Add select along a mesh plane or line for flat structured meshes

Please add the ability to select a cell by i, j, k on a flat structured mesh, then expand this selection to be a mesh line or plane. This will have multiple steps, including selecting the cell, then expand this to be a line or plane. Note that by plane, I mean "mesh lines" and "mesh planes", not geometric (X,Y, Z) planes. So, here is what I want.

• Note - for testing, I am using the Watney CGNS dataset. 16 ranks.

• Note - This functionality is close to Extract Subset, but Extract Subset appears to not work correctly on multiple block data, multiple file data or multiple process data. Further, extract subset does not allow expansion of an already selected cell.

• Be able to select a structured cell based upon i,j (for 2 dimensions) and i,j,k (in 3 dimensions).

• (For testing, I am adding the following paragraph). Already implemented. Alternatively, I want to be able to select the cell in X, Y and Z space (0, 1 or 0, 0, 1) (already exists with Find Data). Finally, I want to be able to select a cell based on a manual GUI selection(already exists through normal selections).

• Next, I want to expand this selection along a mesh line or mesh plane. (Note - should work for 2d and 3d meshes.) For instance, with the Watney dataset, I want to select all cells at i, j, k of (,selected cell,) or (selected cell,selected cell,). Alternatively, I want to select cells at i, j and j such as (, 5, *) or (5, 5, *)

• (For testing) - Next, Extract Selection.

This is a Watney feature.