Kursach_StealthAction/.agent/skills/terrain-paint-layer/SKILL.md

name	description	metadata
terrain-paint-layer	Paint a `TerrainLayer` over a rectangular region (or the whole terrain) by writing the alphamap (splatmap) so the chosen layer has the given weight there and the other layers are reduced proportionally. Alphamap weights are normalized [0,1].	generated-by mcp-plugin-dotnet

Terrain / Paint Layer

Write the alphamap (splatmap) of a Terrain so one TerrainLayer dominates a region.

Inputs

• gameObjectRef — the GameObject hosting the Terrain (required).
• layerIndex — index of the TerrainLayer to paint (required; must already be on the terrain).
• xBase / yBase — top-left alphamap cell of the region (default 0,0).
• width / height — region size in alphamap cells. When <= 0, spans to the alphamap edge.
• strength — target normalized [0,1] weight for the chosen layer (default 1 = fully painted).

Behavior

Reads the region alphamaps via GetAlphamaps, sets the chosen layer's weight to strength and scales the remaining layers so each cell's weights sum to 1, then writes back with SetAlphamaps. Destructive. Marks dirty + repaints. Runs on the Unity main thread.

How to Call

unity-mcp-cli run-tool terrain-paint-layer --input '{
  "gameObjectRef": "string_value",
  "layerIndex": 0,
  "xBase": 0,
  "yBase": 0,
  "width": 0,
  "height": 0,
  "strength": 0
}'

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

unity-mcp-cli run-tool terrain-paint-layer --input-file args.json

Or pipe via stdin (recommended):

unity-mcp-cli run-tool terrain-paint-layer --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.
layerIndex	integer	Yes	Index of the TerrainLayer to paint (must already be on the terrain).
xBase	integer	No	Top-left alphamap X cell of the region.
yBase	integer	No	Top-left alphamap Y cell of the region.
width	integer	No	Region width in alphamap cells. <= 0 spans to the alphamap edge.
height	integer	No	Region height in alphamap cells. <= 0 spans to the alphamap edge.
strength	number	No	Target normalized [0,1] weight for the chosen layer (1 = fully painted).

Input JSON Schema

{
  "type": "object",
  "properties": {
    "gameObjectRef": {
      "$ref": "#/$defs/AIGD.GameObjectRef"
    },
    "layerIndex": {
      "type": "integer"
    },
    "xBase": {
      "type": "integer"
    },
    "yBase": {
      "type": "integer"
    },
    "width": {
      "type": "integer"
    },
    "height": {
      "type": "integer"
    },
    "strength": {
      "type": "number"
    }
  },
  "$defs": {
    "UnityEngine.EntityId": {
      "type": "string",
      "pattern": "^[0-9]+$"
    },
    "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."
    }
  },
  "required": [
    "gameObjectRef",
    "layerIndex"
  ]
}

Output

Output JSON Schema

{
  "type": "object",
  "properties": {
    "result": {
      "$ref": "#/$defs/com.IvanMurzak.Unity.MCP.Editor.API.Tool_Terrain-TerrainPaintLayerResponse"
    }
  },
  "$defs": {
    "AIGD.GameObjectRef": {
      "type": "object",
      "properties": {
        "instanceID": {
          "$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-TerrainPaintLayerResponse": {
      "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."
        },
        "layerIndex": {
          "type": "integer",
          "description": "Index of the painted TerrainLayer."
        },
        "xBase": {
          "type": "integer",
          "description": "Resolved region top-left X cell."
        },
        "yBase": {
          "type": "integer",
          "description": "Resolved region top-left Y cell."
        },
        "width": {
          "type": "integer",
          "description": "Resolved region width in cells."
        },
        "height": {
          "type": "integer",
          "description": "Resolved region height in cells."
        },
        "success": {
          "type": "boolean",
          "description": "Whether the operation succeeded."
        }
      },
      "required": [
        "layerIndex",
        "xBase",
        "yBase",
        "width",
        "height",
        "success"
      ]
    }
  },
  "required": [
    "result"
  ]
}