How to add trajectory orientation to CZML file - cesiumjs

Question

I have a czml file representing an aircraft flying a specified path. The file is constructed based on the Sancastle examples provided by Cesiusm (CZML Model + CZML Path).
Here is the CZML variable:
var czml = [{
"id" : "document",
"name" : "CZML Path",
"version" : "1.0",
"clock": {
"interval": "2012-08-04T10:00:00Z/2012-08-04T15:00:00Z",
"currentTime": "2012-08-04T10:00:00Z",
"multiplier": 10
}
}, {
"id" : "path",
"name" : "path with GPS flight data",
"description" : "<p>Hang gliding flight log data from Daniel H. Friedman.<br>Icon created by Larisa Skosyrska from the Noun Project</p>",
"availability" : "2012-08-04T10:00:00Z/2012-08-04T15:00:00Z",
"path" : {
"material" : {
"polylineOutline" : {
"color" : {
"rgba" : [255, 0, 255, 255]
},
"outlineColor" : {
"rgba" : [0, 255, 255, 255]
},
"outlineWidth" : 5
}
},
"width" : 8,
"leadTime" : 10,
"trailTime" : 1000,
"resolution" : 5
},
"model": {
"gltf" : "../../SampleData/models/CesiumAir/Cesium_Air.glb",
"scale" : 2.0,
"minimumPixelSize": 128
},
"position" : {
"epoch" : "2012-08-04T10:00:00Z",
"cartographicDegrees" : [
0,-122.93797,39.50935,1776,
10,-122.93822,39.50918,1773,
20,-122.9385,39.50883,1772,
30,-122.93855,39.50842,1770,
40,-122.93868,39.50792,1770,
50,-122.93877,39.50743,1767,
60,-122.93862,39.50697,1771,
70,-122.93828,39.50648,1765,
80,-122.93818,39.50608,1770,
90,-122.93783,39.5057,1754,
100,-122.93777,39.50513,1732,
110,-122.93793,39.50458,1727,
120,-122.93815,39.50415,1717,
130,-122.9382,39.50362,1713,
140,-122.93818,39.5031,1703,
150,-122.93812,39.50258,1706,
160,-122.93792,39.5022,1707,
170,-122.93775,39.50177,1698,
180,-122.93745,39.50125,1693,
190,-122.93723,39.50073,1694,
200,-122.9373,39.50023,1702
]
}
}];
In order to be able to run the the code I also add the following lines:
var terrainProvider = new Cesium.CesiumTerrainProvider({
url : 'https://assets.agi.com/stk-terrain/v1/tilesets/world/tiles',
requestVertexNormals : true
});
var viewer = new Cesium.Viewer('cesiumContainer', {
terrainProvider : terrainProvider,
baseLayerPicker : false
});
viewer.dataSources.add(Cesium.CzmlDataSource.load(czml)).then(function(ds) {
viewer.trackedEntity = ds.entities.getById('path');
});
If you run the code you can see how the center point of the aircraft follows the trajectory, however its heading is not aligned with it thus giving a wrong rap presentation of what the flight should look like:
Would you be able to explain how to add the aircraft orientation to the the code without possible changing the initial czml file structure?
Note: I have found the answer to this question but I was not able to implemented to my problem.

Answer 1

I came up with an answer to the my question. Here there are the lines of codes that if placed in Sandcastle will allow to load the czml file and then add the orientation property through some type of interpolation:
//Sandcastle_Begin
var terrainProvider = new Cesium.CesiumTerrainProvider({
url : 'https://assets.agi.com/stk-terrain/v1/tilesets/world/tiles',
requestVertexNormals : true
});
var viewer = new Cesium.Viewer('cesiumContainer', {
terrainProvider : terrainProvider,
baseLayerPicker : false
});
var options = {
camera : viewer.scene.camera,
canvas : viewer.scene.canvas
};
Sandcastle.addToolbarMenu([{
text : 'Lateral avoidance w. real Wx and waypoints (KJFK-LEBL)',
onselect : function() {
viewer.camera.flyHome(0);
viewer.dataSources.add(Cesium.CzmlDataSource.load('./SampleData/interp_turb_data_fromFede_avoid_realistic_w_waypoints.czml')).then(function(ds) {
var entity = ds.entities.getById('path');
// viewer.trackedEntity = entity;
entity.orientation = new Cesium.VelocityOrientationProperty(entity.position);
entity.position.setInterpolationOptions({
interpolationDegree : 1,
interpolationAlgorithm : Cesium.HermitePolynomialApproximation
});
});
}
}], 'toolbar');
Sandcastle.reset = function() {
viewer.dataSources.removeAll();
viewer.clock.clockRange = Cesium.ClockRange.UNBOUNDED;
viewer.clock.clockStep = Cesium.ClockStep.SYSTEM_CLOCK;
};
//Sandcastle_End
In this way the aircraft will be aligned with the trajectory!