When working with some symbology methods in ArcGIS Pro, you choose a numeric, text, or date field to symbolize your data. The default sorting method draws the features on the map. In most cases, the default is adequate for visualization. Alternatively, you can set the feature drawing order to control the order that features draw in the layer. This can help display features on a map in a predictable and logical format.
You can also change the drawing order when the layer contains features that overlap or cover each other. For example, if you adjust the drawing order of the area field of a polygon feature layer, you can ensure that smaller polygons draw on top of larger polygons.
Feature drawing order
When a feature layer is added to a map or scene, the features are drawn. The order in which the features draw on the map is called the feature drawing order.
You can conceptualize feature drawing order by thinking about placing cards on a table, where the cards represent the layer's features. Each card has a numeric value, and they are organized from smallest to largest (the sorting method). The smallest number, one, is drawn from the deck first, and is placed first. The largest number, six, is counted last, and is placed last. Because it is placed last, it sits on top of the deck of cards, so it covers the other cards in the deck.
Feature drawing order follows this process with features in a feature layer. By default, features draw in the order they are stored or at random—this depends primarily on the underlying database. If you choose a field in the layer's attribute table, you can customize the order the features draw on the map, and which features draw on top of others.
Change the feature drawing order field
Feature drawing order is an editable property of the layer's symbology. To change the sorting method used to control feature drawing order, follow these steps:
- Select a feature layer in the Contents pane.
- On the Feature Layer tab, in the Drawing group, click the Symbology drop-down menu and choose a symbology method.
- In the Symbology pane, click the Advanced symbology options tab , and expand Feature drawing order.
- Under Drawing order field, click the drop-down menu and choose a numeric, text, or date field.
When you change this setting, the default feature drawing order is updated on the map. If you do not change this setting, the layer's features draw in the order returned by the geodatabase. You can add more than one drawing order field to the list, which further sorts the drawing order of matching values in the first defined field. Some field types, such as BLOB fields, do not appear in the menu, as they are not supported.
- Optionally, click the Sorting Method button to reverse the top-to-bottom drawing order of features.
- Lowest draws on top—The feature with the lowest value in the field (A, 0, oldest date) draws last, at the top of the layer.
- Highest draws on top—The feature with the highest value in the field (Z, 9, newest date) draws last, at the top of the layer.
Null (empty) values, which do not have a value, are an exception to the sorting mechanism. If the symbolized field contains null values, the feature drawing order follows the specifications of the database where the data is stored. For file geodatabases and shapefiles, null values draw as low values.
- If more than one drawing order field is present, click the Delete button to remove the drawing order field from the list.
The feature drawing order settings are preserved if the primary symbology is changed. If it is changed, a warning message appears to indicate that feature drawing order may impact the expected drawing order process. Additionally, the sorting method does not consider normalization settings if they are present in the data's classification.
If the data source changes after the feature drawing order is set, or the field is no longer present, you must repair the data source or choose a different field.