Plug Nulls

This tool fills null cells by interpolation and extrapolation from non-null cells. The input grid is read from the Grid Directory, and the plugged grid is written to the same directory.

 Plug Nulls offers two methods for plugging nulls. Smooth Poisson Interpolation nulls cells by solving the discrete Poisson equation over the null region with Dirichlet boundary conditions set by the neighbouring known grid cells. This produces a smooth, continuous fill with no jump discontinuities at the boundaries, and preserves local gradients. Fast BFS Averages nulls cells through local averaging using a BFS (Breadth First Search) algorithm. It produces a file that is continuous at the boundaries between the original know grid cells and interpolated nulls, but can introduce large discontinuities away from the original non-null cells. It is fast.

The nulls can be re-inserted at a later stage using Restore Nulls.