NTM Radiation, Hazard and Pollution Config Reference

NTM’s radiation and hazard system is one of the most complex parts of the mod, and its configuration spans three distinct categories inside config/HBM_NTM.cfg: 13_radiation, 14_hazard, and 16_pollution. The radiation system operates at two levels: per-player contamination (which tracks how much radiation a specific player has absorbed and applies debuffs accordingly) and per-chunk world radiation (which tracks ambient radiation levels in the world and drives fog, block mutations, and mob buffing). An optional third system, PRISM, adds fully 3D resistance-aware radiation propagation but is disabled by default due to its experimental status. All options in these categories can be hot-reloaded with /ntmreload.

Chunk radiation tracking can become expensive in worlds with large contaminated areas. If you notice server-side TPS drops after nuclear events, consider increasing RADWORLD_01_amount only as far as needed and profiling with chunk radiation enabled vs. disabled.

Fog

These options control the atmospheric radiation fog that appears when a player is standing in a heavily irradiated area.

FOG_00_threshold — Radiation fog RAD threshold

Field	Value
Key	`FOG_00_threshold`
Category	`13_radiation`
Type	Integer
Default	`100`

The radiation level in RADs that a player must have accumulated before radiation fog can begin to spawn. Increasing this value makes fog appear only at higher contamination levels.

FOG_01_threshold — Fog spawn probability

Field	Value
Key	`FOG_01_threshold`
Category	`13_radiation`
Type	Integer
Default	`20`

A 1-in-N chance (per second) that fog spawns when the player has exceeded the RAD threshold. Lower values make fog appear more frequently; higher values make it rarer. A value of 1 makes fog spawn every second once the threshold is passed. The value must be at least 1; the engine resets it to 20 if it is set to 0 or below.

World Radiation

Settings controlling how high ambient radiation levels affect the world itself — including block modifications, nether ambient dose, and minimum thresholds for world effects.

AMBIENT_00_nether — Nether ambient radiation

Field	Value
Key	`AMBIENT_00_nether`
Category	`13_radiation`
Type	Double
Default	`0.1`

Ambient RAD/s dose that all players receive while in the Nether, independent of any contaminated chunks or blocks nearby. Set to 0 to make the Nether radiation-free.

RADWORLD_00_toggle — World radiation effects toggle

Field	Value
Key	`RADWORLD_00_toggle`
Category	`13_radiation`
Type	Boolean
Default	`true`

Master toggle for whether high radiation levels cause block modifications in the world (e.g. grass death, sand vitrification). Disabling this prevents all world-altering radiation effects while leaving player contamination intact.

RADWORLD_01_amount — Block operations per tick

Field	Value
Key	`RADWORLD_01_amount`
Category	`13_radiation`
Type	Integer
Default	`10`

The number of block modification operations the radiation world system is allowed to perform per tick. Higher values cause contaminated areas to transform faster but increase server CPU load. Lower values spread the work out over more ticks, reducing per-tick cost at the expense of slower propagation.

RADWORLD_02_minimum — Minimum RADs for block modification

Field	Value
Key	`RADWORLD_02_minimum`
Category	`13_radiation`
Type	Integer
Default	`20`

The minimum chunk radiation level (in RADs) required for block modifications to occur. Chunks below this threshold are ignored by the world radiation block modification system.

RADWORLD_03_regrow — Dead dirt cleanup

Field	Value
Key	`RADWORLD_03_regrow`
Category	`13_radiation`
Type	Boolean
Default	`false`

When enabled, radiation-killed grass and mycelium blocks decay into plain dirt over time, simulating environmental cleanup. Disabled by default to preserve the blasted-wasteland aesthetic.

Radiation System

These three options control the core radiation tracking infrastructure: player contamination, per-chunk ambient radiation, and the experimental PRISM propagation engine.

