An error occurred while showing camera furstum planes

I had some problems when I wanted to showing camera furstum planes.

I use Cesium Inspector to show camera furstum planes. Most of time it works normal, but sometimes it’s wrong. As the following picture:


In addition, there are problems with the frustum display. camera position:

camera.setView({destination:Cesium.Cartesian3.fromDegrees(-89, 40, 2000000)});

“Show Frustum Planes”:

photo 1

Then I rotated the earth, so the longitude and latitude of camera was slightly different from the photo above, but height didn’t change, still was 2000000. As the following picture:

photo 2

In the photo 2, the camera frustum has a distinct near plane, however in the photo 1, the near plane looks like a point.

Why are two furstums so different when I just spin the earth? And why does an error occur sometimes when I pick “Show Frustum Planes”?

2. I want to show frustum because that I want to know if the plane in earth surface is intersect with camera frustum.

3. The Cesium version I’m using is 1.60, Chrome.