  We introduce meshfree finite difference methods for approximating nonlinear
elliptic operators that depend on second directional derivatives or the
eigenvalues of the Hessian. Approximations are defined on unstructured point
clouds, which allows for very complicated domains and a non-uniform
distribution of discretisation points. The schemes are monotone, which ensures
that they converge to the viscosity solution of the underlying PDE as long as
the equation has a comparison principle. Numerical experiments demonstrate
convergence for a variety of equations including problems posed on random point
clouds, complex domains, degenerate equations, and singular solutions.
