viewer.flyTo( PathGraphics entity ) does not work?

[Willem van der Gugten]

Hello Cesium,

In our application we want to viewer.flyTo([],..) a line (plus a glTF model, but that is outside the scope now). The line is a PathGraphics because it is updated in real time.

For some reason this does not seem to work. Flying to e.g. a PolylineGraphics does work.

Any idea what is wrong? I tested in 1.16 and 1.17.

Thanks, Willem

Sandcastle:

var viewer = new Cesium.Viewer('cesiumContainer');

var sampledPositions = new Cesium.SampledPositionProperty();

sampledPositions.setInterpolationOptions({

interpolationDegree: 2,

interpolationAlgorithm: Cesium.LinearApproximation

});

sampledPositions.forwardExtrapolationType = Cesium.ExtrapolationType.HOLD;

sampledPositions.forwardExtrapolationDuration = 0;

var jsonTimedPoints = '[{"TimeStampUTC":"2015-09-20T14:53:26.0000000Z", "Latitude":20.0, "Longitude":7.0}, {"TimeStampUTC":"2015-10-20T14:53:26.0000000Z", "Latitude":44.0, "Longitude":8.0}]';

var latLonArrayDegrees = JSON.parse(jsonTimedPoints);

var scratchC3 = new Cesium.Cartesian3();

for (var idx = 0; idx < latLonArrayDegrees.length; idx++) {

    var timedPoint = latLonArrayDegrees[idx]; // array with timestamp, latitude and longitude.

    sampledPositions.addSample(Cesium.JulianDate.fromIso8601(timedPoint['TimeStampUTC']), Cesium.Cartesian3.fromDegrees(timedPoint['Longitude'], timedPoint['Latitude'], 0.0, undefined, scratchC3));

}

var entity1 = viewer.entities.add({

id: 'TestLine-1',

path: { // this is a PathGraphics

        material: new Cesium.Color(1, 0, 0, 1),

        leadTime: 0,

        trailTime: 365*24*60*60,

        show: true,

        width: 4

    },

    position: sampledPositions

});

var entity2 = viewer.entities.add({

id: 'TestLine-2',

polyline: {

        positions: Cesium.Cartesian3.fromDegreesArray([-35, 12, -4, 22, -8, 25]),

        material: new Cesium.Color(0, 1, 0, 1),

        show: true,

        followSurface: true,

        width: 4

    },

});

function flyToPathGraphics() {

    Sandcastle.declare(flyToPathGraphics);

    var promise = viewer.flyTo([entity1], {duration:10 });

    promise.then(function (result) {

            console.log('result=' + result);

        }).otherwise(function (error) {

            console.log('error=' + error);

    });

}

function flyToPolyLine() {

    Sandcastle.declare(flyToPolyLine);

    var promise = viewer.flyTo([entity2], {duration:10 });

    promise.then(function (result) {

            console.log('result=' + result);

        }).otherwise(function (error) {

            console.log('error=' + error);

    });

}

Sandcastle.addToolbarMenu([{

    text : 'fly here:',

    onselect : function() {

    }

}, {

    text : 'FLY path',

    onselect : function() {

        flyToPathGraphics();

        Sandcastle.highlight(flyToPathGraphics);

    }

}, {

    text : 'FLY poly',

    onselect : function() {

        flyToPolyLine();

        Sandcastle.highlight(flyToPolyLine);

    }

}]);