diff --git a/game-lib.js b/game-lib.js
index 0b6569f..286f076 100644
--- a/game-lib.js
+++ b/game-lib.js
@@ -1152,25 +1152,28 @@ GameLib.D3.Physics.Engine.TYPE_GOBLIN = 0x3;
 GameLib.D3.Physics.World = function(
     id,
     name,
-    engine,
-    gravity,
-    rigidBodies
+    engineType,
+    gravity
 ) {
     this.id = id;
 
     this.name = name;
 
-    this.engine = engine;
+    this.engineType = engineType;
 
-    if (typeof gravity == 'undefined'){
-        gravity = 9.8;
+    if (typeof gravity == 'undefined') {
+        gravity = new THREE.Vector3(0, -9.81, 0);
     }
     this.gravity = gravity;
 
-    if (typeof rigidBodies == 'undefined'){
-        rigidBodies = [];
+    this.worldObject = null;
+
+    if(this.engineType === GameLib.D3.Physics.Engine.TYPE_CANNON) {
+        this.worldObject = new CANNON.World();
+        this.worldObject.gravity.set(this.gravity.x, this.gravity.y, this.gravity.z);
+        this.worldObject.broadphase = new CANNON.NaiveBroadphase();
+        this.worldObject.solver.iterations = 10;
     }
-    this.rigidBodies = rigidBodies;
 };
 
 /**
@@ -2644,7 +2647,31 @@ GameLib.D3.prototype.loadScene = function(gameLibScene, onLoaded, computeNormals
 // Physics
 // ---------------
 
-GameLib.D3.Physics.World.GetIndexedVertices = function(
+GameLib.D3.Physics.World.prototype.AddRigidBody = function(
+    body
+) {
+    if(this.engineType == GameLib.D3.Physics.Engine.TYPE_CANNON) {
+        this.worldObject.addBody(body);
+    }
+};
+
+GameLib.D3.Physics.World.prototype.AddVehicle = function(
+    vehicle
+) {
+    if(this.engineType == GameLib.D3.Physics.Engine.TYPE_CANNON) {
+        vehicle.addToWorld(this.worldObject);
+    }
+};
+
+GameLib.D3.Physics.World.prototype.Step = function(
+    timeStep
+) {
+    if(this.engineType == GameLib.D3.Physics.Engine.TYPE_CANNON) {
+        this.worldObject.step(timeStep);
+    }
+};
+
+GameLib.D3.Physics.World.prototype.GetIndexedVertices = function(
    triangleMeshShape
 ) {
 
@@ -2662,7 +2689,7 @@ GameLib.D3.Physics.World.GetIndexedVertices = function(
 
 };
 
-GameLib.D3.Physics.World.GenerateWireframeViewMesh = function(
+GameLib.D3.Physics.World.prototype.GenerateWireframeViewMesh = function(
     triangleMeshShape,
     normalLength,
     scale,
@@ -2721,7 +2748,7 @@ GameLib.D3.Physics.World.GenerateWireframeViewMesh = function(
     return wireframeTHREEMesh;
 };
 
-GameLib.D3.Physics.World.GenerateTriangleCollisionMesh = function(
+GameLib.D3.Physics.World.prototype.GenerateTriangleCollisionMesh = function(
     threeMesh,
     mass,                       // default = 0
     friction,                   // default = 10
@@ -2795,6 +2822,158 @@ GameLib.D3.Physics.World.GenerateTriangleCollisionMesh = function(
     }
 };
 
