Reinforcement learning · UCL Digital Studio · with Raghul Siva · 2024

Adaptive
façades.

A twisted tower, panelled and rationalised — then a PPO agent learns to open and fold its skin from a week of simulated sun.

Grasshopper · Python · Stable-Baselines3
Ladybug · Honeybee · Kangaroo · Galapagos

Performative Freeform Façades · report

01 · Form finding

Twist, taper, evaluate.

Galapagos searches twist, scale and count against a Ladybug radiation study.

Evolutionary solver exploring the form space

Form matrix

Form matrix

Optimisation results with radiation roses

Candidates with their radiation roses

02 · Panelisation

Thousands of panels, a handful of parts.

Hexagons where the surface is gentle, triangles where it isn’t; relaxed with Kangaroo, clustered with a Gaussian mixture model.

Three panelled towers

Three towers and their unrolled grids

Relaxation — Kangaroo settling the mesh

Panel rules

Rules — 4 m slabs, ~1.3 m hexagon

GMM clusters on the tower

GMM clusters mapped back

03 · Adaptive components

Eight ways to close a panel.

Folding experiments in Kangaroo. Each is a single-parameter action an agent can learn to drive.

01 Triangulated iris

02

03

04

05 Petal fold

06

07

08 Diamond fold

Three systems tracking the sun

Hexagonal, triangular and diamond systems on three towers

Three systems, three towers — hexagonal scaling, triangular folding, diamond folding

Section: hexagonal scaling

Section — hexagonal scaling

Section: triangular folding

Section — triangular folding

04 · Reinforcement learning

Learn the skin from a week of sun.

Observation: sun-vector radiation per panel. Action: scale factor. Reward: less radiation, less deployed surface. Trained with PPO on 1, 2, 4 and 8-day windows and tested on unseen days.

RL loop diagram

Training — one panel learning to close

Training — top view

Trained policy on the tower — apertures tracking the sun through a day

Results by training window

1 · 2 · 4 · 8 days of training

Hourly value chart

Hourly values — longer windows converge lower

RL vs parametric

RL policy vs parametric rule, same tower, same sun

Interactive

The rule the agent had to beat.

Aperture ∝ 1 − radiation. Move the sun around a curved tower face.

Sun-responsive hex façadeColour = incident radiation; dark opening = aperture.
Live · JS
sun radiation aperture