Inquiries about addImageryProvider

I recently started a 3D map test using cesium. I created imagerylayer using WebMapServiceImageryProvider and succeeded in applying it to 3D map.
but, Instead of one loaded image being uploaded to the 3D map, multiple images were found to cover the 3D map.
Attached is the result image
Please tell me what I should do.

Hi. I think you can try to limit the area with Rectangle. And also, I think your wms layer is incorrectly formed.