Symbology¶
One of the most important tasks of GeoCat Bridge is to translate the ArcGIS Pro layer symbology to a GeoServer-compatible style. This is done by generating a Styled Layer Descriptor (SLD/SE 1.1) file, which is uploaded to GeoServer during the publication process, along with any referenced image files (e.g. PNG, SVG, etc.).
Limitations¶
Although Bridge tries to translate the symbology as closely as possible, please note that there will always be limitations:
- Not all ArcGIS Pro symbolizers and effects can be supported by GeoServer.
- 3D maps and symbols are not supported by Bridge, and neither by GeoServer.
- The Symbology Encoding (SE 1.1) model used by SLD is not as rich as the ArcGIS Pro symbology model (CIM), so some styles simply cannot be translated. The possibilities in ArcGIS Pro are almost endless, so Bridge can only attempt an approximation.
- Some more obscure or less used ArcGIS Pro symbolizers are not supported (yet) by Bridge.
- Even if a style can be properly translated, it may end up being a performance-killer on the GeoServer side. Be prepared to optimize your symbology or expressions for optimal results.
If you experience issues with the (correct) translation of your style, please read the troubleshooting section at the bottom of this page for suggestions.
GeoServer Vendor Options¶
GeoServer has its own set of vendor options that can be used to further customize the rendering of a layer, e.g. to improve labeling.
Because GeoCat Bridge is targeting GeoServer, it often makes use of these vendor options for better results. However, as these options aren't part of the official SLD specification, be aware that it may not always output strict SLD 1.1.
Supported symbolizers¶
As mentioned above, GeoCat Bridge does not support all symbolizers and effects that are available in ArcGIS Pro.
Tip
If you wish to quickly find out if your layer style can be converted, you can use the SLD Preview feature of Bridge.
Feature symbolizers¶
For all feature layers, GeoCat Bridge currently supports these symbolizer types:
All the grayed-out symbolizers are not supported by GeoCat Bridge, which are:
- Bivariate Colors1
- Unclassed Colors4
- Proportional Symbols1
- Charts3
- Dictionary2
- Heat Map3 (for point features only)
Raster symbolizers¶
For raster layers, GeoCat Bridge currently supports these symbolizer types:
All the grayed-out symbolizers are not supported by GeoCat Bridge, which are:
Other than transparency, do not use ArcGIS Pro raster effects, as these are not supported. The same also applies to enhancements like brightness, contrast, gamma, etc.
Labeling¶
GeoCat Bridge supports labeling of features, which will be added as TextSymbolizer elements in the SLD file.
You may use (basic) SQL expressions to filter the feature types you wish to label.
The values themselves may come from a data source field, a constant value, or an expression.
Just like with character markers, you should be aware that there may be font issues.
Dashed lines¶
Line symbolizers with dashed line patterns are supported by GeoCat Bridge, but may look differently as ArcGIS Pro offers more configurable options than the SLD specification.
Character markers¶
Character markers are supported by GeoCat Bridge, but be aware of font issues.
Graphic markers¶
Sometimes, your symbolizer may use a graphic marker, e.g. to show a point as a custom icon, or for a polygon fill or line stroke pattern.
GeoCat Bridge will use the PNG format for all raster graphics, and SVG for all vector graphics.
When publishing, these all receive a unique name that will be referenced in the SLD file, and both the SLD and the graphics are packaged together in a ZIP file.
Expressions¶
GeoCat Bridge currently offers limited support for Arcade expressions. Simple one-liners where some field values, logical expressions or math operations are involved are supported, but more complex expressions (e.g. with multiple nested if-statements) may not be translated correctly, if at all.
Depending on where the expression is used, the expression may be translated to a GeoServer vendor option, a CQL filter, or an OGC filter expression.
Note that in some cases, the expression may result in a very large or verbose SLD file, which could impact performance.
Fonts¶
Bridge currently does not verify whether a font exists in GeoServer.1
It also cannot upload a font to GeoServer for the following reasons:
- The font may be copyrighted (for example, the Esri marker fonts) and/or cannot be freely distributed.
- GeoServer does not provide a REST API endpoint to upload fonts.
- Even if it could upload the font, GeoServer would have to be restarted to pick it up, which disrupts the service.
Warning
When publishing, a missing font will not cause an error. However, when you try to view the layer in a WMS client, you may see that it does not render at all or shows an error.
For the best results, you should use a font that is available on both the ArcGIS Pro and GeoServer machines.
If you are not allowed to add fonts to your GeoServer target instance (e.g. because you don't own it),
a safe choice for a marker font usually is Webdings.
For labeling purposes, Arial, Georgia, Times New Roman, Trebuchet MS or Verdana are the safest choices.
Warning
Be careful when using font styles like bold or italic. These may not always render correctly in GeoServer, because there is no option to set a font style in SLD, and Bridge needs to map the style to an actual font name.
For example, when you use the Arial font in ArcGIS Pro and apply the bold style, Bridge should map it to the font that's actually named Arial Bold,
which usually is available on GeoServer as well.
Scale-dependent rendering¶
GeoCat Bridge currently only supports scale-dependent rendering for entire layers.
You may set a visibility range on a feature or raster layer, which will be translated to the MinScaleDenominator and MaxScaleDenominator elements in SLD.
However, display filters or scale-dependent rendering of individual features, classes, or labels is currently not supported.
Examples of unsupported scale-dependent rendering
Vector tiles¶
Version 1.0 of GeoCat Bridge does not support the generation and publication of vector tiles (e.g. MapLibre) yet.1
Customers who feel that this feature should have top priority may contact GeoCat BV.
Troubleshooting¶
If you encounter issues with the (correct) translation of your ArcGIS Pro style into SLD, you may want to try the following:
- Use the SLD Preview feature of GeoCat Bridge to see how your style will be translated. Look for issues in the warnings panel.
- Export the SLD file (if you are licensed to do so) and try to upload it manually to GeoServer to see what happens. You may also send it to GeoCat support for further inspection, along with a
.lyrxfile if possible, so we can improve the conversion. - If you are using a custom font (e.g. for character markers or labels), make sure that the font is available to GeoServer as well.
- Check the GeoCat Bridge log files for any errors or warnings that could indicate what went wrong. You may also want to verify the GeoServer log files.
- If the publication was successful, you could add the WMS layer to the map to verify the differences with your ArcGIS Pro layer. You could send us a screenshot of that, so we can improve the conversion.
- Finally, you could try to simplify your style in ArcGIS Pro. Especially geometric effects can be hard to translate, so if you can "flatten" these, that might make it easier to translate.