RADIATION_00_enableContamination — Player contamination

Field	Value
Key	`RADIATION_00_enableContamination`
Category	`13_radiation`
Type	Boolean
Default	`true`

Toggles player-level contamination tracking. When disabled, players absorb no radiation and suffer no radiation-poisoning debuffs, regardless of their environment. This is the quickest way to completely disable radiation gameplay for all players.

RADIATION_01_enableChunkRads — Chunk radiation

Field	Value
Key	`RADIATION_01_enableChunkRads`
Category	`13_radiation`
Type	Boolean
Default	`true`

Toggles the chunk-level world radiation system. Disabling this stops the game from tracking ambient radiation levels per chunk. Note that some radiation sources use an area-of-effect model rather than chunk-level tracking and are not affected by this toggle.

Chunk radiation is the most performance-sensitive part of the radiation system. In worlds with large areas of contamination (e.g. after multiple nuclear detonations), disabling this option or lowering RADWORLD_01_amount can recover meaningful server TPS.

RADIATION_99_enablePRISM — 3D PRISM radiation system

Field	Value
Key	`RADIATION_99_enablePRISM`
Category	`13_radiation`
Type	Boolean
Default	`false`

Enables the PRISM (Physics-based Radiation In a Simulated Medium) system, which replaces the flat chunk-based radiation propagation with a fully 3D, block-resistance-aware model. PRISM traces radiation through the world geometry and attenuates it based on the materials it passes through — lead blocks and concrete reduce exposure more than air or wood.PRISM is disabled by default because it is still experimental and carries a significant performance cost compared to the standard chunk-radiation system. When enabled, it replaces the ChunkRadiationManager proxy with ChunkRadiationHandlerPRISM at startup. Reloading config after enabling PRISM requires a full server restart to take effect.

PRISM is an experimental feature. It may produce unexpected results or cause server performance issues. Use only in controlled environments or for testing.

Hazard Types

NTM tracks several distinct non-radiation hazard types. Each can be individually disabled if the associated gameplay is unwanted or conflicts with another mod’s mechanics. All hazard flags live in the 14_hazard config category.

HAZ_00_disableAsbestos — Asbestos hazard

Field	Value
Key	`HAZ_00_disableAsbestos`
Category	`14_hazard`
Type	Boolean
Default	`false`

When set to true, all asbestos-related hazards are disabled. Asbestos dust causes lung damage (fibrosis-style effects) over time when inhaled; disabling this removes all such effects.

HAZ_01_disableCoaldust — Coal dust hazard

Field	Value
Key	`HAZ_01_disableCoaldust`
Category	`14_hazard`
Type	Boolean
Default	`false`

When set to true, all coal dust hazard effects are disabled. Coal dust can cause respiratory damage when players are exposed to it in quantity.

HAZ_02_disableHot — Hot hazard

Field	Value
Key	`HAZ_02_disableHot`
Category	`14_hazard`
Type	Boolean
Default	`false`

When set to true, all “hot” hazards (heat-related damage from superheated materials and environments) are disabled.

HAZ_03_disableExplosive — Explosive hazard

Field	Value
Key	`HAZ_03_disableExplosive`
Category	`14_hazard`
Type	Boolean
Default	`false`

When set to true, all explosive material hazards are disabled. This affects items and blocks flagged as explosive hazards in NTM’s hazard registry, separate from actual explosion events.

HAZ_04_disableHydroactive — Hydroactive hazard

Field	Value
Key	`HAZ_04_disableHydroactive`
Category	`14_hazard`
Type	Boolean
Default	`false`

When set to true, all hydroactive hazards (materials that react dangerously with water) are disabled.

HAZ_05_disableBlinding — Blinding hazard

Field	Value
Key	`HAZ_05_disableBlinding`
Category	`14_hazard`
Type	Boolean
Default	`false`

When set to true, all blinding hazards are disabled. These typically represent highly reactive or luminous materials that can impair player vision.

