---
front:
hard: 入门
time: 分钟
---

# 生物生成

## 概述

开发者可以使用原版addon的`spawn_rules`功能控制自定义维度中的生物生成。

## spawn_rules使用方法

1.在addon的bevavior目录下新增spawn_rules文件夹

2.创建一个json文件并命名，如example.json，例子：

```python
{
  "format_version": "1.8.0",
  "minecraft:spawn_rules": {
    "description": {
      "identifier": "minecraft:netease_example",
      "population_control": "ambient"
    },
    "conditions": [
      {
        "minecraft:spawns_underground": {},
        "minecraft:brightness_filter": {
          "min": 0,
          "max": 4,
          "adjust_for_weather": true
        },
        "minecraft:height_filter": {
          "min": 0,
          "max": 63
        },
        "minecraft:weight": {
          "default": 10
        },
        "minecraft:herd": {
          "min_size": 2,
          "max_size": 2
        },
        "minecraft:density_limit": {
          "surface": 5
        },
        "minecraft:biome_filter": {
          "test": "has_biome_tag", "operator":"==", "value": "animal"
        }
      }
    ]
  }
}
```

description参数解释

| 参数 | 类型 | 解释 |
| --- | --- | --- |
| identifier | str | 该spawn rule的identifier，格式为namespace:name |
| population_control | str | 生成生物的种类，每一种类都有生成个数的限制，可选的值为：<br>animal<br>monster<br>water_animal<br>villager<br>ambient<br>cat<br>pillager |

conditions参数解释

|            Name             |      Description       |
| :-------------------------: | :--------------------: |
| minecraft:spawns_on_surface |   允许mob在地上生成    |
| minecraft:spawns_underwater |   允许mob在水里生成    |
| minecraft:brightness_filter | 允许mob生成的光照条件  |
|      minecraft:weight       | mob生成的权重，默认为0 |
| minecraft:difficulty_filter |   mob生成的困难模式    |
|       minecraft:herd        |       herd的大小       |
|   minecraft:biome_filter    |   允许mob生成的biome   |

## 自定义群系的spawn_rules

  利用condition中的minecraft:biome_filter过滤自定义群系的tag，例如群系开发模板自带的dm3等tag，或者其他自定义tag。

## demo解释

示例[CustomBiomesMod](../../13-模组SDK编程/60-Demo示例.md#CustomBiomesMod)中，对dm4于dm5两个自定义维度的生物生成做了一些调整。

- dm4

	使北极熊仅在该维度中生成，不会在其他维度的冰原群系生成。

	1. 在polar_bear的spawn_rules中设置为仅在含dm4标签的群系生成：

		（见customBiomesBehaviorPack/spawn_rules/polar_bear.json）

		```json
		"minecraft:biome_filter": [
			...,
			{"test": "has_biome_tag", "operator":"==", "value": "dm4"}
		]
		```

- dm5

	在冰原上不会生成兔子，会生成3倍大小的北极熊。

	1. 重写rabbit的spawn_rules，使其不在带dm5标签的群系生成：

		（见customBiomesBehaviorPack/spawn_rules/rabbit.json）

		```json
		"minecraft:biome_filter": {
			"any_of": [
				{
					"all_of": [
						{ "test": "has_biome_tag", "operator":"==", "value": "taiga"},
						{ "test": "has_biome_tag", "operator":"!=", "value": "mega"}
					]
				},
				{
					"all_of": [
						{"test": "is_snow_covered", "operator":"==", "value": true},
						{"test": "has_biome_tag", "operator":"!=", "value": "dm5"} //添加这一句
					]
				},
				{"test": "has_biome_tag", "operator":"==", "value":"desert"}
			]
		}
		```

	2. 新建一个名为neteasebiomes:dm5_polar_bear的自定义生物，除了设置为3倍大小外与原版北极熊一致

		（见customBiomesBehaviorPack/entities/polar_bear.json，及customBiomesResourcePack/entity/dm5_polar_bear.entity.json）

		```json
		"minecraft:scale": {
			"value": 3.0
		},
		```

		然后为其配置spawn_rules，使其仅在dm5中生成

		（见customBiomesBehaviorPack/spawn_rules/dm5_polar_bear.json）

		```python
		"minecraft:biome_filter": [
			... ,
			{"test": "has_biome_tag", "operator":"==", "value": "dm5"}
		]
		```