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Technical Article   Problem:  Polygons are divided in tiny strips when exported to EPS, PDF, SVG, or AI Illustrator

Article ID: 29950
Bug Id: N/A
Software:  ArcGIS - ArcEditor 9.0, 9.1, 9.2 ArcGIS - ArcInfo 9.0, 9.1, 9.2, 9.3 ArcGIS - ArcView 9.0, 9.1, 9.2 ArcGIS Engine Runtime 9.0, 9.0.1, 9.1, 9.2 ArcGIS Server 9.0, 9.0.1
Platforms:  Windows NT 4.0, 2000, XP

Description

When opened in an external editor like Adobe Illustrator, .EPS, .PDF, .SVG, or .AI export files display some large polygons divided into separate pieces.

For example: This map contains a polygon with a large number of vertices. This screenshot shows the polygon selected in ArcMap: -show me-

[O-image] ArcMap Polygon Dicing Selection Screenshot


Selecting the same polygon in the resultant .AI file exported from ArcMap and displayed in Adobe Illustrator shows that the polygon has been split into smaller pieces: -show me-

[O-image] Adobe Illustrator polygon dicing screenshot

Cause

This is called polygon dicing, and it occurs when drawing or exporting polygons that have more vertices than a certain threshold. For .PDF, .EPS, and .SVG formats, the default threshold is 5,000 vertices. For the Illustrator format, .AI, the default threshold is 8,000 vertices.

The purpose of polygon dicing is to:
• Speed up on-screen drawing and
• Prevent interpretation failures when files with large polygons are opened with older software or on a machine with limited resources.

Solution or Workaround

Reduce the effect of polygon dicing by simplifying the polygon data or exporting at a lower resolution. If this is not possible or does not help, increase the vertex threshold at which polygon dicing occurs.

 These steps only apply to ArcGIS version 9.0 and later.


 The instructions below include making changes to essential parts of your operating system. It is recommended that you backup your operating system and files, including the registry, before proceeding. Consult with a qualified computer systems professional, if necessary. ESRI cannot guarantee results from incorrect modifications while following these instructions. Therefore, use caution and proceed at your own risk.



  1. Start the Windows Registry Editor by navigating to Start > Run, typing regedit and clicking OK.
  2. Expand HKEY_CURRENT_USER\Software\ESRI\Export and and then select the registry key 'ExportObjectsParams'.
  3. The ExportObjectsParams registry key contains a MaxVertices registry value for each of the five vector export formats:
    'ai_MaxVertices'
    'emf_MaxVertices'
    'eps_MaxVertices'
    'pdf_MaxVertices'
    'svg_MaxVertices'


    The number in the registry data field determines the maximum number of vertices a polygon can have before the exporter will dice the polygon into multiple parts.

    Change the value to a higher number by double-clicking the registry data icon, changing the edit window to 'decimal' mode, and entering the higher number in the text box. The changes will take effect the next time a map is exported to that format.

    To find the optimal value for your workflow, you may need to experiment. Higher limits typically cause slower display and edit times in Illustrator and Acrobat.

Related Information


Created: 11/21/2005
Last Modified: 9/10/2008

Article Rating: (1)
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Comments

By earthman3 - 12/13/2012 6:27 PM

The article needs to be updated.

I found that if polygons are displayed with a non-zero value of transparency in GIS they will export into these strips. Setting transparency to zero on the Display tab solves the issue. You can then apply a transparency to your polygons in Illustrator. If you have other items as a basemap, such as satellite imagery or a topographic raster (DEM or hillshade), I also recommend exporting each as separate Illustrator files (i.e. export just the polygons, just the imagery, then just the DEM/hillshade. Then rebuild these elements that you exported as separate Illustrator files into one, master Illustrator file. Using copy/paste-in-front makes layering the items in the appropriate spatial location. It's a few extra, but quick, steps that I've found to provide the desired results.

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