Cesion Ion does not generate watermask for my uploaded DEM in GeoTIFF format

Cesium ion
1

Hello,

Cesion Ion does not generate watermask (nor bvh) for my uploaded DEM in GeoTIFF format.

Is it an expected behavior?

Thanks.

2

Can you elaborate on your issue? All assets uploaded as terrain always have watermask generated if the source indicates no-data over a water body. Have you turned on the watermark in CesiumJS to be sure? See Cesium Sandcastle.

3

Sure, I can elaborate:

The source is a custom source (GeoTIF) I uploaded via Cesium Ion.
I tried of course to enable the watermark option in Cesium for Unreal, in vain. Maybe I did it the wrong way.
Then I looked at the layer.json of my data source, which does not contain watermark in extensions.

4

Hi

Are you able to share the link from the “Open complete code example” from the Cesium ion Asset?

5

Sure I do (in DM because of access token)!

6

Thanks for sharing that.

The reason there is no watermask is because you did not select a base terrain (like Cesium World Terrain). When you upload a “regional” terrain raster and want the watermask to be turned on, anything that isn’t part of the terrain will also be considered water, and hence not the desired effect. Watermask is set based on the “no-data” or negative height values, and anything beyond the terrain you have uploaded will be considered as nodata automatically.

The way to solve this would be to upload the terrain and select CWT or other base terrain that has a water mask.

7

Thank you very much for that explanation!