or removed at runtime. This module runs during world generation and does not interact with entity tags in the ECS.

Properties

No persistent instance properties exist, as this module is a utility and not an ECS Component. However, it exposes several constant tables and functions as its public API.

Property	Type	Default Value	Description
TRANSLATE_TO_PREFABS	table	internal mapping	Maps worldgen tweak names (e.g. "trees", "rabbits") to one or more concrete prefabs (e.g. {"evergreen", "deciduoustree"}). Used to expand user-facing settings into game entities.
MULTIPLY	table	density multipliers	Maps rarity names ("always", "rare", "ocean_default", etc.) to numeric density scaling factors used for entity counts.
CLUMP	table	clump size constants	Maps rarity names to maximum clump counts (e.g., "often" → 8, "always" → 30).
CLUMPSIZE	table	min/max clump size table	Maps rarity names to {min, max} clump size ranges. Used when entities spawn in clustered formations.
MULTIPLY_PREFABS	table	spawner overrides	Maps specific spawner prefabs (e.g. "tumbleweedspawner") to custom multiplier functions to adjust density adjustments for clustered or multi-item spawns.
TRANSLATE_AND_OVERRIDE	table	override+translate map	Maps worldgen settings that should be both translated to prefabs and passed as runtime overrides (e.g. "flowers" → {"flower", "flower_evil"}).
TRANSLATE_TO_CLUMP	table	clump-only mappings	Maps settings (e.g. "chess") to prefabs that should only receive clumping behavior, not density scaling.
SEASONS	table	season function map	Maps season names ("autumn", "winter", "spring", "summer") to functions that return season/temperature/precipitation configuration.
DEFAULT_SEASON	string	"autumn"	Default starting season for new worlds.

Main functions

Generate(prefab, map_width, map_height, tasks, level, level_type)

• Description: The central world generation function for the Forest biome. It constructs terrain topology (via Voronoi), spawns terrain tiles, entities, roads, and handles ocean generation if enabled. It validates required prefabs, applies worldgen overrides (e.g., rarity settings), and returns a complete save table ready for persistence.
• Parameters:
  • prefab (string): Name of the biome prefab (e.g. "forest").
  • map_width (number): Initial intended map width (modified internally based on world size).
  • map_height (number): Initial intended map height (modified internally).
  • tasks (table): Task set and node assignments defining map structure.
  • level (table): Contains overrides (user/chosen worldgen settings), required_prefabs, ocean_prefill_setpieces, and other biome-level configuration.
  • level_type (string): Arbitrary type tag used by storygen.
• Returns:
  A save table containing map data (tiles, nav, adj, topology, roads, generated, world_tile_map) and entity placements (ents). Returns nil if generation fails validation.
• Error states:
  Returns nil if topology fails to commit, if too many tiles become disconnected (>5% threshold), if critical required prefabs are missing (unless explicitly disabled in overrides), or if no valid spawnpoint is found. May also return nil if level.overrides is nil.

Events & listeners

No events are listened to or fired. This module executes synchronously during world generation and does not use the entity event system.