A 3DTile data error at Longitude 180deg on Cesium Moon Terrain

Cesium for Unreal
1

Hello I’m a user of Cesium Moon Terrain on Unreal Engine, I used 3D tile data from Cesium ion and it works well on almost every aspects. Your imagery terrain data of moon is from the public LROC, DEM and DTM resolution attain near 100m. However when I uses it for my simulation work, there’s one problem. Near the moon site Longitude 179.6deg, there’s a mesh verteies wall that’s maybe 5000m tall. I give a screenshot showing the terrain currently looks like. The wall exist from Northpole to southpole, can be seen very far away, and it’s dinifite a mistake.

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2025-03-20 21 57 011920×1092 114 KB

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2025-03-20 21 57 101963×1116 382 KB

The overall wrong vertix wall looks like:

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2025-03-20 21 47 591734×1116 146 KB

I don’t know it’s error from Cesium ion or the Unreal engine, I think it’s may be from data, this’s a 3dtile source data error. because the imagery mosaic problem near the 180deg longitude, there maybe some very small digital error, but it effects a big mistake in 3D view.

As a user I can do nothing about the online Cesium3DTileset data, I can’t modify the mesh or to make something to hide it behind. As the data is online and can be downloaded or modified, I ask for your help.

2

Just as an attempt to narrow it down: Is this also present when looking at the Moon in Cesium Sandcastle ? (I couldn’t find it quickly, but may just not have been able to zoom to the right place…)

3

Because I’m very close to ground, I can see it . But from above you can’t see. You can try to add the following lines:

const pointsOfInterest = [
  {text: "CE4",
  latitude: -45.4446,
   longitude: 179.6,
  },  
];

const change4= {
  destination: new Cesium.Cartesian3(
  -1222421.8567435232, 42687.91188101505, -1242298.718640149,
  ),
  orientation: {
    direction: new Cesium.Cartesian3(
    0.07189853382507844, -0.9935994426514357, 0.08712490112797958,
    ),
    up: new Cesium.Cartesian3(
    -0.7011711923503058, 0.02448543758231906, -0.7125723979810423,
    ),
  },
  easingFunction: Cesium.EasingFunction.LINEAR_NONE,
};

const options1 = [
  {
    text: "Fly to...",
    onselect: () => {},
  },
  {
    text: "嫦娥四号",
    onselect: () => {
      removeRotation();
      scene.camera.flyTo(change4);
      artemis3Source.show = false;
    },
  },
];
4

That indeed looks like an artifact in the source data. For those who are investigating this, here is a Sandcastle that directly zooms to a place where this “wall” is visible:

When zooming out, one can see that a different form of this “wall” appears for the lower LOD, and it seems to be present somewhat consistently along a long latitude range.

(It seems to mainly appear in “low” areas. A wild guess: Maybe it appears in areas where the actual terrain is lower than the theoretical ellipsoid height? It’s probably not exactly that, though…)

5

Thanks for sharing. We are looking into this issue along the seam of the tiles.