We consider the problem of reconstructing 3D objects via meshfree
interpolation methods. In this framework, we usually deal with large data sets
and thus we develop an efficient local scheme via the well-known Partition of
Unity (PU) method. The main contribution in this paper consists in constructing
the local interpolants for the implicit interpolation by means of Rational
Radial Basis Functions (RRBFs). Numerical evidence confirms that the proposed
method is particularly performing when 3D objects, or more in general implicit
functions defined by scattered data, need to be approximated