Dynamic/Interpolated Polygon

1. A concise explanation of the problem you’re experiencing.

Would like to efficiently build czml that has a defined bounded polygon changing over time. As a path is interpolated, I would like to have a polygon interpolated as well. An example would be if you moved a flashlight across the floor, the light splash changes. It’s unclear how to both change the position of polygon and the shape of the polygon over time efficiently. Obviously, and ellipse with a certain semimajor/semiminor axis can move over time, but I need to be able to change the shape as well.

2. A minimal code example. If you’ve found a bug, this helps us reproduce and repair it.


3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

Trying to visualize a footprint of a sensor on the ground, which changes based on ephemeris/altitude. Can calculate the geospatial bounds of the footprint over time, but don’t know how to efficiently apply this to czml.

4. The Cesium version you’re using, your operating system and browser.

1.61, Windows 10, Firefox.

Time-dynamic polygons are defined in CZML by treating each vertex as a separate object (with its own definition of how it changes over time), then by constructing the polygon using references. See this Sandcastle: