improved Example.car using pin constraint

examples/car.js

@@ -42,10 +42,10 @@ Example.car = function() {
     ]);
 
     var scale = 0.9;
-    World.add(world, Composites.car(150, 100, 100 * scale, 40 * scale, 30 * scale));
+    World.add(world, Composites.car(150, 100, 150 * scale, 30 * scale, 30 * scale));
     
     scale = 0.8;
-    World.add(world, Composites.car(350, 300, 100 * scale, 40 * scale, 30 * scale));
+    World.add(world, Composites.car(350, 300, 150 * scale, 30 * scale, 30 * scale));
     
     World.add(world, [
         Bodies.rectangle(200, 150, 400, 20, { isStatic: true, angle: Math.PI * 0.06 }),

src/factory/Composites.js

@@ -239,53 +239,53 @@ var Bodies = require('./Bodies');
      */
     Composites.car = function(xx, yy, width, height, wheelSize) {
         var group = Body.nextGroup(true),
-            wheelBase = -20,
+            wheelBase = 20,
             wheelAOffset = -width * 0.5 + wheelBase,
             wheelBOffset = width * 0.5 - wheelBase,
             wheelYOffset = 0;
     
         var car = Composite.create({ label: 'Car' }),
-            body = Bodies.trapezoid(xx, yy, width, height, 0.3, { 
+            body = Bodies.rectangle(xx, yy, width, height, { 
                 collisionFilter: {
                     group: group
                 },
-                friction: 0.01,
                 chamfer: {
-                    radius: 10
-                }
+                    radius: height * 0.5
+                },
+                density: 0.0002
             });
     
         var wheelA = Bodies.circle(xx + wheelAOffset, yy + wheelYOffset, wheelSize, { 
             collisionFilter: {
                 group: group
             },
-            friction: 0.8,
-            density: 0.01
+            friction: 0.8
         });
                     
         var wheelB = Bodies.circle(xx + wheelBOffset, yy + wheelYOffset, wheelSize, { 
             collisionFilter: {
                 group: group
             },
-            friction: 0.8,
-            density: 0.01
+            friction: 0.8
         });
                     
         var axelA = Constraint.create({
-            bodyA: body,
-            pointA: { x: wheelAOffset, y: wheelYOffset },
-            bodyB: wheelA,
-            stiffness: 0.2,
+            bodyB: body,
+            pointB: { x: wheelAOffset, y: wheelYOffset },
+            bodyA: wheelA,
+            stiffness: 1,
+            length: 0,
             render: {
                 lineWidth: 0
             }
         });
                         
         var axelB = Constraint.create({
-            bodyA: body,
-            pointA: { x: wheelBOffset, y: wheelYOffset },
-            bodyB: wheelB,
-            stiffness: 0.2,
+            bodyB: body,
+            pointB: { x: wheelBOffset, y: wheelYOffset },
+            bodyA: wheelB,
+            stiffness: 1,
+            length: 0,
             render: {
                 lineWidth: 0
             }