Entity path not showing

CesiumJS
1

Hi,

I’m new to Cesium, company project needs to show multiple satellites and their path.

I tried following code, it show satellite images, but path can’t display, here is the code:

// Compute entity

var entity = new Cesium.Entity({id: sId});

// Availability
entity.availability = new Cesium.TimeIntervalCollection([
    new Cesium.TimeInterval({
        start: Cesium.JulianDate.fromIso8601("2012-03-15T10:00:00Z"),
        stop: Cesium.JulianDate.fromIso8601("2012-03-16T02:40:00Z")
    })]);

// Billboard
entity.billboard = new Cesium.BillboardGraphics();
entity.billboard.image = "/image/satellite.png";
entity.billboard.show = true;

// Position
entity.position = positions;
entity.orientation = new Cesium.VelocityOrientationProperty(positions);

var fadedLine = new Cesium.StripeMaterialProperty({
    evenColor: Cesium.Color.YELLOW,
    oddColor: Cesium.Color.BLACK,
    repeat: 1,
    offset: 0.2,
    orientation: Cesium.StripeOrientation.VERTICAL
});

var path = new Cesium.PathGraphics();
path.material = fadedLine;
path.leadTime = new Cesium.ConstantProperty(0);
path.trailTime = new Cesium.ConstantProperty(3600 * 4);

entity.path = path;

// // Path
// entity.path = new Cesium.PathGraphics({
//     resolution: 1200,
//
//     material: new Cesium.PolylineGlowMaterialProperty({
//                     glowPower: 0.16,
//                     color: Cesium.Color.RED
//                 }),
//     width: new Cesium.ConstantProperty(10),
//     leadTime: new Cesium.ConstantProperty(1e10),
//     trailTime: new Cesium.ConstantProperty(1e10)
// });

// Make a smooth path
entity.position.setInterpolationOptions({
    interpolationDegree : 5,
    interpolationAlgorithm : Cesium.LagrangePolynomialApproximation
});

entityCollection.add(entity);

Above is piece of code to add entity into view.entities.

I tried PolylineGlowMaterialProperty and StripeMaterialProperty, both not showing path.

I also tried Availability time range and leadTIme+trailTime, not working.

Also, when I add Availability time range and leadTime+trailTime, got "array length " exception.

Anyone can help.

Thanks,

John

2

Forgot to mention the version, I use Cesium.js v 1.35, the latest version.

Thanks,

John

3

Anyone can help?

Thanks,

John

4

Hi there,

It looks like you had a problem with the alignment of your time intervals (the availability, and the timeline range. Here’s a working code example: http://cesiumjs.org/Cesium/Apps/Sandcastle/?src=Hello%20World.html&label=Showcases&gist=f1c951ba20dc310b38371cab34648abe

Hope that helps,

  • Rachel
5

Thanks, Rachel.

It works now, I switch coordinate generateor from Cesium.Cartesian3 to Cesium.Cartesian3.FromDegree, and the coordinate format accordingly, not sure it’s bug or not.

Thanks,

John

6

Hi John,

Sorry, what do you mean? If you still have a bug I would check your conversions.

Best,

  • Rachel