Пишу Ragdoll

[Crash512]

Спасибо за ответ=) Странно... У меня весь этот "рэгдолл" теперь непрерывно вращается по часовой стрелке... Код скопировал полностью=)

[Герыч]

Вот, даже сделал всё с классами) теперь все joint'ы в одном месте:

package gerich.verlet
{
	import flash.display.Shape;
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.MouseEvent;
 
	public class Main extends Sprite
	{
		private var pt:Array = new Array();
		private var joints:Array = new Array();
		private var mousejoints:Array = new Array();
		private var particles:Sprite = new Sprite();
		private var canvas:Shape = new Shape();
		private var grav:Number = 100;
		private var timeSqr:Number;
 
		// ========================================================== //
		public function Main():void
		{
			stage.frameRate = 40;
 
			timeSqr=1/stage.frameRate;timeSqr*=timeSqr;
 
			addChild(canvas);
 
			addChild(particles);
 
			pt.push(new Particle(270,150));
			pt.push(new Particle(270,175));
			pt.push(new Particle(270,200));
			pt.push(new Particle(270,225));
			pt.push(new Particle(270,250));
			pt.push(new Particle(270,275));
			pt.push(new Particle(255,285));
			pt.push(new Particle(285,285));
 
			joints.push(new MouseJoint(pt[0], pt[1], 25));
			joints.push(new Joint(pt[1], pt[2], 25));
			joints.push(new Joint(pt[2], pt[3], 25));
			joints.push(new Joint(pt[3], pt[4], 25));
			joints.push(new Joint(pt[4], pt[5], 25));
			joints.push(new Joint(pt[5], pt[6], 25));
			joints.push(new Joint(pt[5], pt[7], 25));
			joints.push(new Joint(pt[6], pt[7], 25));
 
			for (var i in joints)
			{
				if(joints[i] is MouseJoint)
					mousejoints.push(joints[i]);
			}
 
			for (var i in pt)
			{
				particles.addChild(pt[i]);
			}
 
			addEventListener(Event.ENTER_FRAME, checkJoints);
			addEventListener(Event.ENTER_FRAME, ptMouse);
		}
		// ========================================================== //
		private function checkJoints(event:Event):void
		{
			var dx:Number;
			var dy:Number;
 
			canvas.graphics.clear();
 
			// Gravity
 
			for (var i in pt)
			{
				dx = (pt[i].xx - pt[i].old_x);
				dy = (pt[i].yy - pt[i].old_y);
				pt[i].old_x = pt[i].xx;
				pt[i].old_y = pt[i].yy;
				pt[i].xx += dx;
				pt[i].yy += dy+grav*timeSqr;
			}
 
			// Joints
 
			for (var z:int=0; z<5; z++)
			{
				for (var i in joints)
				{
					joints[i].Apply();
				}
			}
 
			for (var i in pt)
			{
				pt[i].x = pt[i].xx;
				pt[i].y = pt[i].yy;
			}
			// Lines
			for (var i in joints)
			{
				joints[i].Draw(canvas);
			}
		}
		// ========================================================== //
		private function ptMouse(event:Event):void
		{
			for (var i in mousejoints)
			{
				mousejoints[i].SetMouse( mouseX,mouseY);
				mousejoints[i].Draw(canvas);;
			}
		}
	}
}
 
// ***** [ Particle Class ] ***************************************** //
 
import flash.display.Sprite;
 
internal class Particle extends Sprite
{
	public var old_x:Number;
	public var old_y:Number;
	public var xx:Number;
	public var yy:Number;
 
	// ========================================================== //
	public function Particle(_x:int, _y:int):void
	{
		x = _x;
		y = _y;
 
		xx = _x;
		yy = _y;
 
		old_x = _x;
		old_y = _y;
 
		graphics.lineStyle(1, 0x000000);
		graphics.beginFill(0xFFD22B);
		graphics.drawCircle(0,0,5);
		graphics.endFill();
	}
	// ========================================================== //
}
 
import flash.display.Shape;
 
internal class Joint
{
	public var p1:Particle;
	public var p2:Particle;
	public var len:Number;
 
	// ========================================================== //
	public function Joint(_p1:Particle, _p2:Particle, _len:Number):void
	{
		p1=_p1;
		p2=_p2;
		len=_len;
	}
	// ========================================================== //
 
	public function Draw(canvas:Shape):void
	{
		canvas.graphics.lineStyle(1,0x000000);
		canvas.graphics.moveTo(p1.x, p1.y);
		canvas.graphics.lineTo(p2.x, p2.y);
	}
	// ========================================================== //
 
	public function Apply():void
	{
		var dx:Number;
		var dy:Number;
		var d_len:Number;
		var diff:Number;
 
		dx = p2.xx-p1.xx;
		dy = p2.yy-p1.yy;
		d_len = Math.sqrt(dx*dx + dy*dy);
		diff = (d_len-len)/d_len;
		dx *= 0.5*diff;
		dy *= 0.5*diff;
 
		p2.xx -= dx;
		p2.yy -= dy;
		p1.xx += dx;
		p1.yy += dy;
	}
	// ========================================================== //
}
 
internal class MouseJoint extends Joint
{
	// ========================================================== //
	public function MouseJoint(_p1:Particle, _p2:Particle, _len:Number):void
	{
		super(_p1,_p2,_len);
	}
 
