Polygon's positions's height change after a time

I create a polygon clamped to terrain by setting perPositionHeight attribute to false
and polygon’s hierarchy is a Cesium.CallbackProperty
when 5 seconds later
the polygon’s positions height changed to 0
is this a bug?


Thank you for bringing this to the community! From my understanding, this behavior seems reasonable. Given that you are clamping the polygon to the terrain, the height should match that of the terrain. This means that in some cases the height will be 0. Let me know if you have any other questions or concerns!