Issue on visualising terrain on cesium base map

Cesium ion
1

I have one DEM(.tiff) file having a 12.5-meter ground resolution with EPSG:4326 projections. After converting this DEM to a terrain format (which includes a layer.json file with 1 to 15 folders and .terrain files init), I made a zip out of it. So that I could visualize elevation(terrain) on the base map.

For the visualization, I followed the settings outlined in the “add_data_screen”, as shown in the screenshot below:

add_data_screen
add_data_screen1898×522 39 KB

However, when I upload the zip file to Cesium, I encounter the following error:

error
error658×298 16.3 KB

In addition to the standard upload method, I also tried an alternative approach by selecting “Cesium World Terrain” during the upload, but the error persists.

can anyone please help me understand why this error occurs and suggest how I can resolve it?

2

It sounds like you may be using a format which is not supported by Cesium ion. The ZIP file uploaded to Cesium ion must contain one of the supported formats.

The easiest way to upload DEM terrain to Cesium ion would be to just upload the TIFF file directly. Was there a reason why you needed to convert it before uploading?

Please let us know if uploading the DEM TIFF file directly to Cesium ion resolves your issue.

3

Uploading a direct DEM (.tiff) file resolved my issue, but I would like to understand why the following resources recommend converting the DEM(.tiff) file into the terrain(.terrain) format. I used the 2nd approach for visualization:

  1. This blog post
  2. The Cesium Terrain Builder Docker GitHub page

Could anyone provide further clarification on the advantages of converting to the .terrain format over using the DEM file directly?

4

Hi,

Neither of those links are for official Cesium content so I can’t speak to the motivations of the authors.

To clarify are you referring to the .terraindb format? Cesium does not support a .terrain format only .terraindb. The main difference between a .terraindb and a TIFF. would be where the tiling of the data happpens. When you upload a TIFF, Cesium ion does the tiling and handles any coordinate system reprojections. A terraindb upload is a file that already has had that processing done. Cesium ion is not doing any tiling in that case, just hosting the tiled data.