Milford Sound (NZMF) Terrain Anomaly: Vertical Wall and Elevation Offset

CesiumJS
1

Hi Cesium team,

I’m seeing a terrain anomaly around Milford Sound Airport (NZMF) when using Cesium World Terrain. The terrain in this area appears to be vertically offset by roughly 200 meters, which produces two visible effects:

  • The fjord water surface is rendered about 200 meters higher than its real elevation.

  • The surrounding terrain forms an artificial vertical wall around the airport and valley floor.

This makes the entire Milford Sound basin appear lifted upward, with the airport sitting at the bottom of a sheer drop.

Here is a minimal Sandcastle reproducer showing the issue.

The issue is visible even without vertical exaggeration; exaggeration only makes the artifact easier to see. I can provide additional camera positions or screenshots if helpful.

Thanks for taking a look.

2

Hey @Ricardo_Morin ,

Thanks for that, I’ll report this to the team and see if we can get it resolved! Unfortunately I can’t give you a timeline on this though. Is this stopping you from achieving something? Or did you just happen to notice it?

4

Hi @darcyvdd,

I noticed the issue because I happen to have a GPS track on my site in that particular area: RikiTraki

Since I am sampling the terrain to build the elevation profile, you can see how it is completely distorted.

Thank you for your attention.

Ricardo