anchor: Mesh:attachAttribute
  Attaches a vertex attribute from a different Mesh onto this Mesh, for use when drawing. This can be used to share vertex attribute data between several different Meshes.
  Mesh:attachAttribute( name, mesh )
  name string The name of the vertex attribute to attach.
  mesh Mesh The Mesh to get the vertex attribute from.
  Mesh:attachAttribute( name, mesh, step, attachname )
  name string The name of the vertex attribute to attach.
  mesh Mesh The Mesh to get the vertex attribute from.
  step ('pervertex') VertexAttributeStep Whether the attribute will be per-vertex or per-instance when the mesh is drawn.
  attachname (name) string The name of the attribute to use in shader code. Defaults to the name of the attribute in the given mesh. Can be used to use a different name for this attribute when rendering.