	// ========================================================== //
	override public function Apply():void
	{
			var dx:Number;
			var dy:Number;
			var d_len:Number;
			var diff:Number;
 
			dx = p2.xx-p1.xx;
			dy = p2.yy-p1.yy;
			d_len = Math.sqrt(dx*dx + dy*dy);
			diff = (d_len-len)/d_len;
			dx *= diff;
			dy *= diff;
 
			p2.xx -= dx;
			p2.yy -= dy;
	}
 
	// ========================================================== //
	public function SetMouse(mousex:Number,mousey:Number):void
	{
			p1.x =mousex;
			p1.xx=mousex;
			p1.y =mousey;
			p1.yy=mousey;
	}
	// ========================================================== //
}

P.S. Одна из первых прог с классами на AS3.. лёгкий язык.. очень)

Добавлено через 1 минуту

Сообщение от Crash512

Спасибо за ответ=) Странно... У меня весь этот "рэгдолл" теперь непрерывно вращается по часовой стрелке... Код скопировал полностью=)

Я убрал трение вроде.. как я понял оно у тя было

Добавлено через 3 минуты
ну ещё я ведь добавил время... а вообще спасибо тебе) прочитал статейку про верлета, лень было самому всё писать, а тут бац почти всё готово)

[Crash512]

Блин.. Всё равно вращается=)) Что я не так делаю?.. Можешь прислать исходник, если у тебя всё нормально?

[Герыч]

я ж говорю, у тя было:

				dx = (pt[i].x - pt[i].old_x);
				dy = (pt[i].y - pt[i].old_y) + grav;
				pt[i].old_x = pt[i].x;
				pt[i].old_y = pt[i].y;
				pt[i].x += dx/1.1;
				pt[i].y += dy/1.1;

а я сделал

				dx = (pt[i].xx - pt[i].old_x);
				dy = (pt[i].yy - pt[i].old_y);
				pt[i].old_x = pt[i].xx;
				pt[i].old_y = pt[i].yy;
				pt[i].xx += dx;
				pt[i].yy += dy+grav*timeSqr;

я тут dx и dy чуток по-другому считаю.. и тут нет силы трения

кстати, что значит 1.1 тут:

				pt[i].x += dx/1.1;
				pt[i].y += dy/1.1;

Добавлено через 3 часа 9 минут
Сделал "слабые связи" всмысле как верёвка, а не палка постоянной длины:

package gerich.verlet
{
	import flash.display.Shape;
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.MouseEvent;
 
	public class Main extends Sprite
	{
		private var pt:Array = new Array();
		private var joints:Array = new Array();
		private var mousejoints:Array = new Array();
		private var particles:Sprite = new Sprite();
		private var canvas:Shape = new Shape();
		private var grav:Number = 100;
		private var timeSqr:Number;
 
		// ========================================================== //
		public function Main():void
		{
			stage.frameRate = 40;
 
			timeSqr=1/stage.frameRate;timeSqr*=timeSqr;
 
			addChild(canvas);
 
			addChild(particles);
 
			pt.push(new Particle(270,150));
			pt.push(new Particle(270,175));
 
			joints.push(new WeakMouseJoint(pt[0], pt[1], 10));
 
			for (var j:int=1;j<100;j++)
			{
				pt.push(new Particle(270,175));
				joints.push(new WeakJoint(pt[j], pt[j+1], 10));
			}
 
			for (var i in joints)
			{
				if(joints[i] is MouseJoint)
					mousejoints.push(joints[i]);
			}
 
			for (var i in pt)
			{
				particles.addChild(pt[i]);
			}
 
			addEventListener(Event.ENTER_FRAME, checkJoints);
			addEventListener(Event.ENTER_FRAME, ptMouse);
		}
		// ========================================================== //
		private function checkJoints(event:Event):void
		{
			var dx:Number;
			var dy:Number;
 
			canvas.graphics.clear();
 
			// Gravity
 
			for (var i in pt)
			{
				dx = (pt[i].xx - pt[i].old_x);
				dy = (pt[i].yy - pt[i].old_y);
				pt[i].old_x = pt[i].xx;
				pt[i].old_y = pt[i].yy;
				pt[i].xx += dx;
				pt[i].yy += (dy+grav*timeSqr);
			}
 
