Retrieving data from SampledProperty

CesiumJS
1

Hi,

Please would it be possible to have some advice on retrieving data from a SampledProperty?

First, I’m setting up the clock in the Cesium viewer to cover the period of time in which I am interested:

var start = Cesium.JulianDate.fromIso8601(‘2012-08-04T13:21:40Z’);

var stop = Cesium.JulianDate.fromIso8601(‘2012-08-04T19:08:09Z’);

//Make sure viewer is at the desired time.

viewer.clock.startTime = start.clone();

viewer.clock.stopTime = stop.clone();

viewer.clock.currentTime = start.clone();

viewer.clock.clockRange = Cesium.ClockRange.LOOP_STOP; //Loop at the end

viewer.clock.multiplier = 4;

viewer.timeline.zoomTo(start, stop);

``

This function loads two data points into the SampledProperty, with the intention of interpolating between the two extremes:

function paramHdg () {

var propertyx = new Cesium.SampledProperty(Number);

propertyx.addSample(Cesium.JulianDate.fromIso8601(‘2012-08-04T13:21:40Z’), 1.0);

propertyx.addSample(Cesium.JulianDate.fromIso8601(‘2012-08-04T19:08:09Z’), 100.0);

return propertyx;

}

``

The intention of this code is to get back tHdg from the above function and then retrieve an interpolated value (I’ve omitted any ‘vars’ because I was using them as globals during troubleshooting):

var tHdg = paramHdg();

viewer.clock.onTick.addEventListener(function(clock) {

  currentTime = clock.currentTime;

  hg = tHdg.getValue(currentTime);

                                  // Do something with hg

									  }

);

``

What have I missed, included or otherwise turned on its head?!

Thanks,

Hugh

(just starting to get to grips with Cesium)

2

The code you included looks correct. To get the value of any Property (such as SampledProperty) you call getValue and pass in a time, as you have done. What problem are you seeing?

3

Hello Scott,

It doesn’t appear to return any data. If I put the same data as the first item of a quartenion and use SampledPositionProperty it works perfectly.

4

I took the code you pasted above and made a Sandcastle example.

http://cesiumjs.org/Cesium/Apps/Sandcastle/?src=Hello%20World.html&label=Showcases&gist=8dea46ae90144f70a0bc807316eca1f1

You can see that the correctly interpolated heading value is logged to the console and the returned value changes as the current time changes.

5

Thanks, Scott.

I got rid of the function ‘paramHdg’ (left it as a straight list) and it started working. The problem must be somewhere else in the code.

Thanks again,

Hugh