3D Model sometimes disappears

Hello, I can't reproduce this inside the sandcastle, but I am hoping to get some insight into what may cause this issue. I have an EntityCollection that has an entity. This entity has a model, billboard, and point specified. However, each of these have their properties set using TimeIntervalCollectionProperty. In other words, depending on some internal logic, the entity sometimes is shown as a billboard and sometimes is shown as a 3d model. The pointGraphic is in case the billboard fails to load. I use intervals on the "show" properties to turn on/off the model/billboard/point when the other is turned on.

I also have the position property set using the sampledPositionProperty so that it will interpolate.

I also have the historical path visible so that we can see where it is.

This is all working great. However, sometimes the 3d model just disappears. This is usually in the middle of the path, say starting 1/3 of the way from seattle to china and reappears at 2/3 of the way. However, if I zoom out, it shows up for more of the path.

I would like to add images but can't figure out how. I will see if I can reply from my email with images.

PleInitially, the airplane is shown


A little further, it is hidden


This is the same as the previous image, except I zoomed out and airplane came back


Please note that I have stepped through the code to where it is setting all of the properties from the timeIntervalCollectionProperty.getValue function, and it is indeed setting the properties correctly (show, scale, uri, etc.), it just is not showing up. The altitude is set by sampling the terrain. I have also tried with forcing it at altitude (in carto) as 0, 5000, and 50000.



Hi Joy,

I can reproduce your behavior if I have very few points describing the aircraft route, say one point near Seattle and a second near Kodiak, Alaska. The line and the point are being “drawn” above the surface of the earth but the interpolated position of the aircraft is below the surface and thus hidden. Adding more points in between solved the problem.

I hope that helps.


Ah, I think that should help. Thank you for

such a quick response .