Procedural symbology uses script-based logic to construct complex 3D objects and textures from simple geometries to display point, polygon, or multipatch features. For example, procedural symbology can be used to render point features as realistic-looking trees, polygon features as 17th century Parisian buildings, or multipatch features with rule-based painted textures.
Procedural symbols are symbols that include a procedural symbol layer within their structure. Procedural symbol layers can be added to point and polygon symbols—but not line symbols—only when they are in a 3D context. Procedural symbol layers derive all their properties from a source file called a rule package (an .rpk file). You can configure any properties that are exposed by the rule package. As with other symbol layers, you can also connect any of these properties to feature attributes. Use the Format Symbol mode of the Symbology pane to configure the properties of procedural symbol layers.
ArcGIS Pro includes system styles with several symbols that contain procedural symbol layers. Learn how to find symbols and how to manage styles. Alternatively, you can author your own custom procedural symbol layers in CityEngine and export them as rule packages (*.rpk files) for use in ArcGIS Pro. You can also find rule packages by searching ArcGIS Online.
Add a procedural symbol layer to a 3D point or polygon symbol
In the Contents pane, click the symbol you want to add a procedural symbol layer to.
The Symbology pane appears in Format Symbol mode, displaying the current symbol.
- In the Symbology pane, switch to the Properties view and click the Structure tab to see the composition of the current symbol.
- Click Add symbol layer and choose Procedural Layer to add a new procedural layer to the structure of the current symbol.
- Consider removing all other symbol layers at this point, as they will most likely interfere with the appearance of the procedural symbol layer. On the Structure tab , click the Delete button next to a symbol layer to delete it.
- Click the Layers tab and highlight the new procedural symbol layer.
- Click the Rule button to choose a source rule package (*.rpk extension).
The properties exposed by the rule package are exposed within the symbol layer.
A procedural symbol layer leverages the logic in a rule package to draw features. Rule packages are designed such that key properties are exposed for configuration. You can customize the appearance of procedural symbol layers by altering these property values or by connecting the properties to feature attribute fields.