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Creating a drop shadow for a Polygon feature in ESRI

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The Mad Mapper

The Mad Mapper


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Hello All,

I am working on a map that could benefit from having a drop shadow to highlight an area. I would like to create the effect as seen in the example attached.

I have used a technique before that is kinda clumsy, and does not have a very nice look. I used the same polygon, to create many layers, then using the line border at various offsets, and applied increasing degrees of transparencies. See attachment "not great".

I have ArcView, and just recently got the the Spatial Analyst extension.

I am pretty sure that I can use Spatial Analyst to do a better job of the drop shadow.

I am sure I could figure it out if i spend a few nights on this (and it would be very rewarding) , but it's summer and my deadline is fast approaching. Anybody can provide any insights/clues to help me along!

PS. I would really really like to do this all in ESRI format (not using AI or the likes for post-processing).

Thanks to all and happy independence day to my neighbors to the South!


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  • not_great.png
  • dropshadow.jpg



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The ESRI blog posted some articles on figure-ground techniques.

In their dropshadow tutorial, they present a method using "representations".

See if you can use those to help. Though they may require ArcINFO...

Besides a dropshadow, you can try feathering or whitewashing:

You mention you have Spatial Analyst?

You can try:
1) Create a copy of the polygon, and offset it. The offset is where the dropshadow would sit, often South/East or South/West.
2) Use "Euclidean Distance" on the offset polygon.
3) The output raster from ED can be used as a dropshadow. Cell size and extent will affect performance, so adjust accordingly.

Note that if you do use your first technique of multiple layers with offset outlines and a transparency applied, the output PDF with all layers "below" the layer with the transparency will be rasterized. I think you know this already though =P

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