			// Joints
 
			for (var z:int=0; z<10; z++)
			{
				for (var i in joints)
				{
					joints[i].Apply();
				}
				for (var i in pt)
				{
					pt[i].xx=Math.max(pt[i].xx,0);
					pt[i].xx=Math.min(pt[i].xx,stage.stageWidth);
					pt[i].yy=Math.max(pt[i].yy,0);
					pt[i].yy=Math.min(pt[i].yy,stage.stageHeight);
				}
			}
 
			for (var i in pt)
			{
				pt[i].x = pt[i].xx;
				pt[i].y = pt[i].yy;
			}
			// Lines
			for (var i in joints)
			{
				joints[i].Draw(canvas);
			}
		}
		// ========================================================== //
		private function ptMouse(event:Event):void
		{
			for (var i in mousejoints)
			{
				mousejoints[i].SetMouse( mouseX,mouseY);
				mousejoints[i].Draw(canvas);;
			}
		}
	}
}
 
// ***** [ Particle Class ] ***************************************** //
 
import flash.display.Sprite;
 
internal class Particle extends Sprite
{
	public var old_x:Number;
	public var old_y:Number;
	public var xx:Number;
	public var yy:Number;
 
	// ========================================================== //
	public function Particle(_x:int, _y:int):void
	{
		x = _x;
		y = _y;
 
		xx = _x;
		yy = _y;
 
		old_x = _x;
		old_y = _y;
 
		graphics.lineStyle(1, 0x000000);
		graphics.beginFill(0xFFD22B);
		graphics.drawCircle(0,0,5);
		graphics.endFill();
	}
	// ========================================================== //
}
 
import flash.display.Shape;
 
internal class Joint
{
	public var p1:Particle;
	public var p2:Particle;
	public var len:Number;
 
	// ========================================================== //
	public function Joint(_p1:Particle, _p2:Particle, _len:Number):void
	{
		p1=_p1;
		p2=_p2;
		len=_len;
	}
	// ========================================================== //
 
	public function Draw(canvas:Shape):void
	{
		canvas.graphics.lineStyle(1,0x000000);
		canvas.graphics.moveTo(p1.x, p1.y);
		canvas.graphics.lineTo(p2.x, p2.y);
	}
	// ========================================================== //
 
	public function Apply():void
	{
		var dx:Number;
		var dy:Number;
		var d_len:Number;
		var diff:Number;
 
		dx = p2.xx-p1.xx;
		dy = p2.yy-p1.yy;
		d_len = Math.sqrt(dx*dx + dy*dy);
		diff = (d_len-len)/d_len;
		dx *= 0.5*diff;
		dy *= 0.5*diff;
 
		p2.xx -= dx;
		p2.yy -= dy;
		p1.xx += dx;
		p1.yy += dy;
	}
	// ========================================================== //
}
 
internal class MouseJoint extends Joint
{
	// ========================================================== //
	public function MouseJoint(_p1:Particle, _p2:Particle, _len:Number):void
	{
		super(_p1,_p2,_len);
	}
 
	// ========================================================== //
	override public function Apply():void
	{
			var dx:Number;
			var dy:Number;
			var d_len:Number;
			var diff:Number;
 
			dx = p2.xx-p1.xx;
			dy = p2.yy-p1.yy;
			d_len = Math.sqrt(dx*dx + dy*dy);
			diff = (d_len-len)/d_len;
			dx *= diff;
			dy *= diff;
 
			p2.xx -= dx;
			p2.yy -= dy;
	}
 
	// ========================================================== //
	public function SetMouse(mousex:Number,mousey:Number):void
	{
			p1.x =mousex;
			p1.xx=mousex;
			p1.y =mousey;
			p1.yy=mousey;
	}
	// ========================================================== //
}
 
internal class WeakJoint extends Joint
{
	// ========================================================== //
	public function WeakJoint(_p1:Particle, _p2:Particle, _len:Number):void
	{
		super(_p1,_p2,_len);
	}
 
	// ========================================================== //
	override public function Apply():void
	{
			var dx:Number;
			var dy:Number;
			var d_len:Number;
			var diff:Number;
 
			dx = p2.xx-p1.xx;
			dy = p2.yy-p1.yy;
			d_len = Math.sqrt(dx*dx + dy*dy);
			if(d_len>len){
				diff = (d_len-len)/d_len;
				dx *= diff;
				dy *= diff;
 
				p2.xx -= dx;
				p2.yy -= dy;
				p1.xx += dx;
				p1.yy += dy;
			}
	}
 
	// ========================================================== //
}
 
internal class WeakMouseJoint extends MouseJoint
{
	// ========================================================== //
	public function WeakMouseJoint(_p1:Particle, _p2:Particle, _len:Number):void
	{
		super(_p1,_p2,_len);
	}
 
