雰囲気のあるサークル・パッキングを作るテクニック

const w = 640;
const h = 640;
const num = 2000; // 試行回数

function setup() {
  createCanvas(w, h);

  // サークル・パッキング
  const circles = getRandomCircles(num, w * 0.4, h * 0.4);

  // 描画
  translate(w * 0.5, h * 0.5);
  background(100);
  circles.forEach((c) => circle(c.x, c.y, c.z));
}

function getRandomCircles(_num, _w, _h) {
  let circles = [];
  for (let i = 0; i < _num; i++) {
    let x = random(-1, 1) * _w;
    let y = random(-1, 1) * _h;
    let z = random(10, 50); // z軸の値を円の大きさとして使用
    if (circles.every((c) => dist(x, y, c.x, c.y) > (z + c.z) * 0.5)) {
      circles.push(createVector(x, y, z));
    }
  }
  return circles;
}

const w = 570;
const h = 570;

function setup() {
  createCanvas(w, h);
  translate(w * 0.5, h * 0.5);
  background(100);

  // サークル・パッキングと同時にノイズ・フィールド描画
  noFill();
  stroke(250);
  strokeWeight(3);
  const circles = getNoiseField(100, w * 0.4, h * 0.4, min(w, h) * 0.15, 5);

  // 円の描画
  fill(250);
  stroke(0);
  strokeWeight(1);
  circles.forEach((c) => {
    circle(c.x, c.y, c.z);
    if (c.z > 10) {
      circle(c.x, c.y, c.z * 0.5);
    }
  });
}

function getNoiseField(_num, _w, _h, _iDiv, _step) {
  const circles = [];
  for (let iX = -_w; iX < _w; iX += _iDiv) {
    for (let iY = -_h; iY < _h; iY += _iDiv) {
      let x = iX;
      let y = iY;
      beginShape();
      for (let i = 0; i < _num; i++) {
        let nVal = noise(x * 0.001, y * 0.001) * 2;
        x += _step * cos(nVal * TWO_PI);
        y += _step * sin(nVal * TWO_PI);
        vertex(x, y);
        let z = random(_step, _step * 5);
        if (circles.every((c) => dist(x, y, c.x, c.y) > (z + c.z) * 0.5)) {
          circles.push(createVector(x, y, z));
        }
      }
      endShape();
    }
  }
  return circles;
}

/*
Copyright (C) 2021- deconbatch

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>
*/