how can I set outside rect show grid

This is my demo
I want to set outside rect show grid like this

Hi @edgexie,

Thanks for your post and for being part of the Cesium community.

This is an interesting idea. You may be able to find a solution to implement this using the examples of plotting grid lines on the globe shown in this sandcastle example Cesium Sandcastle.

Please have a look and let us know if you have additional thoughts. Perhaps other community members will also have suggestions.

Thanks,
Luke