When I add a cylindrical solid to the scene, I notice that the part below the ground is still visible. Is there any way to display only the portion above the ground?
The way how it currently looks is strange. It looks like the cylinder is partially visible in some areas. This might be a bug, and may have to be investigated (or, first of all, confirmed as a bug) by someone from the CesiumJS core team.
However, the fix for now might just be to set
viewer.scene.globe.depthTestAgainstTerrain = true;
not strange.
It is very understandable.
You should enable “Depth Test”.
viewer.scene.globe.depthTestAgainstTerrain = true;