Tag Archives: QuickBox2D

QuickBox2D Revolute Ragdoll

By Zevan | August 9, 2009
CLICK HERE TO COPY
Actionscript:
  1. import com.actionsnippet.qbox.*;
  2. import Box2D.Common.Math.*;
  3.  
  4. [SWF (backgroundColor=0x000000, width=700, height=600, frameRate=60)]
  5.  
  6. var sim:QuickBox2D = new QuickBox2D(this,{debug:false, frim:true, gravityY:1});
  7.  
  8. sim.setDefault({fillColor:0x113366, fillAlpha:0.8, lineColor:0x3355AA});
  9.  
  10. sim.createStageWalls();
  11.  
  12. var circle:QuickObject = sim.addCircle({x:10, y:10, radius:3});
  13. var head:QuickObject = sim.addCircle({x:5, y:5, radius:0.5});
  14. var torsoA:QuickObject = sim.addBox({x:5, y:6, width:1.5, height:0.8})
  15. var torsoB:QuickObject = sim.addBox({x:5, y:6.5, width:1.25, height:0.8})
  16. var torsoC:QuickObject = sim.addBox({x:5, y:7, width:1.0, height:0.8})
  17. var pelvis:QuickObject = sim.addBox({x:5, y:7.5, width:1.0, height:0.8})
  18. var leftLegA:QuickObject = sim.addBox({x:4.75, y:8.5, width:0.4, height:1.75});
  19. var leftLegB:QuickObject = sim.addBox({x:4.75, y:9.75, width:0.4, height:1.5});
  20. var rightLegA:QuickObject = sim.addBox({x:5.29, y:8.5, width:0.4, height:1.75});
  21. var rightLegB:QuickObject = sim.addBox({x:5.29, y:9.75, width:0.4, height:1.5});
  22. var leftArmA:QuickObject = sim.addBox({x:3.6, y:5.8, width:1.3, height:0.35});
  23. var leftArmB:QuickObject = sim.addBox({x:2.5, y:5.8, width:1.25, height:0.35});
  24. var rightArmA:QuickObject = sim.addBox({x:6.4, y:5.8, width:1.3, height:0.35});
  25. var rightArmB:QuickObject = sim.addBox({x:7.5, y:5.8, width:1.25, height:0.35});
  26.  
  27. torsoA.body.SetLinearVelocity(new b2Vec2(0, 50));
  28.  
  29. var anchor:b2Vec2 = new b2Vec2();
  30. function connect(a:QuickObject, b:QuickObject, lower:Number, upper:Number, offX:Number=0, offY:Number = 0):QuickObject{
  31.      var min:Number = Math.min(a.y, b.y);
  32.      var max:Number = Math.max(a.y, b.y);
  33.      anchor.y = min + (max - min) * 0.5 + offY;
  34.      min = Math.min(a.x, b.x);
  35.      max = Math.max(a.x, b.x);
  36.      anchor.x = min + (max - min) * 0.5 + offX;
  37.     return sim.addJoint({a:a.body, b:b.body, x1:anchor.x, y1:anchor.y, lowerAngle:lower, upperAngle:upper});
  38. }
  39.  
  40. sim.setDefault({type:"revolute", collideConnected:false, enableLimit:true, lineColor:0xFFFFFF});
  41.  
  42. connect(head, torsoA, -.2, .2);
  43. connect(torsoA, torsoB,-.2, .2);
  44. connect(torsoC, torsoB,-.2, .2);
  45. connect(torsoC, pelvis,-.2, .2);
  46.  
  47. connect(pelvis, leftLegA, -1, 1, 0, -0.5);
  48. connect(leftLegA, leftLegB, -1, 1);
  49.  
  50. connect(pelvis, rightLegA, -1, 1, 0, -0.5);
  51. connect(rightLegA, rightLegB, -1, 1);
  52.  
  53. connect(torsoA, leftArmA, -2, 1);
  54. connect(leftArmA, leftArmB, -2, 1);
  55.  
  56. connect(torsoA, rightArmA, -1, 2)
  57. connect(rightArmA, rightArmB, -1, 2)
  58.  
  59. sim.start();
  60. sim.mouseDrag();

QuickBox2D alpha 108 is finally finished and different types of joints are now possible. I'll be auto-posting joint demos over the next few days for each type of Box2D joint. Box2D joints are pretty confusing, I struggled a bit to decide on a good way to handle them in QuickBox2D, any suggestions are welcome.


