Kursach_StealthAction/.agent/skills/terrain-place-trees/SKILL.md

9.2 KiB

name description metadata
terrain-place-trees Place trees on a `Terrain` using an existing tree prototype. Either scatter `count` trees randomly across a normalized [0,1] sub-rectangle, or place trees at explicit normalized positions. Optionally clear existing trees first.
generated-by
mcp-plugin-dotnet

Terrain / Place Trees

Add TreeInstances to a Terrain. Tree positions are normalized [0,1] across the terrain.

Inputs

  • gameObjectRef — the GameObject hosting the Terrain (required).
  • prototypeIndex — index of the tree prototype to place (must already be on the terrain, default 0).
  • count — number of trees to scatter randomly (used when positions is omitted; default 100).
  • minX / minZ / maxX / maxZ — normalized [0,1] sub-rectangle to scatter within (default 0..1 on both axes).
  • positions — optional explicit normalized [0,1] XZ positions (each a Vector2, x→X, y→Z). When provided, overrides random scatter.
  • heightScale / widthScale — per-instance scale (default 1).
  • clearExisting — when true, removes existing trees before placing (default false).

Behavior

Validates the prototype index, builds TreeInstances (sampling the terrain height at each normalized position), and assigns them via TerrainData.SetTreeInstances(..., snapToHeightmap:true). Marks dirty + repaints. Runs on the Unity main thread.

How to Call

unity-mcp-cli run-tool terrain-place-trees --input '{
  "gameObjectRef": "string_value",
  "prototypeIndex": 0,
  "count": 0,
  "minX": 0,
  "minZ": 0,
  "maxX": 0,
  "maxZ": 0,
  "positions": "string_value",
  "heightScale": 0,
  "widthScale": 0,
  "clearExisting": false
}'

For complex input (multi-line strings, code), save the JSON to a file and use:

unity-mcp-cli run-tool terrain-place-trees --input-file args.json

Or pipe via stdin (recommended):

unity-mcp-cli run-tool terrain-place-trees --input-file - <<'EOF'
{"param": "value"}
EOF

Troubleshooting

If unity-mcp-cli is not found, either install it globally (npm install -g unity-mcp-cli) or use npx unity-mcp-cli instead. Read the /unity-initial-setup skill for detailed installation instructions.

Input

Name Type Required Description
gameObjectRef any Yes Reference to the GameObject containing the Terrain component.
prototypeIndex integer No Index of the tree prototype to place (must already be on the terrain).
count integer No Number of trees to scatter randomly when 'positions' is omitted.
minX number No Normalized [0,1] minimum X of the scatter sub-rectangle.
minZ number No Normalized [0,1] minimum Z of the scatter sub-rectangle.
maxX number No Normalized [0,1] maximum X of the scatter sub-rectangle.
maxZ number No Normalized [0,1] maximum Z of the scatter sub-rectangle.
positions any No Optional explicit normalized [0,1] XZ positions (Vector2: x->X, y->Z).
heightScale number No Per-instance height scale.
widthScale number No Per-instance width scale.
clearExisting boolean No If true, removes existing trees before placing.

Input JSON Schema

{
  "type": "object",
  "properties": {
    "gameObjectRef": {
      "$ref": "#/$defs/AIGD.GameObjectRef"
    },
    "prototypeIndex": {
      "type": "integer"
    },
    "count": {
      "type": "integer"
    },
    "minX": {
      "type": "number"
    },
    "minZ": {
      "type": "number"
    },
    "maxX": {
      "type": "number"
    },
    "maxZ": {
      "type": "number"
    },
    "positions": {
      "$ref": "#/$defs/UnityEngine.Vector2-1"
    },
    "heightScale": {
      "type": "number"
    },
    "widthScale": {
      "type": "number"
    },
    "clearExisting": {
      "type": "boolean"
    }
  },
  "$defs": {
    "UnityEngine.EntityId": {
      "type": "string",
      "pattern": "^[0-9]+$"
    },
    "System.Type": {
      "type": "string"
    },
    "AIGD.GameObjectRef": {
      "type": "object",
      "properties": {
        "instanceID": {
          "$ref": "#/$defs/UnityEngine.EntityId",
          "description": "instanceID of the UnityEngine.Object. If it is '0' and 'path', 'name', 'assetPath' and 'assetGuid' is not provided, empty or null, then it will be used as 'null'. Priority: 1 (Recommended)"
        },
        "path": {
          "type": "string",
          "description": "Path of a GameObject in the hierarchy Sample 'character/hand/finger/particle'. Priority: 2."
        },
        "name": {
          "type": "string",
          "description": "Name of a GameObject in hierarchy. Priority: 3."
        },
        "assetType": {
          "$ref": "#/$defs/System.Type",
          "description": "Type of the asset."
        },
        "assetPath": {
          "type": "string",
          "description": "Path to the asset within the project. Starts with 'Assets/'"
        },
        "assetGuid": {
          "type": "string",
          "description": "Unique identifier for the asset."
        }
      },
      "required": [
        "instanceID"
      ],
      "description": "Find GameObject in opened Prefab or in the active Scene."
    },
    "UnityEngine.Vector2": {
      "type": "object",
      "properties": {
        "x": {
          "type": "number"
        },
        "y": {
          "type": "number"
        }
      },
      "required": [
        "x",
        "y"
      ],
      "additionalProperties": false
    },
    "UnityEngine.Vector2-1": {
      "type": "array",
      "items": {
        "$ref": "#/$defs/UnityEngine.Vector2"
      }
    }
  },
  "required": [
    "gameObjectRef"
  ]
}

