function init() {dm = new ht.DataModel();g3d = new ht.graph3d.Graph3dView(dm);g3d.setGridVisible(true);g3d.addToDOM();g3d.setEye(100, 50, 150);// Define the worldvar gravity = new b2Vec2(0, -100); var doSleep = false; world = new b2World(gravity, doSleep); createNode([0, -3, 0], [100, 6, 100], false, 0); createNode([-100, -50, 0], [400, 6, 100], false, -Math.PI/8); createNode([100, -50, 0], [50, 6, 100], false, Math.PI/6);  createNode([1, 50, 0], [10, 10, 10], true); createNode([-1, 90, 0], [10, 10, 10], true); render(); } function createNode(p3, s3, dynamic, angle) { var node = new ht.Node(); node.p3(p3); node.s3(s3); node.setRotationZ(angle == null ? Math.PI * Math.random() : angle); dm.add(node); var fixDef = new b2FixtureDef(); if (dynamic) { fixDef.density = 0.5; fixDef.friction = 0.5; fixDef.restitution = 0.5; node.s({ 'all.color': 'red', 'batch': 'dynamic' }); } else { fixDef.density = 0.0; } var shape = new b2PolygonShape(); shape.SetAsBox(s3[0] / 2, s3[1] / 2); fixDef.shape = shape; var bodyDef = new b2BodyDef(); bodyDef.type = dynamic ? b2Body.b2_dynamicBody : b2Body.b2_staticBody; bodyDef.position.Set(p3[0], p3[1]); bodyDef.angle = node.getRotationZ(); bodyDef.userData = node; world.CreateBody(bodyDef).CreateFixture(fixDef); } count = 0 function render() { count++; if(count % 10 === 0){ createNode([-1, 50, 0], [10, 10, 10], true); } world.Step(1 / 60, 10, 10); var list = world.GetBodyList(); while (list) { var node = list.m_userData; if(node){ var position = list.GetPosition(); if(position.y < -150 || g3d.isSelected(node)){ dm.remove(node); world.DestroyBody(list); }else{ node.p3(position.x, position.y, 0); node.setRotationZ(list.GetAngle()); } } list = list.GetNext(); } requestAnimationFrame(render); }