paper-polyomino-grammatical-evolution

Software artifacts for the experiments on the evolution of polyominoes guided by a 2-D grammar.

Paper

The paper related to these experiments is this one:

• Jessica Mégane, Eric Medvet, Nuno Lourenço et al. Exploring Grammar-Guided Design and Evolution of Polyominoes with Modular Soft Robots, 09 October 2025, PREPRINT (Version 1) available at Research Square

@article{megane2025exploring,
  title={Exploring Grammar-Guided Design and Evolution of Polyominoes with Modular Soft Robots},
  author={M{\'e}gane, Jessica and Medvet, Eric and Louren{\c{c}}o, Nuno and Machado, Penousal},
  year={2025}
}

How to reproduce the experiments

Requirements

• JDK 25

The binary of JGEA, the evolutionary framework these experiments are based on, is already available in this repo.

Evolution of polyominoes (as synthetic problems)

All five grammars on all five targets with GA (with the bits(500) representation):

java \
  -jar jgea.jar \
  -nt 16 -nr 4 \
  -f exp-files/synthetic-all-ga.txt \
  --expHeadLines \
    '$nOfEvals = 20000' \
    '$seeds = [1:1:50]'

Three grammars on two targets (dog and circle) with four EAs (with the reals(200) representation):

java \
  -jar jgea.jar \
  -nt 16 -nr 4 \
  -f exp-files/synthetic-circle+dog-eas.txt \
  --expHeadLines \
    '$nOfEvals = 20000' \
    '$seeds = [1:1:50]'

Evolution of VSRs

Two VSR grammars (biped and worm) for the locomotion problem with NSGA-II (with the bits(1024) representation):

java \
  -jar jgea-vsrs.jar \
  -nt 16 -nr 4 \
  -f exp-files/vsr.txt \
  --expHeadLines \
    '$nOfEvals = 20000' \
    '$seeds = [1:1:10]'

Overview of the results

Evolution of VSRs

Evolution of the velocity and power for the fastest robot

Sample videos of the final fastest robot

Videos from runs 1 to 8 (more in results/vsr.txt/).

With grid (no-grammar) representation

With biped-grammar representation

With worm-grammar representation

Objective plots

Plots from runs 1 to 5 (more in results/vsr.txt/).

With grid (no-grammar) representation

With biped-grammar representation

With worm-grammar representation

How to transform mp4 videos to gif

Within the video directory:

for i in {0001..0008}; do
    ffmpeg -i "v100-grammar-biped-$i.mp4" -vf "scale=150:-1:flags=lanczos" "v100-grammar-biped-$i.gif" -y
    ffmpeg -i "v100-grammar-worm-$i.mp4" -vf "scale=150:-1:flags=lanczos" "v100-grammar-worm-$i.gif" -y
    ffmpeg -i "v100-grid-$i.mp4" -vf "scale=150:-1:flags=lanczos" "v100-grid-$i.gif" -y
done