Have a look at the swf:

Posted in Box2D, QuickBox2D, motion | Also tagged , , , | 1 Comment

QuickBox2D Skinning

By Zevan | June 26, 2009
CLICK HERE TO COPY
Actionscript:
  1. import com.actionsnippet.qbox.*;
  2.  
  3. var sim:QuickBox2D = new QuickBox2D(this);
  4.  
  5. sim.createStageWalls({lineAlpha:0,fillColor:0x000000})
  6. sim.addBox({x:3, y:3, width:3, height:3, skin:BoxSkin});
  7. sim.addCircle({x:3, y:8,radius:1.5,  skin:CircleSkin});
  8. sim.addPoly({x:6, y:3, verts:[[1.5,0,3,3,0,3,1.5,0]], skin:TriangleSkin});
  9.  
  10. sim.addBox({x:6, y:3, width:3, height:3, skin:BoxSkin});
  11. sim.addCircle({x:6, y:8,radius:1.5,  skin:CircleSkin});
  12. sim.addPoly({x:12, y:3, verts:[[1.5,0,3,3,0,3,1.5,0]], skin:TriangleSkin});
  13.  
  14. sim.start();
  15. sim.mouseDrag();

You'll need this fla to run this snippet since the graphics are in the library. This snippet shows how to easily use linkage classes as the graphics for your rigid bodies. This was actually one of the first features I implemented in QuickBox2D.


Take a look at the swf here...

Posted in Box2D, MovieClip, QuickBox2D, motion | Also tagged , , , | 33 Comments

QuickBox2D groupIndex

By Zevan | June 25, 2009
CLICK HERE TO COPY
Actionscript:
  1. import com.actionsnippet.qbox.*;
  2. import Box2D.Common.Math.*;
  3.  
  4. stage.frameRate = 60;
  5.  
  6. var sim:QuickBox2D = new QuickBox2D(this);
  7.  
  8. sim.createStageWalls();
  9.  
  10. createTraveler(3, 3);
  11.  
  12. addObstacles();
  13.  
  14. function addObstacles():void{
  15.     sim.setDefault({groupIndex:-1, density:0, height:0.4});
  16.     sim.addBox({x:6, y:5, width:8, angle:0.17})
  17.     sim.addBox({x:7, y:7.1, width:8, angle:-0.17})
  18.     sim.addBox({x:5, y:9.1, width:8,  angle:0.10})
  19.     sim.addBox({x:6, y:11.5, width:8.9,  angle:-0.20})
  20.     sim.addBox({x:5.5, y:16, width:9, angle:0.20})
  21.     sim.addBox({x:5.5, y:18, width:9})
  22.     sim.addCircle({x:11, y:20, radius:2.5, groupIndex:1});
  23.     sim.addBox({x:16, y:19, width:2, height:2, angle:0.0, groupIndex:1})
  24. }
  25.  
  26. function createTraveler(x:Number, y:Number):QuickObject{
  27.     var parts:Array = [];
  28.     parts[0] = sim.addCircle({x:0, y:1, radius:0.25, friction:0.01});
  29.     parts[1] = sim.addCircle({x:0, y:3, radius:0.25, friction:0.01});
  30.     parts[2] = sim.addBox({x:0, y:2, width:0.3, height:1.5 , groupIndex:-1});
  31.     return sim.addGroup({objects:parts, x:x, y:y });
  32. }
  33.  
  34. sim.start();
  35. sim.mouseDrag();

One of the more advanced and useful properties of rigid bodies is the groupIndex. It allows you to specify which rigid bodies collide with one another and which rigid bodies pass through one another. This snippit demo's the groupIndex property. For more information take a look at what the Box2D manual says.

Take a look at the swf here.

Posted in Box2D, QuickBox2D, motion | Also tagged , , , | 5 Comments

QuickBox2D Chain

By Zevan | May 1, 2009
CLICK HERE TO COPY
Actionscript:
  1. import com.actionsnippet.qbox.*;
  2.  
  3. var sim:QuickBox2D = new QuickBox2D(this, {debug:true});
  4. // use the box2D default renderer (debug : true)
  5.  
  6. sim.createStageWalls();
  7.  
  8. // anchor
  9. var pre:QuickObject = sim.addCircle({x:9, y:3, radius:.5, density:0});
  10.  
  11. // create a chain of boxes
  12. for (var i:int = 0; i<12; i++){
  13.   var curr:QuickObject = sim.addBox({x:10 + i, y:3, width:.9, height:.9, angularDamping:1});
  14.                                                                  
  15.   // currently always adds a b2DistanceJoint
  16.   sim.addJoint({a:pre.body, b:curr.body,
  17.                            x1:9 + i, y1: 3, x2: 10 + i, y2:3, collideConnected:false});
  18.   pre = curr;
  19. }
  20.  
  21. // add a circle, use CCD (isBullet)
  22. sim.addCircle({x:20, y:10, radius:1, isBullet:true});
  23.  
  24. // start simulation
  25. sim.start();
  26. 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

//and the specific param properties are:
addCircle() : radius
addBox() : width, height
addPoly() : verts

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

Posted in Box2D, QuickBox2D, motion | Also tagged , , | 4 Comments