Cesium World Terrain coordinate reference system?

I am using Cesium World Terrain as my basemap on a level in Unreal Engine. I need to understand the full coordinate reference system in order to place shapefiles on a sublevel and have them align.

I understand that the coordinate reference system is WGS84, but what is the EPSG value?

Hi @jill,

With Cesium for Unreal you can access two different coordinate systems, Geographic (Longitude, Latitude, Height, which is EPSG:4979) and ECEF(x, y, z, EPSG:4978).
The Unreal world coordinate system doesn’t follow any global coordinate system, but you can convert between UE coordinates, EPSG:4979, and EPSG:4978 with the methods found on CesiumGeoreference. If you’re trying to load a shapefile, you’d probably want to transform the coordinates of the shapefile to EPSG:4979, then convert them to UE coordinates for placement.

This tool may also be of use.

-Alex

That’s a nice conversion tool. I’ll be using QGIS to do the conversion between the shapefile CRS and EPSG:4979. I’m glad I asked because for some reason I thought Cesium used EPSG: 4326.

If I’m using Cesium for Unreal, does it make sense for me to just place the shapefile in Unreal Engine using its coordinates? My assumption is that it will not drape over the Cesium Ion terrain. What is the current technique to place shapefiles in Unreal when using Cesium Ion terrain, and have the shapefiles retain their data?

Jill