1. A concise explanation of the problem you’re experiencing.
When using a callback property for positions on a PolyLineGraphic, framerate drops to 0 if PolyLineGraphic is clamped to ground.
2. A minimal code example. If you’ve found a bug, this helps us reproduce and repair it.
Here is a demo on Sandcastle
3. Context. Why do you need to do this? We might know a better way to accomplish your goal.
I need to use the callback to dynamically update a billboard and the polylines associated with it on the same render (they need to move in-sync and this doesn’t work if I update the positions statically…the billboard moves and then the lines move on a later render frame). I also need to do this with elevation data and the lines are clamped to ground.
4. The Cesium version you’re using, your operating system and browser.
1.52 (and before)
Chrome Version 70.0.3538.110 (Official Build) (64-bit)
Firefox 64.0 (64-bit)