How to have animation along polyline with different location coordinates?

CesiumJS
1

Hi everyone,

In need of urgent help!

I wish to have some kind of animation along the polyline that I've created - Something similar to the example that Hannah has provided (Refer below):

var startLongitude = -75;
var endLongitude = -125;
var latitude = 43;
viewer.entities.add({
    polyline : {
        positions : Cesium.Cartesian3.fromDegreesArray([startLongitude, latitude,
                                                               endLongitude, latitude]),
        width : 10,
        material : new Cesium.PolylineArrowMaterialProperty(Cesium.Color.PURPLE)
    }
});

var geodesic = new Cesium.EllipsoidGeodesic(Cesium.Cartographic.fromDegrees(startLongitude, latitude), Cesium.Cartographic.fromDegrees(endLongitude, latitude));
var value = 0;
var cartographicPosition = new Cesium.Cartographic();
var point = viewer.entities.add({
    position: new Cesium.CallbackProperty(function(){
        var cartographic = geodesic.interpolateUsingFraction(value, cartographicPosition);
        var position = Cesium.Cartesian3.fromRadians(cartographic.longitude, cartographic.latitude);
        value = value > 1 ? 0 : value + 0.005;
        return position;
    }, false),
    point: {
        color : Cesium.Color.PURPLE,
        pixelSize : 20
    }
});

In the above example, only 1 latitude is being used throughout. However in my case, I have 2 different latitudes.

For instance:
Country A - Latitude: 47.0000, Longitude: 2.0000
Country B - Latitude: 38.8833, Longitude: 77.0167

I'm able to create a polyline, but i wish to have an animation along the polyline too. How do I go about doing it with the example above?

Thank you in advance!

Alan

2

Hello Alan,

This same method will work with different latitudes. Instead of using the same latitude with for both the start and end positions, use a [startLongitude, startLatitude, endLogitude, endLatitude] etc

Hope this helps!

-Hannah

3

Hi Hannah,

It is working now, thank you very much!

Alan