In post processing shader,how get point's height from earth surfac

1. A concise explanation of the problem you're experiencing.

In post precessing shader, have any glsl function like "Cesium.Ellipsoid.cartographicToCartesian" function,cover point from world coordinates to longitude, latitude, and height?
I want to know a point's height from earth surface.

thanks

Hi! Perhaps Cesium.sampleTerrainMostDetailed is what you’re looking for?