Creating a flight animation

CesiumJS
1

Hi,

I’m trying to create a flight animation as per the Camera tutorial, but the call Cesium.CameraFlightPath.createAnimationCartographic() causes a TypeError in CameraFlightPath.js:553.

The error occurs in the follow bit of code, `projection’ is undefined so the getEllipsoid() call fails.

var projection = frameState.scene2D.projection;

if (frameState.mode === SceneMode.SCENE3D) {

var ellipsoid = projection.getEllipsoid();

My code is as follows. I am using Cesium build from the git repository rather than the b18 build.

“use strict”;

function flyToCoords( scene, coords ) {

console.log('scene: ’ + scene);

disableInput(scene); // function same as in Camera tutorial

var flight = Cesium.CameraFlightPath.createAnimationCartographic(scene.getFrameState(), {

destination : destination,

onComplete : function() {

enableInput(scene); // function same as in Camera tutorial

}

});

scene.getAnimations().add(flight);

}

// Display default Cesium globe.

var widget = new Cesium.Viewer(‘cesiumContainer’);

// Load GeoJSON file.

var url = ‘P5_part.json’;

//renderGeoJson(widget, url);

// fly to polygon from geojson

var destination = Cesium.Cartographic.fromDegrees(101.685901, 2.906312, 500.0);

flyToCoords(widget.scene, destination);

Cheers,

Brendan

2

This may be a bug, but I’m not positive. There are two things to try.

  1. Add the below right after you create the Viewer:

widget.resize();

widget.render();

My guess is that you are starting a flight before the first render every happens, exposing the bug.

If that doesn’t work, try adding the below code to the same spot.

widget.scene.scene2D.projection = new Cesium.WebMercatorProjection(Cesium.Ellipsoid.WGS84);

Let me know if either of these fixes it, or if it’s still broken.

3

The first option fixes it, I still get the same error with the second option.

Cheers,

Brendan

4

Good to know, I’ll file an issue.

5

The fix for this is now in master and will be released with b19 on Thursday.

See https://github.com/AnalyticalGraphicsInc/cesium/pull/986 for details.