Four steps
- The NDVI series gives leaf area, by inverting Beer–Lambert
- Leaf area gives plant age, against the known growth of 24 species
- Age drives the growth itself
- The stand is lit by the hourly sun of its own location, with cast shadows and the light colour of that sky
The reading at the end is the fraction of light the canopy intercepts.
Two ways to build a plant
With the optional 3D package installed, plants are grown organ by organ from the species' own architecture and then voxelised. Without it, the canopy is built from analytic ellipsoid crowns of the same leaf area, which needs nothing beyond numpy.
!Current constraints
- The sun comes from a one-degree NASA POWER cell, so an area smaller than that is lit by its region's sun rather than its own.