I am trying to find out how to plot a curve (or a more general area) on the surface of an object illustrated by
Assume for example I plot a sphere
and I now want to add an illustration of all points that are on the sphere plus satisfy a further condition (such as
y = 0 or even
y>0). Does somebody know a way to do this?
I want to apply this to a slighty more complicated situation, so a general answer that doesn't depend on the exact type of geometry would be best!