public void update()
        {
            float luz = calculateLight() + 0.1f;

            time += ElapsedTime;

            if (time < 0)
            {
                time = 0;
            }

            mainEffect.SetValue("time", time);
            mainEffect.SetValue("luz", luz);

            grassEffect.SetValue("time", time);
            grassEffect.SetValue("luz", luz);
            grassEffect.SetValue("wind", TgcParserUtils.vector2ToFloat2Array(MyWorld.Wind));

            treeEffect.SetValue("time", time);
            treeEffect.SetValue("luz", luz);
            treeEffect.SetValue("wind", TgcParserUtils.vector2ToFloat2Array(MyWorld.Wind));

            foreach (TgcMesh mesh in MyWorld.SkyBox.Faces)
            {
                mesh.Effect.SetValue("time", (float)time);
                mesh.Effect.SetValue("luz", luz);
            }
        }