Examples

10 - Using restitution

Restitution is the energy transfer that occurs between two bodies when they hit each other. A restitution of 1 means a total energy transfer without energy loss ( such as a pool ball) and a restitution of 0 means a total energy loss without any energy transfer.

In this exemple, 3 pairs of balls hit each other with different restitution values. The two balls of the first pair have a restitution of 1; the second pair has a restitution of 0.5; the third pair has a restitution of 0.2. See what happend when balls hit each other.

Applet

Code

//Import all Phys2D libraries
import pphys2d.bodies.*;
import pphys2d.joints.*;
import pphys2d.shapes.*;
import pphys2d.phys2d.raw.collide.*;
import pphys2d.phys2d.raw.strategies.*;
import pphys2d.phys2d.raw.forcesource.*;
import pphys2d.phys2d.util.*;
import pphys2d.phys2d.raw.shapes.*;
import pphys2d.*;

//Create a PPhys2D world
PPWorld world = new PPWorld();

//Create PPhys2D Circle
PPCircle ball1;
PPCircle ball2;
PPCircle ball3;
PPCircle ball4;
PPCircle ball5;
PPCircle ball6;

void setup () {

  //Set size and framerate
  frameRate(30);
  size(500,500);

  //Set a standard world gravity
  world.setGravity(0, 0);


  //Set world edges in dark gray
  world.setEdges(this, new Color (40, 40, 40));

  //Add ball 1 to the world
  ball1 = new PPCircle(25);
  ball1.setPosition(50, 150);
  ball1.setStrokeWidth(1);
  ball1.setFillColor(new Color(40,40,100));
  ball1.setStrokeColor(new Color(40,40,40));
  ball1.addForce(1000000, 0);
  ball1.setRestitution(1);
  ball1.setDamping(0.5);
  world.add(ball1);

  //Add ball 2 to the world
  ball2 = new PPCircle(25);
  ball2.setPosition(450, 150);
  ball2.setStrokeWidth(1);
  ball2.setFillColor(new Color(40,40,100));
  ball2.setStrokeColor(new Color(40,40,40));
  ball2.addForce(-1000000, 0);
  ball2.setRestitution(1);
  ball2.setDamping(0.5);
  world.add(ball2);

  //Add ball 3 to the world
  ball3 = new PPCircle(25);
  ball3.setPosition(50, 250);
  ball3.setStrokeWidth(1);
  ball3.setFillColor(new Color(100,40,40));
  ball3.setStrokeColor(new Color(40,40,40));
  ball3.addForce(1000000, 0);
  ball3.setRestitution(0.5);
  ball3.setDamping(0.5);
  world.add(ball3);

  //Add ball 4 to the world
  ball4 = new PPCircle(25);
  ball4.setPosition(450, 250);
  ball4.setStrokeWidth(1);
  ball4.setFillColor(new Color(100,40,40));
  ball4.setStrokeColor(new Color(40,40,40));
  ball4.addForce(-1000000, 0);
  ball4.setRestitution(0.5);
  ball4.setDamping(0.5);
  world.add(ball4);

  //Add ball 5 to the world
  ball5 = new PPCircle(25);
  ball5.setPosition(50, 350);
  ball5.setStrokeWidth(1);
  ball5.setFillColor(new Color(40,100,40));
  ball5.setStrokeColor(new Color(40,40,40));
  ball5.addForce(1000000, 0);
  ball5.setRestitution(0.2);
  ball5.setDamping(0.5);
  world.add(ball5);

  //Add ball 6 to the world
  ball6 = new PPCircle(25);
  ball6.setPosition(450, 350);
  ball6.setStrokeWidth(1);
  ball6.setFillColor(new Color(40,100,40));
  ball6.setStrokeColor(new Color(40,40,40));
  ball6.addForce(-1000000, 0);
  ball6.setRestitution(0.2);
  ball6.setDamping(0.5);
  world.add(ball6);
}

void draw () {
  //Clear screen
  background(255);
  //Draw world
  world.draw(this);
}