Symbols graphically describe, categorize, or rank geographic features and labels to locate them and show qualitative and quantitative relationships. They display graphical elements on a layout. You can optionally store, manage, and share symbols in collections called styles.
A project can include connections to many styles. The contents of project styles appear in the various symbol galleries in the application. You manage style connections from the Catalog pane or a catalog view.
Symbols are classified by the type of geometry they depict: point, line, polygon, mesh (for multipatch layers and 3D object scene layers), and text. Each symbol type has unique characteristics and properties. Symbols are built from component symbol layers. These symbol layers are classified by their graphical structure—marker, stroke, or fill. These layers are the building blocks of symbols; they combine to make rich graphical depictions. Text symbols are an exception; they have native properties but no component layers. Mesh symbols cannot contain marker symbol layers.
Fill symbol layers cover areal geometries with a single solid color (solid fill symbol layer), a series of regularly spaced lines (hatched fill symbol layer), a gradation from one color to another (gradient fill symbol layer), an image or texture (picture fill symbol layer), or a reference to a procedural rule package (procedural fill symbol layer). Stroke symbol layers can be of type solid, picture, or gradient. Marker symbol types include picture, 3D model (which are true three-dimensional objects), and shape, which are vector-based, and procedural.
Symbols in ArcGIS Pro are modeled differently than they are in ArcMap, ArcScene, and ArcGlobe. In most cases, symbols imported from existing .mxd, .sxd, .3dd documents are converted with identical appearance, but the structure and properties may be different. Symbols that were built from representation rules may result in symbols with additional symbol layers upon conversion.
Each type of symbol layer is controlled by a series of properties. The properties appear in expandable groups in the Format Symbol mode of the Symbology pane. Symbols have at least one symbol layer, but can have more, as outlined in the following table:
|Symbol type||Typical symbol layers||Role|
Draw relative to the point geometry.
Draw at specified locations relative to the line geometry.
Draw relative to the line geometry.
Draw relative to the polygon outline or within the polygon interior, depending on the marker placement setting.
Draw relative to the polygon outline.
Draw relative to the polygon interior.
Draw the surface of the mesh features. A mesh symbol can have only one fill symbol layer.
Draw the edges of 3D objects or multipatches. A mesh symbol can include a stroke symbol layer only when the fill symbol layer is a material fill. There can only be a single stroke layer, and it is limited to a solid 1-pixel-wide line.
Text symbols do not contain symbol layers
In addition to these arrangements, you can add any symbol layer to any symbol. You may encounter geometry logic errors, however, where it is not clear what symbol geometry you expect to be drawn by each layer. In these cases, a Symbol has inconsistent geometry logic warning message appears. Usually, adding effect to the layer is the best way to resolve this. Effects dynamically alter symbol geometry to create different appearances.
In some cases, an effect is added automatically to a newly added symbol layer to ensure that something logical draws. An example is adding a fill symbol layer to a point symbol. Since there isn't any polygon geometry to draw with this fill symbology, a Buffer effect is added to the fill layer. The fill symbology then draws the dynamic polygon formed by the buffer. You can configure the properties of the effect, or remove it and replace it with another one.
Basic symbol properties
In addition to the properties of symbols that come from the individual symbol layers, point, line, and polygon symbols also have a set of basic properties that relate to the symbol collectively as a whole. You access the basic symbol properties from the Properties tab in the Format Symbol mode of the Symbology pane, under the Symbol tab . You can make simple changes to a symbol here. If you have more than one symbol selected at a time—perhaps while modifying all of the symbols that draw a layer—you can only change the basic symbol properties. To access the detailed properties, you must work with one symbol at a time.