QuickBox2D Chain

import com.actionsnippet.qbox.*;

var sim:QuickBox2D = new QuickBox2D(this, {debug:true});
// use the box2D default renderer (debug : true)

sim.createStageWalls();

// anchor
var pre:QuickObject = sim.addCircle({x:9, y:3, radius:.5, density:0});

// create a chain of boxes
for (var i:int = 0; i<12; i++){
  var curr:QuickObject = sim.addBox({x:10 + i, y:3, width:.9, height:.9, angularDamping:1});
									                             
  // currently always adds a b2DistanceJoint
  sim.addJoint({a:pre.body, b:curr.body, 
			               x1:9 + i, y1: 3, x2: 10 + i, y2:3, collideConnected:false});
  pre = curr;
}

// add a circle, use CCD (isBullet)
sim.addCircle({x:20, y:10, radius:1, isBullet:true});

// start simulation
sim.start();
sim.mouseDrag();

This snippet uses my QuickBox2D library to create a chain. QuickBox2D is a wrapper for Box2DFlashAS3 that greatly simplifies world setup, instantiation and graphical skinning of rigid bodies (more info on yesterdays post)…

See the swf here .

Download Box2DFlashAS3 here

Download QuickBox2D Alpha 104 here

See yesterdays post for additional information. I’m still in the process of writing some docs and possibly a tutorial for QuickBox2D… hopefully I’ll finish with that soon…

If your somewhat familiar with Box2D and just want to just dig right in, the following scrap of information may help:


// Methods of the QuickBox2D class, used for creating rigid bodies and joints
addCircle();
addBox();
addPoly();
// currently only creates b2DistanceJoints
addJoint();

these function all take one parameter Object as their argument. The common parameter properties for rigid bodies are:

// QuickBox2D simpleRender settings:
lineColor:0x000000
lineAlpha:1
lineThickness:0
fillColor:0xCCCCCC
fillAlpha:1
// wrapped Box2D properties
x:3
y:3
density:1
friction:0.5
restitution:0.2
angle: 0
linearDamping:0
angularDamping:0
isBullet:false,
fixedRotation:false
allowSleep: true
isSleeping:false
// advanced use
maskBits:0xFFFF
categoryBits:1
groupIndex:0

//Joints have the following properties... not going to bother explaining these until I write the docs:
addJoint() : a, b, x1, x2, y1, y2