Stopping CZML data interpolation

CesiumJS
1

Hello!

A very quick question regarding interpolation in CZML file data (well, interpolation in Cesium in general).

When using captured positioning data, if one drives the animation Timer to a moment well before or well after the end of data availability for a given object, the object’s position gets interpolated accordingly and, as expected, goes berserk.

This would not be a problem if all dynamic objects would have the same start and stop moments in the dataset (one would simply limit the viewable timeline) - only they don’t.

Is there a CZML property I can set with the specific interval an interpolation should be applied (or, the other way around, should NOT be applied? anything goes).

Many thanks!

2

Hugo,

If you simply want to set a single interval of availability for the object (i.e. the object “exists” for that interval and does not exist anywhere else) then you can use the “availability” property, which is an ISO8601 time interval.

An example would be:

{

“id”:“myObject”,

“availability”:“2010-11-12T17:00:00Z/2010-11-13T05:00:00Z”,

}

If you want the object to move, stop and stay in the same position for a while, then start moving again, you want to composite several position intervals together. You simple specify these intervals in the CZML file itself.

Something like the below:

“position”:{

“interval”:“2010-11-13T04:00:00Z/2010-11-13T05:00:00Z”,

“epoch”:“2010-11-13T04:00:00Z”,

“cartesian”:[t, x, y, z, t, x, y, z, t, x, y, z…]

},

“position”:{

“interval”:“2010-11-13T05:00:00Z/2010-11-13T06:00:00Z”,

“cartesian”:[x,y,z]

},

“position”:{

“interval”:“2010-11-13T06:00:00Z/2010-11-13T07:00:00Z”,

“epoch”:“2012-08-04T16:00:00Z”,

“cartesian”:[t, x, y, z, t, x, y, z, t, x, y, z…]

}

So the first interval is sampled, and then the second interval has a single position for the next hour, the third interval starts it moving again. I wrote the above off the top of my head, so you may need to check it against the full CZML syntaxt to make sure I got it correct.

3

Matthew,

Thank you so much. I can’t believe we actually have by now quite a complex CZML generator but never ended up generated multiple position intervals :slight_smile: actually, the thought hadn’t crossed my mind.

That will certainly solve it. If not, I’ll come back nagging if you don’t mind.

Thank you again,