按下鼠标时的矢量吸引力

Question

目前正在尝试使用 createVector 函数在 3D 立方体上创建吸引力效果。景点设计为在按下鼠标时触发，但目前显示错误：

Uncaught TypeError: Cannot read property 'copy' of undefined

代码：

let cubes = [];

function setup() {
  createCanvas(windowWidth, windowHeight, WEBGL);
  backCol = color(243, 243, 243);
 
  for (let i = 0; i < 10; i++) {
    for (let j = 0; j < 10; j++) {
      let xPos = map(i, 0, 9, 50, width - 50);
      let yPos = map(j, 0, 9, 50, height - 50);
      cubes.push(new Cubes(xPos, yPos));
    }
  }
}

function draw() {
  background(backCol);
  noFill();
  for (let cube of cubes) {
    cube.update();
  } 
  attracting();
}

function attracting() {
  for (let a = 0; a < cubes.length; a++) {
    cubes[a].attraction(mouseX,mouseY);
  }
}

class Cubes {

  constructor(x, y) {
    this.x = x;
    this.y = y;
    this.size = 30;
    this.stroke = 70;
    this.gap = 150;
    this.shift1 = color(96);
    this.shift2 = color(244);
 
    //vector variables
    this.pos = createVector(x, y);
    this.vel = createVector(); 
    this.acc = createVector();
  }

  update() {
    this.shape();
    this.test_Color();
    
    //attraction values
    this.vel.add(this.acc);
    this.vel.limit(5);
    this.pos.add(this.vel);
    this.acc.mult(0);
  }
  
  shape() {
    push();
    stroke(this.stroke);
    this.test_Color();
    translate(this.x - width / 2, this.y - height / 2, 0);
    this.test_rotation()
    box(this.size);
    pop();
  }

  test_Color() {
    fill(this.shift1);
  }

  test_rotation() {               
    rotateX(frameCount / 60);
    rotateY(frameCount / 60);
  }
  
  attraction(target) {
    
    //all cubes supposed to attract towards the mouse when pressed

    if (mouseIsPressed) {
      let force = p5.Vector.sub(target.pos,this.pos);
      let d = force.mag();
      d = constrain(d, 1, 25);
      var G = 50;
      var strength = G / (d * d);
      force.setMag(strength);
      if (d < 20) {
        force.mult(10);
      }
      this.vel.add(force);  
    }
  }
}

不确定要进一步添加什么细节。不确定要进一步添加什么细节。不确定要进一步添加什么细节。不确定要进一步添加什么细节。不确定要进一步添加什么细节。不确定要进一步添加什么细节。不确定要进一步添加什么细节。

Answer 1

您正在使用索引 a 作为 Cubes.attraction 的参数，它需要一个具有 pos 向量场的对象（一个立方体？）
您正在尝试使用 this.x / this.y 来定位您的立方体，update 不会更改它们。使用 this.pos 向量代替
您可以通过检查是否只按下一次鼠标进行优化，然后仅在每个立方体上调用 attraction 并将鼠标坐标作为向量参数
在物理学中，力驱动加速度，而不是速度。我改变了那个，但也许这是你故意的。
您应该将 class 名称更改为 Cube 而不是 Cubes

let cubes = [];

function setup() {
  /* max(...) here is just for rendering with minimum size in the snippet */
  createCanvas(max(windowWidth, 800), max(windowHeight, 600), WEBGL);
  backCol = color(243, 243, 243);
 
  for (let i = 0; i < 10; i++) {
    for (let j = 0; j < 10; j++) {
      let xPos = map(i, 0, 9, 50, width - 50);
      let yPos = map(j, 0, 9, 50, height - 50);
      cubes.push(new Cubes(xPos, yPos));
    }
  }
}

function draw() {
  background(backCol);
  noFill();
  for (let cube of cubes) {
    cube.update();
  } 
  attracting();
}

function attracting() {
  /* changed to check for mouse pressed once for all cubes */
  if (mouseIsPressed) {
    /* generating mouse position vector once for all cubes */
    const mousePosVect = new p5.Vector(mouseX, mouseY);
    for (let a = 0; a < cubes.length; a++) {
      cubes[a].attraction(mousePosVect);
    }
  }
}

class Cubes {

  constructor(x, y) {
    /* Removed useless and confusing this.x, this.y */
    this.size = 30;
    this.stroke = 70;
    this.gap = 150;
    this.shift1 = color(96);
    this.shift2 = color(244);
 
    //vector variables
    this.pos = createVector(x, y);
    this.vel = createVector(); 
    this.acc = createVector();
  }

  update() {
    this.test_Color();
    
    //attraction values
    this.vel.add(this.acc);
    this.vel.limit(5);
    this.pos.add(this.vel);
    this.acc.mult(0);
    this.shape();
  }
  
  shape() {
    push();
    stroke(this.stroke);
    this.test_Color();
    /* Used this.pos instead of this.x, this.y for positioning */
    translate(this.pos.x - width / 2, this.pos.y - height / 2, 0);
    this.test_rotation();
    box(this.size);
    pop();
  }

  test_Color() {
    fill(this.shift1);
  }

  test_rotation() {               
    rotateX(frameCount / 60);
    rotateY(frameCount / 60);
  }
  
  attraction(targetVector) {
    //all cubes supposed to attract towards the mouse when pressed

    /* Set target argument to vector,
     * moved the `if (mouseIsPressed)` condition outside */
    let force = p5.Vector.sub(targetVector,this.pos);
    let d = force.mag();
    d = constrain(d, 1, 25);
    var G = 50;
    var strength = G / (d * d);
    force.setMag(strength);
    if (d < 20) {
      force.mult(10);
    }
    /* changed to add force to acceleration
     * instead of velocity (physically accurate) */
    this.acc.add(force);  
  }
}

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按下鼠标时的矢量吸引力

Vector attraction when mouse pressed

javascript

p5.js