Gravity Effector
Gravity Effector is one direction, the same everywhere on the tree. It is the effector most trees start with, and it is easy to reason about because it doesn't change from point to point. See Shaping.
Add it from the effector picker on a Grow, Assembly Decoration or any other node with an effector stack (see Where effectors go), or from the Effectors button on the Natsura toolbar. It has no inputs to wire.
Settings
Gravity Direction points straight down by default, (0, -1, 0). The row's mode, Attract or Repel, sets which way along it growth moves, and the row's strength sets how much.
Name is the attribute this effector writes, the node's name by default.
Mapping its strength
A single strength bends every branch the same amount. If a new Gravity Effector pulls the tree upright when you want the branches to droop, flip the direction first. Then map the Grow row's strength from u with Self and each branch arcs along its length. Raise the map's output to strengthen it, and set one end of the output range negative to pull the branches up nearer the base.
To vary the arc from the bottom of the tree to the crown, see The arc changes up the tree. Mapping covers maps.
Status
Gravity Effector is experimental.
Create Graft Mesh
Create Graft Mesh turns an imported scan into the mesh procedural growth attaches to: it remeshes the scan, rounds off its open ends and thins the polygons towards them.
Grow
Grow adds a chain of internodes to a tree, with control over where it starts, its length, width, angles, forks, effectors and decorations. Trees are built by chaining Grows into a Simulate.