Using vertex positions' references for polyline in CZML

CesiumJS
1

Hi guys!

I was inspired by your satellite tracking demo on Cesium site’s main page and decided to build our own tracker based on Cesium. Everything went good until visualizing satellite’s field of view.

First, I tried to use a pyramid in my CZML (as it’s done in your demo) but had no luck. I was expected that cartesian coordinates of satellite’s position would give me the rotation vector to build the orientation quaternion. But I was unable to orient the pyramid towards the Earth’s center this way. Probably, I don’t understand something about quaternions. Unfortunately, CZML wiki pages don’t give some useful information on this yet.

As the result, I decided to simplify field of view visualization by replacing the pyramid by polyline. I try to specify polyline’s vertexes using references property as they change in time. Positions for each polyline point are placed in satellite-27424, satellite-27424-sp1 and satellite-27424-sp2 packets. CZML below doesn’t work for me. Even satellite-27424 is not showing anymore. Could you please tell me what’s wrong with my vertexPositions property? Is it possible to determine somehow whether CZML is valid, and if not - what’s wrong exactly.

Thank you so much.

Please look at CZML sample in the attachment.

satellite.czml (5.85 KB)

2

I missed .position suffixes in references. So references should be

"vertexPositions": {

    "references": ["satellite-27424-sp1.position", "satellite-27424.position", "satellite-27424-sp2.position"]

}

instead of

"vertexPositions": {

    "references": ["satellite-27424-sp1", "satellite-27424", "satellite-27424-sp2"]

}

Thanks.