[创意编码p5]魔法水环

https://www.openprocessing.org/sketch/989004

圆的参数方程

x= radius * sin(i)
y= radius * cos(i)

椭圆的参数方程

x= radius * sin(i)
y= radius-90*cos(i);

画一个底盘的椭圆

 function setup() {
    createCanvas(600, 600);
    // 设为 度数
    angleMode(DEGREES)
    stroke("#f4f1de");
    background(51);
    let radius = 200; //半径
    for (let i = 0; i < 360; i += 1) {
      let ex = radius * sin(i);  
      let ey = radius-90 * cos(i);

        ellipse(ex,ey,random(1,6))
    }
  }

现在我们开始编写点向上移动,造成一个有魔方氛围的感觉

let ude=[];

  function setup() {
    createCanvas(600, 600);
    // 设为 度数
    angleMode(DEGREES)

    let radius = 200; //半径
    for (let i = 0; i < 360; i += 1) {
      let ex = radius * sin(i);  //1 => -1 =>1
      let ey = radius-90 * cos(i);//
      ude[i] = new Ude(ex, ey);
    }
  }

  function draw() {
    background(51);
    stroke("#f4f1de");
    translate(width/2,height/2);

    for (let i = 0,len = ude.length; i < len; i += 1) {
      ude[i].update();
      ude[i].show();
    }
  }
  class Ude{
    constructor(ex,ey){
      // 当前向量
      this.pos = createVector(ex, ey);
      // 移动的向量
      this.acc = createVector(0,-0.01);
      // 算出差值的向量
      this.vel = createVector(0, 0);
      // limit 限制速度
      this.topspeed = 1;
      // 随机的小椭圆直径
      this.ellipsesize = random(1,6);
    }
    update(){

      // y -0.01 * 向量random(2) 限制速度1 ,
      // 最后的值加上差值
      this.acc.mult(random(2));
      this.vel.add(this.acc);
      this.vel.limit(this.topspeed);
      this.pos.add(this.vel)
    }
    show(){
      ellipse(this.pos.x, this.pos.y, this.ellipsesize)
      noStroke();
    }
  }