Get the bounds [start, end) for all points at a certain height.
dm - The
height - The requested height
start - The first point at this height
end - One beyond the last point at this height
Height indexing is related to topological codimension. Height stratum 0 contains the highest topological dimension
points, often called “cells” or “elements”. If the mesh is “interpolated” (see
DMPlexInterpolate()), then height
stratum 1 contains the boundary of these “cells”, often called “faces” or “facets”.