	// ========================================================== //
	override public function Apply():void
	{
			var dx:Number;
			var dy:Number;
			var d_len:Number;
			var diff:Number;
 
			dx = p2.xx-p1.xx;
			dy = p2.yy-p1.yy;
			d_len = Math.sqrt(dx*dx + dy*dy);
			if(d_len>len)
			{
				diff = (d_len-len)/d_len;
				dx *= diff;
				dy *= diff;
 
				p2.xx -= dx;
				p2.yy -= dy;
			}
		}
 
	// ========================================================== //
}

[Герыч]

package gerich.verlet
{
	import flash.display.Shape;
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.MouseEvent;
 
	public class Main extends Sprite{
		private var pt:Array = new Array();
		private var joints:Array = new Array();
		private var particles:Sprite = new Sprite();
		private var canvas:Shape = new Shape();
		private var grav:Number = 100;
		private var timeSqr:Number;
 
		// ========================================================== //
		public function Main():void{
			stage.frameRate = 40;
 
			timeSqr=1/stage.frameRate;timeSqr*=timeSqr;
 
			addChild(canvas);
 
			addChild(particles);
 
			pt.push(new Particle(270,150,true));
 
			for (var j:int=0;j<30;j++)
			{
				pt.push(new Particle(270,175));
				joints.push(new WeakJoint(pt[j], pt[j+1], 10));
			}
 
 
			for (var i in pt){
				particles.addChild(pt[i]);
			}
 
			addEventListener(Event.ENTER_FRAME, checkJoints);
			addEventListener(Event.ENTER_FRAME, ptMouse);
		}
		// ========================================================== //
 
		private function checkJoints(event:Event):void{
			var dx:Number;
			var dy:Number;
 
			canvas.graphics.clear();
 
			// Gravity
 
			for (var i in pt){
				dx = (pt[i].xx - pt[i].old_x);
				dy = (pt[i].yy - pt[i].old_y);
				pt[i].old_x = pt[i].xx;
				pt[i].old_y = pt[i].yy;
				pt[i].xx += dx;
				pt[i].yy += (dy+grav*timeSqr);
			}
 
			// Joints
 
 
			for (var z:int=0; z<30; z++){
				for (var i in joints){
					joints[i].Apply();
				}
 
				for (var i in pt){
					pt[i].xx=Math.max(pt[i].xx,0);
					pt[i].xx=Math.min(pt[i].xx,stage.stageWidth);
					pt[i].yy=Math.max(pt[i].yy,0);
					pt[i].yy=Math.min(pt[i].yy,stage.stageHeight);
				}
			}
 
			for (var i in pt){
				pt[i].x = pt[i].xx;
				pt[i].y = pt[i].yy;
			}
			// Lines
			for (var i in joints){
				joints[i].Draw(canvas);
			}
		}
		// ========================================================== //
		private function ptMouse(event:Event):void{
			for (var i in pt){
				if(pt[i].isMouse){
					pt[i].x=mouseX;
					pt[i].y=mouseY;
					pt[i].xx=mouseX;
					pt[i].yy=mouseY;
				}
			}
			canvas.graphics.clear();
			// Lines
			for (var i in joints){
				joints[i].Draw(canvas);
			}
		}
	}
}
 
// ***** [ Particle Class ] ***************************************** //
 
	import flash.display.Sprite;
 
	internal class Particle extends Sprite{
		public var old_x:Number;
		public var old_y:Number;
		public var xx:Number;
		public var yy:Number;
		public var isMouse:Boolean;
 
		// ========================================================== //
		public function Particle(_x:int, _y:int, _isMouse:Boolean=false):void{
			x = _x;
			y = _y;
 
			xx = _x;
			yy = _y;
 
			old_x = _x;
			old_y = _y;
 
			isMouse=_isMouse;
 
			graphics.lineStyle(1, 0x000000);
			graphics.beginFill(0xFFD22B);
			graphics.drawCircle(0,0,5);
			graphics.endFill();
		}
		// ========================================================== //
	}
 
	import flash.display.Shape;
 
	internal class Joint{
		public var p1:Particle;
		public var p2:Particle;
		public var len:Number;
 
		// ========================================================== //
		public function Joint(_p1:Particle, _p2:Particle, _len:Number):void{
			p1=_p1;
			p2=_p2;
			len=_len;
		}
		// ========================================================== //
 
		public function Draw(canvas:Shape):void{
			canvas.graphics.lineStyle(1,0x000000);
			canvas.graphics.moveTo(p1.x, p1.y);
			canvas.graphics.lineTo(p2.x, p2.y);
		}
		// ========================================================== //
 
		public function Apply():void{
			var dx:Number;
			var dy:Number;
			var d_len:Number;
			var diff:Number;
 
			dx = p2.xx-p1.xx;
			dy = p2.yy-p1.yy;
			d_len = Math.sqrt(dx*dx + dy*dy);
			diff = (d_len-len)/d_len;
			dx *= 0.5*diff;
			dy *= 0.5*diff;
 
			if(!p2.isMouse){
				p2.xx -= dx;
				p2.yy -= dy;
			}
			if(!p1.isMouse){
				p1.xx += dx;
				p1.yy += dy;
			}
 
