removing particles

[yarrasid]

I'll admit that I am new to as3 so please excuse my ignorance.

I began using this fantastic engine recently, but unfortunately I
don't seem to be even capable of mastering the basics. My problem is
in removing particles from a group/simulation. I am currently using
the removeParticle() method, but it does not work consistently.

This is the entire code (changed very slightly from an example):



import org.cove.ape.*;
import flash.events.Event;
import flash.events.KeyboardEvent;
import flash.display.Sprite;

// listeners
addEventListener(Event.ENTER_FRAME, TimeStep);
stage.addEventListener(KeyboardEvent.KEY_DOWN, KeyPressed);
stage.addEventListener(KeyboardEvent.KEY_UP, KeyReleased);
//Ape
// ape init
APEngine.init(1/4);
APEngine.container = this;
APEngine.addForce(new VectorForce(false,0,2));
var defaultGroup:Group = new Group();
defaultGroup.collideInternal = true;
var ground1:RectangleParticle = new
RectangleParticle(150,200,200,10,-0.1,true);
defaultGroup.addParticle(ground1);
var ground2:RectangleParticle = new
RectangleParticle(300,50,300,10,0,true);
defaultGroup.addParticle(ground2);
var ground3:RectangleParticle = new
RectangleParticle(120,55,30,30,0,true);
defaultGroup.addParticle(ground3);

var wheel1: WheelParticle = new WheelParticle(160,20,10,false,2);
defaultGroup.addParticle(wheel1);
var wheel2: WheelParticle = new WheelParticle(200,20,10,false,2);
defaultGroup.addParticle(wheel2);

var wheel4:SpringConstraint = new SpringConstraint(wheel1, wheel2,
0.5, true, 1);
defaultGroup.addConstraint(wheel4);

// styles and displays

ground1.setStyle(0, 0xFF0000, 1, 0xFF0000,0.5);
ground2.setStyle(0, 0xFF0000, 1, 0xFF0000,0.5);
ground3.setStyle(0, 0xFF0000, 1, 0xFF0000,0.5);
wheel2.setStyle(0, 0xFF0000, 1, 0xFF0000,0.5);
wheel1.setStyle(0, 0xFF0000, 1, 0xFF0000,0.5);


APEngine.addGroup(defaultGroup);

var win = false;
//
function KeyPressed(event:KeyboardEvent):void {
if (event.keyCode == Keyboard.UP) {
wheel1.angularVelocity = 0.5;
wheel2.angularVelocity = 0.5;
}
if (event.keyCode == Keyboard.DOWN) {
wheel1.angularVelocity =- 0.5;
wheel2.angularVelocity =- 0.5;
}
}

function KeyReleased(event:KeyboardEvent):void {
wheel1.angularVelocity = 0;
wheel2.angularVelocity = 0;
}
var timer:Number=20;
function TimeStep(evt:Event):void {
if (timer==0) {
defaultGroup.removeParticle(ground3);
var rectangle1: RectangleParticle = new RectangleParticle(150, -100,
80, 2, 45, false, 10, 0.3, .5);
defaultGroup.addParticle(rectangle1);
rectangle1.setStyle(0, 0xFF0000, 1, 0xFF0000,0.5);
}
if (timer==-40) {
trace(timer);
defaultGroup.removeParticle(rectangle1);

}
timer--;
APEngine.step();
APEngine.paint();
}



The problem in in the TimeStep function. The following code:
defaultGroup.removeParticle(rectangle1); does not execute properly.
Any help would be very much appreciated. Thank you very much for your
time.