低速时不遵守反射定律的物体

我试图模拟一个球在台球桌上弹跳,遇到了很多问题。(视图从上方俯视桌子)。

Angle of incidence = angle of reflection

在右边界上的模拟结束时,球似乎沿着它滚动。为什么它不遵循反射定律?

例子: https://jsfiddle.net/5sjx7oyw/

    var Engine = Matter.Engine,
    Render = Matter.Render,
    World = Matter.World,
    Bodies = Matter.Bodies,
    Body = Matter.Body,
    Vector = Matter.Vector,
    Events = Matter.Events;

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

var canvas = document.getElementById('canvas');

engine.world.gravity.y = 0; // gravity not needed in this app

// create a renderer
var render = Render.create({
    element: document.body,
    canvas: canvas,
    engine: engine,
    options: {wireframes: true}
});

var ball_options = {
    density: 0.04,
  restitution: 1,// 0 = no bouncing, 1 = 100% of kinetic energy bounce back
  friction: 0,
  frictionAir: 0.05,
  inertia: Infinity
};

var boundary_options = {
  isStatic: true
};

var ball = Bodies.circle(100, 150, 11, ball_options);

var boundary_left = Bodies.rectangle(10, 160, 100, 200, boundary_options);
var boundary_right = Bodies.rectangle(300, 160, 100, 200, boundary_options);
var boundary_top = Bodies.rectangle(150, 10, 200, 100, boundary_options);
var boundary_bottom = Bodies.rectangle(150, 300, 200, 100, boundary_options);

// add all of the bodies to the world
World.add(engine.world, [
    boundary_left,
  boundary_right,
  boundary_top,
  boundary_bottom,
  ball
  ]);

render.options.height = 300;
canvas.height = 300;
Engine.run(engine);
Render.run(render);

Body.applyForce(ball, { x: 0, y: 0 }, { x: 0.2, y: 0.5 });