# Radiation and hazard settings

Radiation field defaults, entity contamination, item hazards and pollution.

Registry: `hbm:radiation_config`. Files: `data/hbm/hbm/radiation_config/<group>.json`. See [Game settings](https://movblock.mov/ntm-next/wiki/game-settings.md) for loading, replacement and validation.

## radiation

`diffusivity`, `half_life_seconds`, `fog_rad`, `fog_chance` and `world_rad_effects` apply to dimensions that omit them in their [dimension radiation settings](https://movblock.mov/ntm-next/wiki/hazards-and-radiation/dimension-settings.md).

| Field | Meaning and default | Range |
| - | - | - |
| `cleanup_dead_dirt` | Dead Grass reverts to dirt on random ticks; otherwise only under a dark, light-blocking cover; default `false`. | |
| `diffusivity` | Radiation-field diffusion rate; default `10`. | `[0.000001, f64::MAX]` |
| `enable_chunk_rads` | Enables the radiation field: emission, spread, decay, fog and block decay; default `true`. | |
| `enable_contamination` | Enables entity radiation: accumulation, dose and effects; default `true`. | |
| `enable_contamination_on_ground` | A landed `hbm:contaminating` item emits into the radiation field and disappears; default `true`. | |
| `fog_chance` | Each field region above `fog_rad` spawns radiation fog with chance 1 in this value per second; default `20`. | `[1, f64::MAX]` |
| `fog_rad` | Field radiation above which radiation fog can spawn; default `100`. | `[0, f64::MAX]` |
| `half_life_seconds` | Radiation-field decay half-life in seconds; default `120`. | `[0.000001, f64::MAX]` |
| `neutron_activation` | Players carrying radioactive items gain neutron radiation, and player exposure above `neutron_activation_threshold` neutron-activates inventory items; default `false`. | |
| `neutron_activation_threshold` | Player radiation exposure in RAD/s, after protection, above which inventory items activate; default `15`. | `[0, i32::MAX]` |
| `world_rad_effects` (until NTM 1.0.1) | Radiation decays surface blocks where the field is at least 5; default `true`. `false` also stops this decay in dimensions whose settings set `world_rad_effects` to `true`. | |
| `world_rad_effects` (since NTM 1.0.1) | Radiation decays surface blocks where the field is at least 5; default `true`. | |

Example: `data/hbm/hbm/radiation_config/radiation.json`.

```json
{
  "cleanup_dead_dirt": false,
  "diffusivity": 10,
  "enable_chunk_rads": true,
  "enable_contamination": true,
  "enable_contamination_on_ground": true,
  "fog_chance": 20,
  "fog_rad": 100,
  "half_life_seconds": 120,
  "neutron_activation": false,
  "neutron_activation_threshold": 15,
  "world_rad_effects": true
}
```

## hazards

The `disable_*` keys switch off [item hazard](https://movblock.mov/ntm-next/wiki/hazards-and-radiation/item-hazards.md) types. Soot, heavy-metal and poison values are pollution levels at the affected position.

| Field | Meaning and default | Range |
| - | - | - |
| `buff_mob_threshold` | Soot above which naturally spawned hostile mobs, except glyphids, get +100% maximum health and +150% attack damage; default `15`. | finite `f64` |
| `disable_asbestos` | Disables `hbm:asbestos` hazards and asbestos accumulation; default `false`. | |
| `disable_blinding` | Disables `hbm:blinding` hazards; default `false`. | |
| `disable_coal` | Disables `hbm:coal` hazards and black-lung accumulation; default `false`. | |
| `disable_cold` | Disables `hbm:cold` hazards; default `false`. | |
| `disable_explosive` | Disables `hbm:explosive` hazards; default `false`. | |
| `disable_hot` | Disables `hbm:hot` hazards; default `false`. | |
| `disable_hydro` | Disables `hbm:hydroactive` hazards; default `false`. | |
| `disable_toxic` | Disables `hbm:toxic` hazards; default `false`. | |
| `enable_lead_from_blocks` | Breaking a block where heavy metal is at least 5 gives Lead Poisoning without Particulates head protection; default `true`. | |
| `enable_lead_poisoning` | Heavy metal above 25 at eye level gives Lead Poisoning without Particulates head protection; default `true`. | |
| `enable_poison` | Poison above 10 at eye level gives Poison or Wither without Corrosive Fumes head protection; default `true`. | |
| `enable_pollution` | Enables pollution: accumulation, spread, effects and destruction; default `true`. | |
| `enable_soot_fog` | Soot fog on clients; default `true`. | |
| `pollution_mult` | Multiplier for added pollution; [`rampant_mode`](https://movblock.mov/ntm-next/wiki/game-settings/mob_config.md#glyphids) turns exactly 1 into 3; default `1`. | `[0, f64::MAX]` |
| `soot_fog_divisor` | Soot fog scale `d`: with `e` the soot above `soot_fog_threshold`, fog colour blends by $\min(e/d, 1)$ and fog distance is render distance `/ (1 + 5e/d)`; default `120`. | `(0, f64::MAX]` |
| `soot_fog_threshold` | Soot at which soot fog starts; `rampant_mode` multiplies it by the effective `pollution_mult`; default `35`. | finite `f64` |

Example: `data/hbm/hbm/radiation_config/hazards.json`.

```json
{
  "buff_mob_threshold": 15,
  "disable_asbestos": false,
  "disable_blinding": false,
  "disable_coal": false,
  "disable_cold": false,
  "disable_explosive": false,
  "disable_hot": false,
  "disable_hydro": false,
  "disable_toxic": false,
  "enable_lead_from_blocks": true,
  "enable_lead_poisoning": true,
  "enable_poison": true,
  "enable_pollution": true,
  "enable_soot_fog": true,
  "pollution_mult": 1,
  "soot_fog_divisor": 120,
  "soot_fog_threshold": 35
}
```