In the latest Cesium v 1.29.0 there are holes in the tiles where previously there weren't

@Kevin_Ring any chance? We opened this 21 days ago… thanks so much for taking a look, we’re waiting patiently to see if you find anything

I tried out your project. And it seems to me the tileset it is using is very broken.

First, the geometry at different levels of detail seems to be at completely different altitudes. So as you zoom in and out, the surface shifts up and down. And if the different LODs are displayed next to each other, then there are huge gaps between them caused by the different heights.

Second, the bounding volumes are incorrect. It looks like in some cases when the content mysteriously shifts upward, the bounding volumes do not. So it may be fairer to say the content is wrong and the bounding volumes are right. Either way, when the bounding volumes don’t match the content, the tile selection algorithm can’t possibly work right. It may decide a tile isn’t visible (because its bounding volume isn’t visible), when really the content is visible and not rendering it will cause a hole.

I’ve confirmed the above by looking at this tileset in CesiumJS, in addition to Cesium for Unreal. So I’m fairly confident it’s a bug in the tileset rather than a bug in Cesium for Unreal, because it’s unlikely that these two unrelated rendering engines would both have the same bug. You can try it out yourself in CesiumJS Sandcastle. I obviously didn’t want to include your tileset URL in this public post, so visit this link and then replace the text put your tileset.json URL here with the full URL of your tileset.json and click Run.