+// -----------
+// SkyBox
+// -----------
+
+GameLib.D3.SkyBox = function (
+
+) {
+    this.id = null;
+    this.texturesFolder = null;
+};
+
+GameLib.D3.SkyBox.prototype.Load = function (
+    texturesFolder
+) {
+    this.texturesFolder = texturesFolder;
+    this.textures = [];
+    this.materials = [];
+    this.mesh = {};
+    this.scene = new THREE.Scene();
+    this.textureCube = null;
+
+    var textureLoader = new THREE.TextureLoader();
+
+    // this textures are used to display the skybox
+    this.textures.push(textureLoader.load(this.texturesFolder + "px.png"));
+    this.textures.push(textureLoader.load(this.texturesFolder + "nx.png"));
+    this.textures.push(textureLoader.load(this.texturesFolder + "py.png"));
+    this.textures.push(textureLoader.load(this.texturesFolder + "ny.png"));
+    this.textures.push(textureLoader.load(this.texturesFolder + "pz.png"));
+    this.textures.push(textureLoader.load(this.texturesFolder + "nz.png"));
+
+    // assign textures to each cube face
+    for (var i = 0; i < 6; i ++) {
+        this.materials.push(new THREE.MeshBasicMaterial({ map: this.textures[i] }));
+    }
+
+    // create cube geometry
+    this.mesh = new THREE.Mesh(new THREE.CubeGeometry(1, 1, 1), new THREE.MeshFaceMaterial(this.materials));
+    this.mesh.applyMatrix(new THREE.Matrix4().makeScale(1, 1, -1));
+    this.scene.add(this.mesh);
+
+    // Load env textureCube
+    // this is used for reflections on meshes
+    // mesh.material.envMap = this.textureCube;
+    this.textureCube = new THREE.CubeTextureLoader().load([
+        this.texturesFolder + "px.png", this.texturesFolder + "nx.png",
+        this.texturesFolder + "py.png", this.texturesFolder + "ny.png",
+        this.texturesFolder + "pz.png", this.texturesFolder + "nz.png"
+    ]);
+};
+
+GameLib.D3.SkyBox.prototype.Render = function (
+    threeRenderer,
+    threeCamera
+) {
+    var cameraPosition = new THREE.Vector3(threeCamera.position.x, threeCamera.position.y, threeCamera.position.z);
+
+    threeCamera.position.set(0, 0, 0);
+
+    var gl = threeRenderer.context;
+
+    gl.disable(gl.DEPTH_TEST);
+
+    threeRenderer.render(this.scene, threeCamera);
+
+    gl.enable(gl.DEPTH_TEST);
+
+    threeCamera.position.copy(cameraPosition);
+};
+
+
+// ---------
+// Game
+// ---------
+GameLib.D3.Game = function (
+
+) {
+    this.scenes = {};
+    this.physicsWorlds = [];
+    this.sceneToPhysicsWorldsMap = {};
+};
+
+GameLib.D3.Game.prototype.AddScene = function(
+    scene
+) {
+    this.scenes[scene.name] = scene;
+};
+
+GameLib.D3.Game.prototype.AddPhysicsWorld = function(
+    physicsWorld
+) {
+    this.physicsWorlds.push(physicsWorld);
+};
+
+GameLib.D3.Game.prototype.LinkPhysicsWorldToScene = function(
+    physicsWorld,
+    scene
+) {
+    this.sceneToPhysicsWorldsMap[scene.name] = this.sceneToPhysicsWorldsMap[scene.name] || [];
+    this.sceneToPhysicsWorldsMap[scene.name].push(physicsWorld);
+};
+
+GameLib.D3.Game.prototype.GetPhysicsWorldsForScene = function (
+    scene
+) {
+    return this.sceneToPhysicsWorldsMap[scene.name];
+};
+
+GameLib.D3.Game.prototype.ProcessPhysics = function (
+    timestep
+) {
+    for(var s in this.sceneToPhysicsWorldsMap) {
+
+        var physicsWorldArray = this.sceneToPhysicsWorldsMap[s];
+        var scene = this.scenes[s];
+
+        if(scene && physicsWorldArray) {
+
+            for(var i = 0, l = physicsWorldArray.length; i < l; i++) {
+
+                var physicsWorld = physicsWorldArray[i];
+                physicsWorld.Step(timestep);
+
+                for(var p in physicsWorld.linkedPairs) {
+                    var pair = physicsWorld.linkedPairs[p];
+                    var mesh = pair.threeMesh;
+                    var body = pair.physicsBody;
+
+                    if(mesh) {
+                        mesh.position.copy(body.position);
+                        mesh.quaternion.copy(body.quaternion);
+                    }
+                }
+            }
+        }
+
+    }
+};
+
+GameLib.D3.Game.prototype.LinkPair = function (
+    threeMesh,
+    physicsBody,
+    physicsWorld
+) {
+    physicsWorld.linkedPairs = physicsWorld.linkedPairs || [];
+
+    physicsWorld.linkedPairs.push({
+        threeMesh : threeMesh,
+        physicsBody : physicsBody
+    });
+};
+
 if (typeof module != 'undefined') {
     module.exports = GameLib.D3;
 }
\ No newline at end of file