Nearby tiles disappear (above ground, under reference ellipsoid)

CesiumJS
1

You don’t have to visit Death Valley or the Dead Sea, there are many low level coastal areas under the reference ellipsoid that disappear when the camera is close. Is there a setting to change this behavior, perhaps to not disappear until say -100 meters or whatever?

2

Check out issue #2271 including a link to a partial workaround.

Patrick

3

Thanks for the info, I did look at

https://groups.google.com/forum/#!topic/cesium-dev/87rvANHNnjs

It mentions Line 414 of GlobeSurfaceTileProvider.js which on the current version of that file is a blank line, and there are if statements directly before and after. Judging by the context I’m going to guess it refers to this one

if (intersection === Intersect.OUTSIDE) {
return Visibility.NONE;}

However I’m not certain.

4

I think it should be Line 415 now:

if (frameState.mode === SceneMode.SCENE3D) {

We want to disable horizon culling, not view frustum culling (well, we could just disable the entire function).

Patrick

5

I tried the if statements directly before and directly after line 415 with no luck, both caused Cesium to crash.

I noticed that it isn’t always 0 height that causes tiles to disappear, I’ve discovered a particular tile that disappears at -5.77 meters (from camera._positionCartographic.height) I created a temporary unlisted video to demonstrate https://www.youtube.com/watch?v=wnDmuVY66dQ

6

Thanks for the video. I suspect this is, at least in part, a horizon culling issue. I’ll let you know when we look at it. No promises, but we are working on a near-ground demo so if this shows up, we may fix it soon.

Patrick

7

This issue was fixed and will be in the next release on October 1.

Dan