Library of meshes. Library of meshes. Contains a list of [Mesh] resources, each with name and ID. This resource is used in [GridMap]. Clear the library. Create a new item in the library, supplied an id. Returns the list of items. Returns the mesh of the item. Returns the name of the item. Gets an unused id for a new item. Removes the item. Sets the mesh of the item. Sets the name of the item.