What reprojecting from Mollweide to Mercator does, drawn on the Mollweide plane
Every dot is a point of the source picture, sized by the angular deformation the reprojection itself applies there — not the deformation of either projection against the sphere, but of the map that carries one plane to the other. It reaches 116.5° here. This is the quantity a reprojection actually costs a shape, and it is computed from the two Jacobians alone: the sphere's own metric cancels exactly, so the transformation does not depend on the shape of the Earth at all. Drawn on the source plane, in Mollweide.
It is drawn by operation-figure with
show: "reprojection" — one member of a family of
14 figures
that share a generator, so the drawing above is what that generator returns when it is asked
for this one and given nothing else.
1 essay calls it. Every call below passes it something, because a placement that passes nothing draws whichever member of the family the generator happens to default to rather than the one its essay argues about.
Where it is called
Changing this changes every one of these figures.