		}
		// ========================================================== //
	}
 
	internal class WeakJoint extends Joint
	{
		// ========================================================== //
		public function WeakJoint(_p1:Particle, _p2:Particle, _len:Number):void{
			super(_p1,_p2,_len);
		}
 
		// ========================================================== //
		override public function Apply():void{
			var dx:Number;
			var dy:Number;
			var d_len:Number;
			var diff:Number;
 
			dx = p2.xx-p1.xx;
			dy = p2.yy-p1.yy;
			d_len = Math.sqrt(dx*dx + dy*dy);
			if(d_len>len){
				diff = (d_len-len)/d_len;
				dx *= diff;
				dy *= diff;
 
				if(!p2.isMouse){
					p2.xx -= dx;
					p2.yy -= dy;
				}
				if(!p1.isMouse){
					p1.xx += dx;
					p1.yy += dy;
				}
			}
		}
 
		// ========================================================== //
	}
 
	internal class RangeJoint extends Joint
	{
		public var lenmax:Number;
		public var lenmin:Number;
		// ========================================================== //
		public function RangeJoint(_p1:Particle, _p2:Particle, _lenmax:Number, _lenmin:Number):void
		{
			lenmax=_lenmax;
			lenmin=_lenmin;
			super(_p1,_p2,_lenmax);
		}
 
		// ========================================================== //
		override public function Apply():void
		{
			var dx:Number;
			var dy:Number;
			var d_len:Number;
			var diff:Number;
 
			dx = p2.xx-p1.xx;
			dy = p2.yy-p1.yy;
			d_len = Math.sqrt(dx*dx + dy*dy);
			if((d_len>lenmax)||(d_len<lenmin)){
				if(d_len>lenmax)
					diff = (d_len-lenmax)/d_len;
				if(d_len<lenmin)
					diff = (d_len-lenmin)/d_len;
				dx *= diff;
				dy *= diff;
 
				if(!p2.isMouse){
					p2.xx -= dx;
					p2.yy -= dy;
				}
				if(!p1.isMouse){
					p1.xx += dx;
					p1.yy += dy;
				}
			}
		}
		// ========================================================== //
	}

Теперь работы с мышью более логична) в классе Particle добавил свойство isMouse и убрал лишние классы

[Герыч]

Сделал проверку на нулевую длину для связей:

package gerich.verlet
{
	import flash.display.Shape;
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.MouseEvent;
 
	public class Main extends Sprite{
		private var pt:Array = new Array();
		private var joints:Array = new Array();
		private var particles:Sprite = new Sprite();
		private var canvas:Shape = new Shape();
		private var grav:Number = 500;
		private var timeSqr:Number;
 
		// ========================================================== //
		public function Main():void{
			stage.frameRate = 40;
 
			timeSqr=1/stage.frameRate;timeSqr*=timeSqr;
 
			addChild(canvas);
 
			addChild(particles);
 
			pt.push(new Particle(270,150,true));
 
			for (var j:int=0;j<30;j++)
			{
				pt.push(new Particle(270,150));
				joints.push(new RangeJoint(pt[j], pt[j+1], 8, 20));
			}
 
 
			for (var i in pt){
				particles.addChild(pt[i]);
			}
 
			addEventListener(Event.ENTER_FRAME, checkJoints);
			addEventListener(Event.ENTER_FRAME, ptMouse);
		}
		// ========================================================== //
 
		private function checkJoints(event:Event):void{
			var dx:Number;
			var dy:Number;
 
			canvas.graphics.clear();
 
			// Gravity
 
			for (var i in pt){
				dx = (pt[i].xx - pt[i].old_x);
				dy = (pt[i].yy - pt[i].old_y);
				pt[i].old_x = pt[i].xx;
				pt[i].old_y = pt[i].yy;
				pt[i].xx += dx;
				pt[i].yy += (dy+grav*timeSqr);
			}
 
			// Joints
 
 
			for (var z:int=0; z<30; z++){
				for (var i in joints){
					joints[i].Apply();
				}
 
				for (var i in pt){
					pt[i].xx=Math.max(pt[i].xx,0);
					pt[i].xx=Math.min(pt[i].xx,stage.stageWidth);
					pt[i].yy=Math.max(pt[i].yy,0);
					pt[i].yy=Math.min(pt[i].yy,stage.stageHeight);
				}
			}
 
			for (var i in pt){
				pt[i].x = pt[i].xx;
				pt[i].y = pt[i].yy;
			}
			// Lines
			for (var i in joints){
				joints[i].Draw(canvas);
			}
		}
		// ========================================================== //
		private function ptMouse(event:Event):void{
			for (var i in pt){
				if(pt[i].isMouse){
					pt[i].x=mouseX;
					pt[i].y=mouseY;
					pt[i].xx=mouseX;
					pt[i].yy=mouseY;
				}
			}
			canvas.graphics.clear();
			// Lines
			for (var i in joints){
				joints[i].Draw(canvas);
			}
		}
	}
}
 
