Manually add feature with ol3

Use ol3 to manually add a polygon to a vector source/layer and have it render on the map

by Kieveli

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/ol3/3.6.0/ol.css">
<script src="http://openlayers.org/en/v3.0.0/build/ol-debug.js"></script>
<div id="map" class="map"></div>

JavaScript

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

var map = new ol.Map({
  layers: [
      new ol.layer.Tile({
          source: new ol.source.MapQuest({layer: 'sat'})
      }),
      new ol.layer.Vector({
          source: vectorSource
      })
  ],
  target: 'map',
  view: new ol.View({
    center: [-11000000, 4600000],
    zoom: 4
  })
});

var thing = new ol.geom.Polygon( [[
    ol.proj.transform([-16,-22], 'EPSG:4326', 'EPSG:3857'),
    ol.proj.transform([-44,-55], 'EPSG:4326', 'EPSG:3857'),
    ol.proj.transform([-88,75], 'EPSG:4326', 'EPSG:3857')
]]);
var featurething = new ol.Feature({
    name: "Thing",
    geometry: thing
});
vectorSource.addFeature( featurething );