Output

Output JSON Schema

{
  "type": "object",
  "properties": {
    "result": {
      "$ref": "#/$defs/com.IvanMurzak.Unity.MCP.Editor.API.Tool_Terrain-TerrainPlaceTreesResponse"
    }
  },
  "$defs": {
    "AIGD.GameObjectRef": {
      "type": "object",
      "properties": {
        "instanceID": {
          "$ref": "#/$defs/UnityEngine.EntityId",
          "description": "instanceID of the UnityEngine.Object. If it is '0' and 'path', 'name', 'assetPath' and 'assetGuid' is not provided, empty or null, then it will be used as 'null'. Priority: 1 (Recommended)"
        },
        "path": {
          "type": "string",
          "description": "Path of a GameObject in the hierarchy Sample 'character/hand/finger/particle'. Priority: 2."
        },
        "name": {
          "type": "string",
          "description": "Name of a GameObject in hierarchy. Priority: 3."
        },
        "assetType": {
          "$ref": "#/$defs/System.Type",
          "description": "Type of the asset."
        },
        "assetPath": {
          "type": "string",
          "description": "Path to the asset within the project. Starts with 'Assets/'"
        },
        "assetGuid": {
          "type": "string",
          "description": "Unique identifier for the asset."
        }
      },
      "required": [
        "instanceID"
      ],
      "description": "Find GameObject in opened Prefab or in the active Scene."
    },
    "UnityEngine.EntityId": {
      "type": "string",
      "pattern": "^[0-9]+$"
    },
    "System.Type": {
      "type": "string"
    },
    "AIGD.ComponentRef": {
      "type": "object",
      "properties": {
        "index": {
          "type": "integer",
          "description": "Component 'index' attached to a gameObject. The first index is '0' and that is usually Transform or RectTransform. Priority: 2. Default value is -1."
        },
        "typeName": {
          "type": "string",
          "description": "Component type full name. Sample 'UnityEngine.Transform'. If the gameObject has two components of the same type, the output component is unpredictable. Priority: 3. Default value is null."
        },
        "instanceID": {
          "$ref": "#/$defs/UnityEngine.EntityId",
          "description": "instanceID of the UnityEngine.Object. If this is '0', then it will be used as 'null'."
        }
      },
      "required": [
        "index",
        "instanceID"
      ],
      "description": "Component reference. Used to find a Component at GameObject."
    },
    "com.IvanMurzak.Unity.MCP.Editor.API.Tool_Terrain-TerrainPlaceTreesResponse": {
      "type": "object",
      "properties": {
        "gameObjectRef": {
          "$ref": "#/$defs/AIGD.GameObjectRef",
          "description": "Reference to the Terrain GameObject."
        },
        "terrainRef": {
          "$ref": "#/$defs/AIGD.ComponentRef",
          "description": "Reference to the Terrain component."
        },
        "prototypeIndex": {
          "type": "integer",
          "description": "Index of the placed tree prototype."
        },
        "treesAdded": {
          "type": "integer",
          "description": "Number of trees added by this call."
        },
        "treeInstanceCount": {
          "type": "integer",
          "description": "Total tree instance count after the call."
        },
        "success": {
          "type": "boolean",
          "description": "Whether the operation succeeded."
        }
      },
      "required": [
        "prototypeIndex",
        "treesAdded",
        "treeInstanceCount",
        "success"
      ]
    }
  },
  "required": [
    "result"
  ]
}