在前文中，我們已經實現了加載復雜的3D模型并在空間中進行控制，通常在一個游戲程序中，這樣的3D模型有很多，如果每一個都在場景中去繪制，那么Draw()方法就會很復雜了，而且也不利于代碼的復用。更好的方式是把這艘飛船實現為GameComponent，而且是DrawableGameComponent。接下來我們就來構造飛船組件。 首先為項目中添加一個新元素，使用XNA中的GameComponent，在生成的代碼中做如下修改： public class Ship :Microsoft.Xna.Framework.DrawableGameComponent 即將GameComponent改為DrawableGameComponent，然后加入Draw()方法。 public override void Draw(GameTimegameTime) 同樣使用Model model;和Matrix[] modelTransforms;兩個成員變量用于保存模型和骨骼數據。并在Initialize()方法中完成加載，代碼見下：? ~~~ public override void Initialize() { model = Game.Content.Load<Model>(@"Models/wedge_player1"); modelTransforms = new Matrix[model.Bones.Count]; base.Initialize(); } ~~~ 但是經過這樣的封裝以后，使用者無法進行坐標變換的控制了，因此，還需要提供三個用于坐標變換的矩陣。加入成員變量：? ~~~ public Matrix worldMatrix {set;get;} public Matrix viewMatrix { set; get; } public Matrix projectionMatrix { set; get; } ~~~ 最后完成Draw()方法，代碼如下：? ~~~ public override void Draw(GameTime gameTime) { //GraphicsDevice.Clear(Color.CornflowerBlue); model.CopyAbsoluteBoneTransformsTo(modelTransforms); foreach (ModelMesh mesh in model.Meshes) { foreach (BasicEffect effect in mesh.Effects) { effect.EnableDefaultLighting(); effect.World = modelTransforms[mesh.ParentBone.Index] * worldMatrix; effect.View = viewMatrix; effect.Projection = projectionMatrix; } mesh.Draw(); } base.Draw(gameTime); } ~~~ 這樣，這個Ship類就封裝完成了，當在場景中使用時，需要創建一個ship對象： ship = new Ship(this); 然后將其加到Components中去： Components.Add(ship); 并在LoadContent()方法中為其指定變換參數：? ~~~ ship.projectionMatrix = camera.projection; ship.viewMatrix = camera.view * Matrix.CreateTranslation(new Vector3(4, 0, 10)); ship.worldMatrix = Matrix.CreateScale(-0.02f) * Matrix.CreateRotationZ(MathHelper.ToRadians(180))*Matrix.CreateTranslation(new Vector3(20,0,0)); ~~~ 當然也可以同樣在Update()方法中更新ship.worldMatrix以對其進行旋轉、平移、縮放的操作。如果需要有多艘飛船的編隊，只要多創建幾個ship對象，分別為其設定到不同的坐標即可。這樣一來，通過繼承自GameCompenent進行游戲組件的封裝，可以在代碼的可復用性上取得收益。 好了，我們已經有了更豐富的物體了，多生成幾艘飛船試試，看看編隊是否夠壯觀吧。  附Ship類的源代碼：? ~~~ public class Ship : Microsoft.Xna.Framework.DrawableGameComponent { public Matrix worldMatrix {set;get;} public Matrix viewMatrix { set; get; } public Matrix projectionMatrix { set; get; } Model model; Matrix[] modelTransforms; public Ship(Game game) : base(game) { worldMatrix = Matrix.Identity; viewMatrix = Matrix.Identity; projectionMatrix = Matrix.Identity; } /// <summary> /// Allows the game component to perform any initialization it needs to before starting /// to run. This is where it can query for any required services and load content. /// </summary> public override void Initialize() { model = Game.Content.Load<Model>(@"Models/wedge_player1"); modelTransforms = new Matrix[model.Bones.Count]; base.Initialize(); } /// <summary> /// Allows the game component to update itself. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> public override void Update(GameTime gameTime) { base.Update(gameTime); } public override void Draw(GameTime gameTime) { //GraphicsDevice.Clear(Color.CornflowerBlue); model.CopyAbsoluteBoneTransformsTo(modelTransforms); foreach (ModelMesh mesh in model.Meshes) { foreach (BasicEffect effect in mesh.Effects) { effect.EnableDefaultLighting(); effect.World = modelTransforms[mesh.ParentBone.Index] * worldMatrix; effect.View = viewMatrix; effect.Projection = projectionMatrix; } mesh.Draw(); } base.Draw(gameTime); } } ~~~ ——歡迎轉載，請注明出處 [http://blog.csdn.net/caowenbin](http://blog.csdn.net/caowenbin) ——