BlenderMCP

Instructions

Implementation Reference

• src/blender_mcp/server.py:462-519 (handler)

  The handler function for the 'set_texture' MCP tool. It is registered via @mcp.tool() decorator and implements the logic to apply a Polyhaven texture to a specified Blender object by forwarding parameters to the Blender addon via socket command.

  @mcp.tool()
  def set_texture(
      ctx: Context,
      object_name: str,
      texture_id: str
  ) -> str:
      """
      Apply a previously downloaded Polyhaven texture to an object.
      
      Parameters:
      - object_name: Name of the object to apply the texture to
      - texture_id: ID of the Polyhaven texture to apply (must be downloaded first)
      
      Returns a message indicating success or failure.
      """
      try:
          # Get the global connection
          blender = get_blender_connection()
          result = blender.send_command("set_texture", {
              "object_name": object_name,
              "texture_id": texture_id
          })
          
          if "error" in result:
              return f"Error: {result['error']}"
          
          if result.get("success"):
              material_name = result.get("material", "")
              maps = ", ".join(result.get("maps", []))
              
              # Add detailed material info
              material_info = result.get("material_info", {})
              node_count = material_info.get("node_count", 0)
              has_nodes = material_info.get("has_nodes", False)
              texture_nodes = material_info.get("texture_nodes", [])
              
              output = f"Successfully applied texture '{texture_id}' to {object_name}.\n"
              output += f"Using material '{material_name}' with maps: {maps}.\n\n"
              output += f"Material has nodes: {has_nodes}\n"
              output += f"Total node count: {node_count}\n\n"
              
              if texture_nodes:
                  output += "Texture nodes:\n"
                  for node in texture_nodes:
                      output += f"- {node['name']} using image: {node['image']}\n"
                      if node['connections']:
                          output += "  Connections:\n"
                          for conn in node['connections']:
                              output += f"    {conn}\n"
              else:
                  output += "No texture nodes found in the material.\n"
              
              return output
          else:
              return f"Failed to apply texture: {result.get('message', 'Unknown error')}"
      except Exception as e:
          logger.error(f"Error applying texture: {str(e)}")
          return f"Error applying texture: {str(e)}"