Summary
In ArcGIS Pro, the Create Fishnet tool and the Generate Tessellation tool can be used to generate a new grid within an existing grid. However, the new grid generated from these tools does not line up if the existing polygon feature grid is rotated. The image below shows the new grid in red is not aligned with the rotation of the existing grid in black.
This article provides the workaround to generate a new grid that aligns with the rotation of the existing polygon feature grid using the Calculate Polygon Main Angle tool and the Subdivide Polygon tool.
Procedure
- Calculate the angle of the existing grid using the Calculate Polygon Main Angle tool.
- In ArcGIS Pro, in the Contents pane, right-click the polygon feature grid layer, and select Attribute Table.
- In the table view pane, click the Add Field button.
- Create a new column with the Double data type. In this example, the new field name is MainAngle.
- On the ArcGIS Pro ribbon, on the Fields tab, click Save.
- On the Analysis tab, click Tools.
- In the Geoprocessing pane, type Calculate Polygon Main Angle in the search bar, and select Calculate Polygon Main Angle (Cartography Tools).
- In the Calculate Polygon Main Angle pane, for Input Features, click the drop-down arrow, and select the polygon feature grid layer. In this example, the layer is OriginalGrid.
- For Angle Field, click the drop-down arrow, and select the new field.
- Click Run. The main angle of the polygon feature grid layer, '2.32' is populated in the attribute table.


- Generate a new grid using the Subdivide Polygon tool.
- In the Geoprocessing pane, type Subdivide Polygon in the search bar, and select Subdivide Polygon (Data Management Tools).
- In the Subdivide Polygon pane, for Input Features, click the drop-down arrow, and select the layer of the original polygon feature grid layer.
- For Output Feature Class, type the desired name. In this example, the name is NewGrid.
- For Number of Areas, type the desired value. In this example, the value is 4.
- For Split Angle, if the main angle calculated in Step 1(i) is a positive value, add an additional '-' symbol to make the value negative. In this example, the main angle is 2.32, so -2.32 is used.
Note:
If the main angle calculated is a negative value, remove the '-' symbol for Split Angle. For example, if the main angle is -5, use 5 as the value instead.
- Click Run. The new grid is generated in the NewGrid feature class.
- Split the new grid vertically.
- In the Subdivide Polygon pane, for Input Features, click the drop-down arrow, and select the feature class containing the new grid. In this example, the feature class is NewGrid.
- For Output Feature Class, type the desired name. In this example, the name is FinalGrid.
- For Split Angle, if the main angle calculated in Step 1(i) is a positive value, minus the value from 90. In this example, the main angle is '2.32', so '87.68' is used.
Note:
If the main angle is a negative value, remove the '-' symbol, and add the value to 90. For example, if the main angle is -5, use 95 as the value instead.
- Click Run.
- Refer to ArcGIS Pro: Modify basic symbol properties for the steps to customize the appearance of the final grid.
The image below shows the final grid generated is aligned with the rotation of the original polygon feature grid.