Delete Grid Nodes

Owned by Duy Pham
Last updated: 17 Sept, 2024 by Kester Scandrett

The delete grid nodes feature is used to remove unwanted cells. This is especially useful when there are cells outside the waterbody. The delete grid node feature can be used to delete a single node, a block of cells, or cells within a polygon as described below.

Delete single grid node

Once a grid is loaded in the workplace, the following steps describe how to delete the unwanted grid nodes.

  1. LMC on the grid layer in the Layer Control to select the grid want to work with.
  2. From the main toolbar, select the Delete node button then LMC on a grid node to delete node as shown in Delete Grid Nodes#Figure 1. Keeping LMC on other nodes will delete those nodes also. To end using the delete function, click the select object button from the main toolbar or press the S key.

Figure 1. Delete single grid node.

Delete grid nodes with a grid block selection

For this option, we can remove nodes inside or outside of the selected grid block.

  1. LMC on the grid layer in the Layer Control to select the grid to be worked with.
  2. From the main toolbar, press Select Object button then LMC on a grid node, the selected node will be highlighted.
  3. Hold the Shift key and LMC on another grid node (that one is not on the same grid line as the previous one), and the grid block defined by the two selected nodes will be highlighted (Delete Grid Nodes#Figure 2).

After step 3, we can delete nodes inside by accessing the Grid menu, and selecting the Delete Selected Grid Block option. Alternatively, RMC to display options then select Grid Grid Block option, as shown in Delete Grid Nodes#Figure 3. To delete grid nodes outside a grid block, select Delete Grid Nodes Outside a Block option from the RMC options, as shown in Delete Grid Nodes#Figure 4.

Figure 2. Select a grid block.


Figure 3. Delete nodes inside a grid block.



Figure 4. Delete grid nodes outside a grid block.


Delete grid nodes with a polygon

For this option, we can remove nodes inside or outside of a polygon. The polygon can be loaded from an external file or after drawing a new one. You can also use the Polygon Selection Mode to select grid nodes. 

  1. From the main toolbar, click Add a new polyline button then start drawing the polygon by LMC and end by RMC (the polygon overlays the grid) as shown in Delete Grid Nodes#Figure 5. If the polygon file is available from an external source, skip the drawing polygon steps and load the polygon file into the workplace.
  2. Select the Select object button from the main toolbar, select the overlay layer (the polygon layer) in the Layer Control panel. Then LMC on the polygon and it will be highlighted.
  3. LMC on the grid layer in the Layer Control. it means selecting the grid that we want to delete nodes.
  4. While the selected polygon is still highlighted, RMC to display various options. Select Delete Grid Nodes Inside the Selected Polygon to delete the grid nodes inside the polygon or selecting Delete Grid Nodes Outside the Selected Polygon to delete the grid nodes outside the polygon as shown in Delete Grid Nodes#Figure 6.


Figure 5. Draw a new polygon that overlays the grid.


Figure 6. Delete grid nodes inside/outside a polygon.