public void AddEntity(Entity entity)
        {
            _entities.Add(entity);

            if (entity is RigidBodyEntity)
            {
                RigidBodyEntity rbe = (RigidBodyEntity)entity;
                World.AddBody(rbe.Body);
            }
        }
        public override void StartGame()
        {
            ////Set up some entities
            RigidBodyEntity ground = new RigidBodyEntity("ground", new Vector3(0f, -1f, 0f), VectorHelper.CreateOrientationMatrix(Vector3.Zero), Vector3.One * 0.05f, new BoxShape(new JVector(1000, 1, 1000)));

            ground.Body.IsStatic = true;
            ground.Body.Material.KineticFriction = 0.5f;
            ground.Body.EnableDebugDraw          = false;

            AddEntity(ground);


            for (int i = 0; i < 10; i++)
            {
                for (int y = 0; y < 10; y++)
                {
                    float offset;
                    if (y % 2 == 1)
                    {
                        offset = 0f;
                    }
                    else
                    {
                        offset = 5f;
                    }


                    RigidBodyEntity ship = new RigidBodyEntity("ship", new Vector3((i * 15), 100f + (y * 15f), offset), VectorHelper.CreateOrientationMatrix(Vector3.Zero), Vector3.One * 0.005f, new BoxShape(new JVector(10, 5, 10)));
                    ship.Body.Material.Restitution = 0.999999f;
                    ship.Body.Mass            = 2500f;
                    ship.Body.EnableDebugDraw = false;
                    AddEntity(ship);
                }
            }

            ////Actors.Add(new BasicActor(Models["teapot"], new Vector3(0f, 0f, 0f), Vector3.Zero, Vector3.One * 10, graphics));
            ////Actors.Add(new BasicActor(Models["teapot"], new Vector3(250f, 0f, 0f), Vector3.Zero, Vector3.One * 10, graphics));
            ////Actors.Add(new BasicActor(Models["ship"], , Vector3.Zero, Vector3.One, graphics));
        }