How to make ball bouncy in matterjs

p5.js Libraries
1

Hi I adapted this snippet of code from here However, despite the restitution, the objects aren’t bouncy at all. Is there anything I need to change?

// This example is based on examples from: http://brm.io/matter-js/

var Engine = Matter.Engine;
var Render = Matter.Render;
var World = Matter.World;
var Bodies = Matter.Bodies;
var Composite = Matter.Composite;

var engine;

var boxA;
var boxB;
var ground;

function setup() {
  createCanvas(800, 600);

  // create an engine
  engine = Engine.create();

 let options = {
    isStatic: true,
    restitution: 0.8
  }
  // create two boxes and a ground
  boxA = Bodies.rectangle(400, 200, 80, 80);
  //boxB = Bodies.circle(490, 50, 80, 80);
  boxB = Bodies.circle(490, 50, 20, 20);
  ground = Bodies.rectangle(400, 610, 810, 60, options);


  World.add(engine.world, [boxA, boxB, ground]);

  // run the engine
  Engine.run(engine);
}

// Using p5 to render
function draw() {

  // var bodies = Composite.allBodies(engine.world);

  background(51);

  var vertices = boxA.vertices;
  fill(255);
  beginShape();
  for (var i = 0; i < vertices.length; i++) {
    vertex(vertices[i].x, vertices[i].y);
  }
  endShape();

  // boxB vertices
  var vertices = boxB.vertices;
  fill(255);
  beginShape();
  for (var i = 0; i < vertices.length; i++) {
    vertex(vertices[i].x, vertices[i].y);
  }
  endShape();

  // Ground vertices
  var vertices = ground.vertices;
  beginShape();
  fill(127);
  for (var i = 0; i < vertices.length; i++) {
    vertex(vertices[i].x, vertices[i].y);
  }
  endShape();
}
1 Like
2

if you go
https://github.com/shiffman/p5-matter and

  • download the ZIP
  • unzip it to any directory
  • go down to
    …\p5-matter-master\01_basics\
  • double click index.html

i think you get what it is supposed to do??
( test under win7 / 64bit // firefox browser )

so can you tell us what/HOW you try to do it,
there is much more info about your working environment needed!

3

shouldn’t options be applied to the active bodies as well? this works with restitution set on both actives

2 Likes
4

Some very old posts about “matter.js” library: :link:

5

Thank you! It’s really helpful.