1. A concise explanation of the problem you’re experiencing.
The scope of the visual field can only be seen from some perspectives. In most cases, can’t anyone see it?
2. A minimal code example. If you’ve found a bug, this helps us reproduce and repair it.
https://drive.google.com/open?id=1GYzvMJVugo9wDW2x2yaXbS0yXSVn29f9
3. Context. Why do you need to do this? We might know a better way to accomplish your goal.
4. The Cesium version you’re using, your operating system and browser.
Chrome
77.0.3865.90 （64 ）
Cesium 1.62;