Note that this reference documentation is identical to the help that is displayed in MATLAB when you type “help ft_transform_headshape”.

  FT_TRANSFORM_HEADSHAPE applies a homogenous coordinate transformation to a
  structure with headshape and fiducial information.
 
  Use as
    shape = ft_transform_headshape(transform, shape)
 
  See also FT_READ_HEADSHAPE