NZ7921 Milford Sound / Piopiotahi

The bathymetry data comes from depth area polygons that are the digital version of the depth contours shown on the chart. Using some data wizardry, I converted these polygons to a digital elevation model.

The topography data comes from a digital elevation model for the whole country, which I discretised into 200m intervals to match the height contours shown on the chart.

After combining the bathymetry and topography into a single elevation model, I cut out the section for the inset and ‘georeferenced’ it into the correct position on the chart, and masked out the area for the title block.

This frankenstein’s monster of an elevation model was then used as an image texture to displace a plane in Blender, and the original chart image was used to colour the plane.