[Unity] How to get terrain elevation from Cesium3DTileset to prevent objects rendering below ground

Cesium for Unity
1

Hi Cesium team,

I’m using Cesium for Unity (v1.16.1) with Unity Hub 3.8 to visualise 3D terrain using a Cesium3DTileset.

Problem

When placing objects using georeferenced coordinates (longitude, latitude, height), I often find that the objects are rendered below the terrain surface, especially when the height is close to ground level.

I would like to:

  • Sample the terrain elevation at a specific longitude and latitude
  • Adjust my object’s height so that it sits exactly on top of the terrain
  • Prevent rendering issues where the object appears buried underground

My Questions

  1. Is there a recommended way in Cesium for Unity to get terrain elevation at a specific location?
  2. Can I add colliders or otherwise access the terrain mesh height directly?
  3. What are the best practices for accurately placing objects on top of Cesium terrain?

Thanks for your support!

2

@deet_dev You’ll want to give SampleHeightMostDetailed a try. You can use it from a coroutine like:

// height is ignored
var task = tileset.SampleHeightMostDetailed(new double3(longitude, latitude, height));
yield return new WaitForTask(task);
CesiumSampleHeightResult result = task.Result;
if(result.sampleSuccess) {
    // result.longitudeLatitudeHeightPositions will contain the positions with heights sampled from the tileset
}