HAZ_06_disableFibrosis — Fibrosis hazard

Field	Value
Key	`HAZ_06_disableFibrosis`
Category	`14_hazard`
Type	Boolean
Default	`false`

When set to true, all fibrosis hazards are disabled. Fibrosis represents progressive lung damage caused by long-term particle inhalation (distinct from the coal-dust hazard).

Pollution & Environmental

The 16_pollution category controls NTM’s industrial pollution system, which tracks airborne soot and heavy metals separately from radiation. Pollution affects mob strength, player health, and visibility.

POL_00_enablePollution — Pollution system toggle

Field	Value
Key	`POL_00_enablePollution`
Category	`16_pollution`
Type	Boolean
Default	`true`

Master toggle for the entire pollution system. When disabled, none of the following pollution options have any effect, and no pollution values are tracked or applied.

POL_01_enableLeadFromBlocks — Lead poisoning from block-breaking

Field	Value
Key	`POL_01_enableLeadFromBlocks`
Category	`16_pollution`
Type	Boolean
Default	`true`

When enabled, breaking blocks in areas with high heavy-metal pollution (lead, etc.) exposes the player to lead poisoning. Disable to remove this mining hazard without disabling the rest of the pollution system.

POL_02_enableLeadPoisoning — Ambient lead poisoning

Field	Value
Key	`POL_02_enableLeadPoisoning`
Category	`16_pollution`
Type	Boolean
Default	`true`

When enabled, simply being present in a heavy-metal-polluted area (without breaking blocks) also poisons the player. This is separate from the block-breaking vector above.

POL_03_enableSootFog — Smog visibility

Field	Value
Key	`POL_03_enableSootFog`
Category	`16_pollution`
Type	Boolean
Default	`true`

Toggles the visible smog/soot-fog rendering effect. When disabled, smog effects are invisible even if the underlying pollution values are still being tracked.

POL_04_enablePoison — Area poison effect

Field	Value
Key	`POL_04_enablePoison`
Category	`16_pollution`
Type	Boolean
Default	`true`

When enabled, players in areas with high chemical pollution (non-radiation, non-lead) will receive poison status effects.

POL_05_buffMobThreshold — Mob buff soot threshold

Field	Value
Key	`POL_05_buffMobThreshold`
Category	`16_pollution`
Type	Double
Default	`15.0`

The amount of ambient soot required before naturally spawning mobs receive a strength buff from the pollution. Higher values require denser industrial pollution before mobs become tougher.

POL_06_sootFogThreshold — Smog visibility threshold

Field	Value
Key	`POL_06_sootFogThreshold`
Category	`16_pollution`
Type	Double
Default	`35.0`

The minimum soot level required for smog to become visible. Below this value the sky remains clear even if soot is present.

POL_07_sootFogDivisor — Smog density divisor

Field	Value
Key	`POL_07_sootFogDivisor`
Category	`16_pollution`
Type	Double
Default	`120.0`

Controls smog density once the threshold is exceeded. A higher divisor requires proportionally more soot to achieve the same visual fog density. Increase this if smog appears too thick at moderate pollution levels.

POL_08_smokeStackSootMult — Smokestack soot multiplier

Field	Value
Key	`POL_08_smokeStackSootMult`
Category	`16_pollution`
Type	Double
Default	`0.8`

Multiplier applied to soot generated by smokestacks. Values below 1.0 reduce soot output; values above 1.0 amplify it. The default 0.8 slightly reduces smokestack soot relative to the base rate.

Introduction

Core Concepts

Configuration

NTM Radiation, Hazard and Pollution Config Reference

Fog

World Radiation

Radiation System

Hazard Types

Pollution & Environmental

Build docs developers (and LLMs) love

Introduction

Core Concepts

Configuration

Documentation Index

​Fog

​World Radiation

​Radiation System

​Hazard Types

​Pollution & Environmental

Build docs developers (and LLMs) love

Fog

World Radiation

Radiation System

Hazard Types

Pollution & Environmental