// ***** [ Particle Class ] ***************************************** //
 
	import flash.display.Sprite;
 
	internal class Particle extends Sprite{
		public var old_x:Number;
		public var old_y:Number;
		public var xx:Number;
		public var yy:Number;
		public var isMouse:Boolean;
 
		// ========================================================== //
		public function Particle(_x:int, _y:int, _isMouse:Boolean=false):void{
			x = _x;
			y = _y;
 
			xx = _x;
			yy = _y;
 
			old_x = _x;
			old_y = _y;
 
			isMouse=_isMouse;
 
			graphics.lineStyle(1, 0x000000);
			graphics.beginFill(0xFFD22B);
			graphics.drawCircle(0,0,5);
			graphics.endFill();
		}
		// ========================================================== //
	}
 
	import flash.display.Shape;
 
	internal class Joint{
		public var p1:Particle;
		public var p2:Particle;
		public var len:Number;
 
		// ========================================================== //
		public function Joint(_p1:Particle, _p2:Particle, _len:Number):void{
			p1=_p1;
			p2=_p2;
			len=_len;
		}
		// ========================================================== //
 
		public function Draw(canvas:Shape):void{
			canvas.graphics.lineStyle(1,0x000000);
			canvas.graphics.moveTo(p1.x, p1.y);
			canvas.graphics.lineTo(p2.x, p2.y);
		}
		// ========================================================== //
 
		public function Apply():void{
			var dx:Number;
			var dy:Number;
			var d_len:Number;
			var diff:Number;
 
			dx = p2.xx-p1.xx;
			dy = p2.yy-p1.yy;
			d_len = Math.sqrt(dx*dx + dy*dy);
			if(d_len==0){
				dx=Math.random();
				dy=Math.random();
				d_len = Math.sqrt(dx*dx + dy*dy);
			}
			diff = (d_len-len)/d_len;
			dx *= 0.5*diff;
			dy *= 0.5*diff;
 
			if(!p2.isMouse){
				p2.xx -= dx;
				p2.yy -= dy;
			}
			if(!p1.isMouse){
				p1.xx += dx;
				p1.yy += dy;
			}
 
		}
		// ========================================================== //
	}
 
	internal class WeakJoint extends Joint
	{
		// ========================================================== //
		public function WeakJoint(_p1:Particle, _p2:Particle, _len:Number):void{
			super(_p1,_p2,_len);
		}
 
		// ========================================================== //
		override public function Apply():void{
			var dx:Number;
			var dy:Number;
			var d_len:Number;
			var diff:Number;
 
			dx = p2.xx-p1.xx;
			dy = p2.yy-p1.yy;
			d_len = Math.sqrt(dx*dx + dy*dy);
			if(d_len==0){
				dx=Math.random();
				dy=Math.random();
				d_len = Math.sqrt(dx*dx + dy*dy);
			}
			if(d_len>len){
				diff = (d_len-len)/d_len;
				dx *= diff;
				dy *= diff;
 
				if(!p2.isMouse){
					p2.xx -= dx;
					p2.yy -= dy;
				}
				if(!p1.isMouse){
					p1.xx += dx;
					p1.yy += dy;
				}
			}
		}
 
		// ========================================================== //
	}
 
	internal class RangeJoint extends Joint
	{
		public var lenmax:Number;
		public var lenmin:Number;
		// ========================================================== //
		public function RangeJoint(_p1:Particle, _p2:Particle, _lenmin:Number, _lenmax:Number):void
		{
			lenmax=_lenmax;
			lenmin=_lenmin;
			super(_p1,_p2,_lenmax);
		}
 
		// ========================================================== //
		override public function Apply():void
		{
			var dx:Number;
			var dy:Number;
			var d_len:Number;
			var diff:Number;
 
			dx = p2.xx-p1.xx;
			dy = p2.yy-p1.yy;
			d_len = Math.sqrt(dx*dx + dy*dy);
			if(d_len==0){
				dx=Math.random();
				dy=Math.random();
				d_len = Math.sqrt(dx*dx + dy*dy);
			}
			if((d_len>lenmax)||(d_len<lenmin)){
				if(d_len>lenmax)
					diff = (d_len-lenmax)/d_len;
				if(d_len<lenmin)
					diff = (d_len-lenmin)/d_len;
				dx *= diff;
				dy *= diff;
 
				if(!p2.isMouse){
					p2.xx -= dx;
					p2.yy -= dy;
				}
				if(!p1.isMouse){
					p1.xx += dx;
					p1.yy += dy;
				}
			}
		}
		// ========================================================== //
	}

Добавлено через 12 часов 1 минуту
Вопрос ко всем, а как реализовать трение о поверхность(границы нашего квадрата). Как я понимаю, если частица "проникла" в другой объект, то надо добавить силу трения, направленную в противоположную сторону скорости.. но как это сделать? Есть ли у кого хорошие статейки по теме?

