extruding coastlines in spherical domain

Hi, I’m plotting spherical data and adding coastlines from a separate file - looks great. I can also make the 3D surface deviate from a pure sphere based on my data and color that extruded surface with other variables. Also looks great. What I can’t figure out how to do is extrude my coastlines as well, so the map is plotting on top of the extruded surface. Is this possible?

(I can make the coastlines on a bigger sphere so they sit above the extruded surface but I can’t make them run along it.)


In case any else has the same question - I still haven’t managed to figure out how to extrude coastlines but it is possible to achieve a similar effect by texture mapping an image of a map onto the extruded surface.