No culling of tiles on the other side of the globe

Hello I wonder how fog culling should prevent rendering tiles from the other side of the globe - it appears not to work here.
From Tileset.cpp:
```
// CesiumJS will also fade out the fog based on the camera angle,
// so when we're looking straight down there's no fog. This is unfortunate
// because it prevents the fog culling from being used in place of horizon
// culling. Horizon culling is the only thing in CesiumJS that prevents
// tiles on the back side of the globe from being rendered.
// Since we're not actually _rendering_ the fog in cesium-native (that's on
// the renderer), we don't need to worry about the fog making the globe
// looked washed out in straight down views. So here we don't fade by
// angle at all.
```
Is there a plan to implement horizon culling for cesium-native?
The cesium updateView is frozen to zoom out without affecting the current tileset in this screenshot.