[Герыч]

Трение реализовал) но с WeakJoint связями возникают какие-то баги. Верёвка начинает сама шевелиться!

package gerich.verlet
{
	import flash.display.Shape;
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.MouseEvent;
 
	public class Main extends Sprite{
		private var pt:Array = new Array();
		private var joints:Array = new Array();
		private var particles:Sprite = new Sprite();
		private var canvas:Shape = new Shape();
		private var grav:Number = 500;
		private var friction:Number = 10;
		private var timeSqr:Number;
 
		// ========================================================== //
		public function Main():void{
			stage.frameRate = 40;
 
			timeSqr=1/stage.frameRate;timeSqr*=timeSqr;
 
			addChild(canvas);
 
			addChild(particles);
 
			pt.push(new Particle(270,150,true));
 
			for (var j:int=0;j<60;j++)
			{
				pt.push(new Particle(270,150));
				joints.push(new WeakJoint(pt[j], pt[j+1], 8));
			}
 
 
			for (var i in pt){
				particles.addChild(pt[i]);
			}
 
			addEventListener(Event.ENTER_FRAME, checkJoints);
			addEventListener(Event.ENTER_FRAME, ptMouse);
		}
		// ========================================================== //
 
		private function checkJoints(event:Event):void{
			var dx:Number;
			var dy:Number;
			var fx:Number;
			var fy:Number;
 
			canvas.graphics.clear();
 
			// Gravity
 
			for (var i in pt){
				dx = (pt[i].xx - pt[i].old_x);
				dy = (pt[i].yy - pt[i].old_y);
				pt[i].old_x = pt[i].xx;
				pt[i].old_y = pt[i].yy;
				fx=pt[i].xx+dx;
				fy=pt[i].yy+dy+grav*timeSqr;
				pt[i].xx=fx;
				pt[i].yy=fy;
				if(fx<0){
					if(dy>0)
						pt[i].old_y=Math.max(pt[i].old_y+fx*friction,pt[i].yy);
					else
						pt[i].old_y=Math.min(pt[i].old_y-fx*friction,pt[i].yy);
				}
				if(fx>stage.stageWidth){
					if(dy>0)
						pt[i].old_y=Math.max(pt[i].old_y+(stage.stageWidth-fx)*friction,pt[i].yy);
					else
						pt[i].old_y=Math.min(pt[i].old_y-(stage.stageWidth-fx)*friction,pt[i].yy);
				}
				if(fy<0){
					if(dx>0)
						pt[i].old_x=Math.max(pt[i].old_x+fy*friction,pt[i].xx);
					else
						pt[i].old_x=Math.min(pt[i].old_x-fy*friction,pt[i].xx);
				}
				if(fy>stage.stageHeight){
					if(dx>0)
						pt[i].old_x=Math.max(pt[i].old_x+(stage.stageHeight-fy)*friction,pt[i].xx);
					else
						pt[i].old_x=Math.min(pt[i].old_x-(stage.stageHeight-fy)*friction,pt[i].xx);
				}
			}
 
			// Joints
 
 
			for (var z:int=0; z<30; z++){
				for (var i in joints){
					joints[i].Apply();
				}
 
				for (var i in pt){
					pt[i].xx=Math.max(pt[i].xx,0);
					pt[i].xx=Math.min(pt[i].xx,stage.stageWidth);
					pt[i].yy=Math.max(pt[i].yy,0);
					pt[i].yy=Math.min(pt[i].yy,stage.stageHeight);
				}
			}
 
			for (var i in pt){
				pt[i].x = pt[i].xx;
				pt[i].y = pt[i].yy;
			}
			// Lines
			for (var i in joints){
				joints[i].Draw(canvas);
			}
		}
		// ========================================================== //
		private function ptMouse(event:Event):void{
			for (var i in pt){
				if(pt[i].isMouse){
					pt[i].x=mouseX;
					pt[i].y=mouseY;
					pt[i].xx=mouseX;
					pt[i].yy=mouseY;
				}
			}
			canvas.graphics.clear();
			// Lines
			for (var i in joints){
				joints[i].Draw(canvas);
			}
		}
	}
}
 
// ***** [ Particle Class ] ***************************************** //
 
	import flash.display.Sprite;
 
	internal class Particle extends Sprite{
		public var old_x:Number;
		public var old_y:Number;
		public var xx:Number;
		public var yy:Number;
		public var isMouse:Boolean;
 
