[GIS] Creating polygon fill as seen in QGIS

fillpolygonqgissymbology

The polygon fill for 'Urban parcels' in the following .gif animation looks really cool.

http://changelog.qgis.org/media/images/entries/5817785cf3d18db78669c2eb2c2be0cf606c3783.gif

Does anybody know how to create a polygon fill like this?

Best Answer

First of all, this is not a new feature in 2.16, it's also possible at least with 2.14

You can combine several styles for one layer, so you can create such a visualization. In this particular case, I would recommend to combine a shapeburst fill, a line pattern fill and a simple fill. See also the following image for the different fill types:

The inner white part is created by using the colors 'transparent' and 'white' at the shapeburst fill. Try also different values for the blur, until it fits your needs.

Related Solutions

MapServer – How to Colour Polygons with Transparent Fill

Mapserver has recently introduced the concept of mask layers (a mask behaves quite like a mask in Photoshop by blending with the layer it is applied to).

The RFC describes what they do and how they can be used. By reading your answer it seems like you could use a mask layer to obtain the 'keyhole' effect you are looking for.

I am not sure if this feature made it into the 6.2 that was released a couple of weeks ago.

[GIS] Fill polygon with SVG image pattern

ok, sometimes you don't realize that you're almost at the finish line...following SE Question pointed me into the right direction and after adding some lines of code it now works :)

Working Example:

var geojsonObject = 'someGeoJSON' 
var source = new ol.source.Vector({
   features: (new ol.format.GeoJSON()).readFeatures(geojsonObject)
  });

var layer = new ol.layer.Vector({
source: source
});

var cnv = document.createElement('canvas');
var ctx = cnv.getContext('2d');
var img = new Image();
img.src = 'https://mdn.mozillademos.org/files/222/Canvas_createpattern.png';
img.onload = function() {
  var pattern = ctx.createPattern(img, 'repeat');
  layer.setStyle(new ol.style.Style({
    fill: new ol.style.Fill({
      color: pattern
    })
  }));
};

Full working example: jsfiddle

Best Answer

Related Solutions

MapServer – How to Colour Polygons with Transparent Fill

[GIS] Fill polygon with SVG image pattern

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