topic Re: Constant opacity when overlapping graphics in ArcGIS JavaScript Maps SDK Questions

Constant opacity when overlapping graphics

MostafaAsadi — Fri, 07 May 2010 21:33:15 GMT

Hi,

I have a buffer search that returns some results on the map. The results are then displayed with a solid circle around them. The problem is, when these buffer circles overlap each other they get darker. Is there a way I could make them preserve their opacity when they overlap?

Here's the piece of code:

geoService.buffer(params, dojo.hitch(this, function(graphics) {
 //console.debug("Buffer completed");
 var symbol = new esri.symbol.SimpleFillSymbol("solid", new esri.symbol.SimpleLineSymbol(esri.symbol.SimpleLineSymbol.STYLE_NULL), new dojo.Color([255, 255, 0, 0.5]));
 var gBuffer = new esri.Graphic(graphics[0].geometry, symbol);
 
 this.map.graphics.add(gBuffer);
}));

Re: Constant opacity when overlapping graphics

DerekSwingley — Mon, 10 May 2010 17:57:01 GMT

How about unioning your buffer geometries using a geometry service each time a new buffer is added? I hacked up the buffer a point sample to generate the attached screen shot.

Re: Constant opacity when overlapping graphics

MostafaAsadi — Wed, 19 May 2010 20:44:28 GMT

Thanks! I didn't know about the union property.