I am exploring terrain options for my app and trying to get “hello world” for custom terrain to work. While I think the terrain tiles are successfully being served and accessed, it looks like Cesium is only requesting up to the third zoom layer when I pan/zoom on the map. Here is what I have done:
Created terrain tiles using Cesium Terrain Builder. For terrain data, I downloaded GeoTiff files for GTOPO30 dataset from USGS. The result is a folder structure that supports 9 levels of zoom.
I created a basic layer.json file at the tile root folder:
Used Cesium Terrain Server to serve tiles on localhost.
In Cesium app, created new ProviderViewModel with URL to localhost location and added to default list of terrain providers.
Looking at the server output, I see tiles being requested for levels 1, 2, and 3. For example:
[06/Jun/2017:11:09:34 -0400] “GET /tilesets/test/2/0/0.terrain HTTP/1.1”
However, no higher levels are requested when I zoom into an area. The terrain is flat and looks the same to me as using Ellipsoid. There are no errors or output in console.
I verified that I can use sampleTerrain at the higher zoom levels. For example, I tried it at level 9 and it successfully gave a correct answer. So it seems Cesium only thinks there are 3 levels of terrain for the map? Any help on what’s going on or how to make this work? I am on Cesium 1.27 right now.