Centre in local [x, z]; null = the population's centre.
H3 resolution to colour (coarser = smoother); null = the data's own.
What to colour cells by.
Draw networks (needs the network argument).
Pixels per side.
Draw settlements as discs (farmsteads as single pixels).
Edge length of the mapped square, metres; null = the region's diameter.
Settings for renderPopulationMap.