BlenderMCP

Instructions

Implementation Reference

• src/blender_mcp/server.py:724-772 (handler)

  The function `download_sketchfab_model` acts as the MCP tool handler for downloading and importing Sketchfab models into Blender. It communicates with a Blender connection to perform the actual download and processing.

  def download_sketchfab_model(
      ctx: Context,
      uid: str,
      target_size: float
  ) -> str:
      """
      Download and import a Sketchfab model by its UID.
      The model will be scaled so its largest dimension equals target_size.
      
      Parameters:
      - uid: The unique identifier of the Sketchfab model
      - target_size: REQUIRED. The target size in Blender units/meters for the largest dimension.
                    You must specify the desired size for the model.
                    Examples:
                    - Chair: target_size=1.0 (1 meter tall)
                    - Table: target_size=0.75 (75cm tall)
                    - Car: target_size=4.5 (4.5 meters long)
                    - Person: target_size=1.7 (1.7 meters tall)
                    - Small object (cup, phone): target_size=0.1 to 0.3
      
      Returns a message with import details including object names, dimensions, and bounding box.
      The model must be downloadable and you must have proper access rights.
      """
      try:
          blender = get_blender_connection()
          logger.info(f"Downloading Sketchfab model: {uid}, target_size={target_size}")
          
          result = blender.send_command("download_sketchfab_model", {
              "uid": uid,
              "normalize_size": True,  # Always normalize
              "target_size": target_size
          })
          
          if result is None:
              logger.error("Received None result from Sketchfab download")
              return "Error: Received no response from Sketchfab download request"
              
          if "error" in result:
              logger.error(f"Error from Sketchfab download: {result['error']}")
              return f"Error: {result['error']}"
          
          if result.get("success"):
              imported_objects = result.get("imported_objects", [])
              object_names = ", ".join(imported_objects) if imported_objects else "none"
              
              output = f"Successfully imported model.\n"
              output += f"Created objects: {object_names}\n"
              
              # Add dimension info if available