Phi Lab

Crown Shyness

Neighbouring trees stop just short of touching, leaving rivers of sky between their crowns. A pattern no single tree owns.

Thomas Yang @ Phi Lab Foundation · Fengchen Liu @ UC Berkeley

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Hold the dial yourself

This is the simulation itself, not a recording. Drag the die-back gauge and the stand answers; drag the timeline to replay the whole arc; switch stem density and watch the same rule at four scales. Every number is measured, per frame, with one fixed estimator.

evolving stand
die-back
0.000
MOVEMENT I die-back sweep
contact die-back rises 0 to 0.06
die-back fraction (dimensionless) 0.000
drag the handle: the stand re-renders as you move
stem density 81 stems
each density replays its growth, bare stems to equilibrium
median crown-edge clearance (m) +0.00 m
canopy cover (fraction of ground) 0.00
both series measured per frame with one fixed estimator
the full 34 s arc: drag anywhere on the curve

What is moving

Occupancy

A branch tip that reaches space a neighbour already fills stops where it is. Taller trees claim contested ground first, so every boundary remembers both crowns that shaped it.

Abrasion

Where crowns touch, the wind grinds the meeting tips away. The simulation retreats each contacting branch by a fixed fraction of its own length. That fraction is the dial in the film.

No gap is drawn

The channel width is set nowhere in the code. It is an equilibrium between growth pressure and contact loss, so it scales with the crowns themselves.

The stand, not the tree

Remove either neighbour and the channel between them vanishes. The pattern lives between trees, which is why it must be generated jointly or not at all.