title: Updating entities in Cesium
body: <p>I have a few entities, who's positions are being set using a CallbackProperty function. </p>
  
  <pre><code>cesium.renderPolygon = function(mapContext, polygon, existingEntity) {
              var p;
              if (existingEntity) {
                  p = existingEntity;
              } else {
                  var polOpts = getStyleOptions(polygon.style);
                  // function for getting location
                  polygon.getHierarachy = new Cesium.CallbackProperty(function(time, result) {
                      var hierarchy = [];
                      for (var i = 0; i &lt; polygon.coordinates.length; i++) {
                          var coordinate = polygon.coordinates[i];
                          hierarchy.push(Cesium.Cartesian3.fromDegrees(coordinate.longitude, coordinate.latitude, coordinate.altitude));
                      }
                      return hierarchy;
                  }, false);
  
                  polOpts.hierarchy = polygon.getHierarachy;
  
                  p = mapContext.entities.add({
                      name: polygon.name,
                      polygon: polOpts
                  });
              }
              return p;
          };
  </code></pre>
  
  <p>If I add a single entity, it seems to work great. As I add more there is a delay (1-3 seconds) and then all entities do not update nicely. It looks really bad. </p>
  
  <p>Is there a way to limit the number of times this updates the entities. I have been reading the Cesium documentation, but cannot find anything on this. </p>
  
  <p>Or is there a better way to dynamically and consistently update entities? </p>