### Description

Use vtkShepardMethod to interpolate the scalars of a vtkPolyData. The zero-contour of the original and interpoltated scalars are extracted with vtkContourFilter. The original data is shown in red and the interpolated data in shown in yellow.

 Usage:

``` bash
ShepardInterpolation polydata [resolution]
```

where:
- polydata is a polydata file with scalar data.
- resolution is the sampling resoluton, default 100.
