How are skirts created for Cesium terrain tiles?

Are the skirts used for hiding tile cracks generated when the tiles are created, or are they created at runtime? Do the skirts go straight down, or do they angle slightly outwards?

In either case, I’d love to be pointed in the direction of the code for this. I want to understand how to make terrains with real time LOD updates without too much overhead, and Cesium seems to have solved that problem pretty cleanly!

I’d love to see if I can make some of my own tiles work on Cesium without cracks :slight_smile: