new/update CZML entity position

CesiumJS
1

Hello all,

I want to add and/or update entity positions (from czmlDataSource).

I have several czmlDataSources that are added to a dataSourceCollection ("Divisions", "Forts", etc which can be seen at www.geo-animate.com/CesiumScripts/battleForNormandy/animation.php).

I am using cartographicDegrees to control each entity via the position property.

1- If I want to add a new position to entity "123" of the "Divisions" czmlDataSource, do I simply process the new CZML position into the dataSourceCollection?

<<<<<<<<<
var newPosition =
  [ { "id" : "document", "version" : "1.0" },
  {
    "id" = "123",
    "position" : {
      "cartographicDegrees" : ["1944-06-06T06:00:00Z",5.000,5.000,0]
    }
  ];

var divisionsDataSource = new Cesium.CzmlDataSource.process(newPosition);
viewer.dataSources.add(dataSourceCollection.add(newPositionDataSource));

2- If I want to update an existing position to entity "123" of the "Divisions" czmlDataSource, must I remove the existing "123" entity and replace it entirely? Or can I process new positions with exactly the same timeStamp to overwrite the existing entity positions?

Best weekend, erik

2

Hello Erik,

Here is an example of how to get the entity from the CZML datasource and add a new position sample:

var czml = [{
“id” : “document”,
“name” : “box”,
“version” : “1.0”
}, {
“id” : “shape1”,
“name” : “Blue box”,
“availability”:“2012-08-04T16:00:00Z/2012-08-04T17:00:00Z”,
“position” : {
“cartographicDegrees” : [“2012-08-04T16:00:00Z”,-110.000, 35.000,0]
},
“box” : {
“dimensions” : {
“cartesian”: [400000.0, 300000.0, 500000.0]
},
“material” : {
“solidColor” : {
“color” : {
“rgba” : [0, 0, 255, 255]
}
}
}
}
}];

var viewer = new Cesium.Viewer(‘cesiumContainer’);
var dataSource = Cesium.CzmlDataSource.load(czml);
viewer.dataSources.add(dataSource);

dataSource.then(function(ds) {
var entity = ds.entities.getById(‘shape1’);
entity.position.addSample(Cesium.JulianDate.fromIso8601(‘2012-08-04T17:00:00Z’), Cesium.Cartesian3.fromDegrees(-117.000,20.000));
});

``

Best,

Hannah

3

Hey Hannah,

I am running some test with multiple aircraft coordinates and would like the air craft icons to position themselves in the direction they are heading.. The following snippet works for a single aircraft icon when I use the getById

  viewer.dataSources.add(Cesium.CzmlDataSource.load('../../data/simple.czml')).then(function(ds) {
        var entity = ds.entities.getById('Flight');
        //viewer.trackedEntity = entity;
        entity.orientation = new
Cesium.VelocityOrientationProperty(entity.position);
        entity.position.setInterpolationOptions({
        interpolationDegree : 5,
        interpolationAlgorithm : Cesium.HermitePolynomialApproximation
        });

where 'Flight' is the ID of a single aircraft in the CZML stream. I would like to do this for all/multiple flight icons, not just the specified getById.
  
Is this possible in either the JavaScript HTML or in the CZML data feed?

Thanks ahead for the support.

Shawn

4

You should be able to do this by looping through all the entities in your CZML and setting a velocity orientation property as you’ve done for that single entity. This Sandcastle has an example of looping through all the entities created from a dataSource and applying a color to them:

5

Thank you Omar, I will give this a try to see if it works.