		// ========================================================== //
		public function Particle(_x:int, _y:int, _isMouse:Boolean=false):void{
			x = _x;
			y = _y;
 
			xx = _x;
			yy = _y;
 
			old_x = _x;
			old_y = _y;
 
			isMouse=_isMouse;
 
			graphics.lineStyle(1, 0x000000);
			graphics.beginFill(0xFFD22B);
			graphics.drawCircle(0,0,5);
			graphics.endFill();
		}
		// ========================================================== //
	}
 
	import flash.display.Shape;
 
	internal class Joint{
		public var p1:Particle;
		public var p2:Particle;
		public var len:Number;
 
		// ========================================================== //
		public function Joint(_p1:Particle, _p2:Particle, _len:Number):void{
			p1=_p1;
			p2=_p2;
			len=_len;
		}
		// ========================================================== //
 
		public function Draw(canvas:Shape):void{
			canvas.graphics.lineStyle(1,0x000000);
			canvas.graphics.moveTo(p1.x, p1.y);
			canvas.graphics.lineTo(p2.x, p2.y);
		}
		// ========================================================== //
 
		public function Apply():void{
			var dx:Number;
			var dy:Number;
			var d_len:Number;
			var diff:Number;
 
			dx = p2.xx-p1.xx;
			dy = p2.yy-p1.yy;
			d_len = Math.sqrt(dx*dx + dy*dy);
			if(d_len==0){
				dx=Math.random();
				dy=Math.random();
				d_len = Math.sqrt(dx*dx + dy*dy);
			}
			diff = (d_len-len)/d_len;
			dx *= 0.5*diff;
			dy *= 0.5*diff;
 
			if(!p2.isMouse){
				p2.xx -= dx;
				p2.yy -= dy;
			}
			if(!p1.isMouse){
				p1.xx += dx;
				p1.yy += dy;
			}
 
		}
		// ========================================================== //
	}
 
	internal class WeakJoint extends Joint
	{
		// ========================================================== //
		public function WeakJoint(_p1:Particle, _p2:Particle, _len:Number):void{
			super(_p1,_p2,_len);
		}
 
		// ========================================================== //
		override public function Apply():void{
			var dx:Number;
			var dy:Number;
			var d_len:Number;
			var diff:Number;
 
			dx = p2.xx-p1.xx;
			dy = p2.yy-p1.yy;
			d_len = Math.sqrt(dx*dx + dy*dy);
			if(d_len==0){
				dx=Math.random();
				dy=Math.random();
				d_len = Math.sqrt(dx*dx + dy*dy);
			}
			if(d_len>len){
				diff = (d_len-len)/d_len;
				dx *= diff;
				dy *= diff;
 
				if(!p2.isMouse){
					p2.xx -= dx;
					p2.yy -= dy;
				}
				if(!p1.isMouse){
					p1.xx += dx;
					p1.yy += dy;
				}
			}
		}
 
		// ========================================================== //
	}
 
	internal class RangeJoint extends Joint
	{
		public var lenmax:Number;
		public var lenmin:Number;
		// ========================================================== //
		public function RangeJoint(_p1:Particle, _p2:Particle, _lenmin:Number, _lenmax:Number):void
		{
			lenmax=_lenmax;
			lenmin=_lenmin;
			super(_p1,_p2,_lenmax);
		}
 
		// ========================================================== //
		override public function Apply():void
		{
			var dx:Number;
			var dy:Number;
			var d_len:Number;
			var diff:Number;
 
			dx = p2.xx-p1.xx;
			dy = p2.yy-p1.yy;
			d_len = Math.sqrt(dx*dx + dy*dy);
			if(d_len==0){
				dx=Math.random();
				dy=Math.random();
				d_len = Math.sqrt(dx*dx + dy*dy);
			}
			if((d_len>lenmax)||(d_len<lenmin)){
				if(d_len>lenmax)
					diff = (d_len-lenmax)/d_len;
				if(d_len<lenmin)
					diff = (d_len-lenmin)/d_len;
				dx *= diff;
				dy *= diff;
 
				if(!p2.isMouse){
					p2.xx -= dx;
					p2.yy -= dy;
				}
				if(!p1.isMouse){
					p1.xx += dx;
					p1.yy += dy;
				}
			}
		}
		// ========================================================== //
	}

[Герыч]

Большинство багов исправил, сделал настройки всякие) прикрепляю 1-ый файл - "хорошая" версия.
Во втором файле проблемы.. когда ставлю жёсткие Joint'ы, то вся конструкция начинает вращаться.
Кто знает решение и причину проблемы, поделитесь..

[Crash512]

О... а можешь мне исходник выслать?.. Надо бы нам как-то скооперироваться, и довести это дело до конца. Мне вот нужны именно жёсткие связи=)

Я даже подумываю о том, что это пора в новую ветку выводить=))
В этой уже дофига кода, надо как-то всё в кучу собрать=)

[Герыч]

вот код