經過前兩節的學習，我們已經具備了創建三維空間的條件了，相信很多人已經躍躍欲試了，接下來，我們就動手開始在Windows Phone中的3D開發之旅。 打開Visual Studio 2010（什么？還沒有Windows Phone的開發環境？唉，自己處理一下吧，有問題問[百度](http://www.baidu.com)），新建一個項目（File->New->Project），在彈出的對話框中選擇XNA Game Studio 4.0中的Windows Phone Game，在Name中就命名為“Hello”吧，點擊“OK”確定。界面如下圖所示。  在Solution Explorer窗口中右擊項目名，執行Add->Class菜單項，如下圖所示。  在彈出的對話框中按下圖選擇，將類命名為Camera，點擊“Add”按鈕。  為Camera類添加兩個屬性： public Matrix view{get;protected set;} public Matrix projection { get; protectedset; } 修改Camera類的構造函數為： ~~~ public Camera(Game game, Vector3 pos,Vector3 target, Vector3 up, float fieldOfView, float aspectRatio, floatnearPlaneDistance,float farPlaneDistance) ?????????? : base(game) ?????? { ?????????? view = Matrix.CreateLookAt(pos,target, up); ?????????? projection =Matrix.CreatePerspectiveFieldOfView(fieldOfView,aspectRatio,nearPlaneDistance,farPlaneDistance); ?????? } ~~~ 該類的完整代碼見《[在Windows Phone中進行3D開發之二攝像機](http://blog.csdn.net/caowenbin/article/details/6871332)》一文。 ????? 打開Game1類，添加如下成員變量： ?????? Camera camera; ?????? Matrix world = Matrix.Identity; ?????? BasicEffect basicEffect; 在Game1()構造方法中添加代碼： graphics.IsFullScreen =true; 在LoacContent()方法中添加代碼： ~~~ ?????????? camera = new Camera(this, newVector3(0, 0, 5), Vector3.Zero, Vector3.Up, MathHelper.PiOver4,GraphicsDevice.Viewport.AspectRatio, 1.0f, 50.0f); ?????????? Components.Add(camera); ?????????? basicEffect = newBasicEffect(GraphicsDevice); ~~~ 這段代碼中，MathHelper是一個數學上的輔助類，其PiOver4屬性是π/4，即45度角。Viewport.AspectRatio是長寬比。 在Draw()方法中添加代碼： ~~~ ?????????? basicEffect.World = world; ?????????? basicEffect.View = camera.view; ?????????? basicEffect.Projection =camera.projection; ?????????? foreach (EffectPass pass inbasicEffect.CurrentTechnique.Passes) ?????????? { ?????????????? pass.Apply(); ?????????? } ~~~ BasicEffect類的作用是控制渲染效果，在3D開發中必不可少。通常用在Draw()方法中進行設置以改變渲染器的行為，后文中我們還將用它控制顏色、光線等很多特效。在前幾節內容中用的較多的就是BasicEffect的三個屬性，即代碼中的World、View、Projection，分別代表世界矩陣、攝像機矩陣、投影矩陣。這里我們要在坐標原點繪制對象，所以World設置了單位矩陣，即Mathix.Identity。 BasicEffect里包含一些Technique，每個Technique又由若干EffectPass組成，我們要在每個EffectPass上進行Apply請求，才能在該EffectPass上進行繪制。這個Apply()方法的調用就像我們進行2D時調用SpriteBatch.Begin()一樣，是繪制開始前必須調用的方法。因此在使用BasicEffect時，需要一個foreach循環。 完整的Game1類代碼如下： ~~~ using System; using System.Collections.Generic; using System.Linq; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Audio; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.GamerServices; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; using Microsoft.Xna.Framework.Input.Touch; using Microsoft.Xna.Framework.Media; namespace Hello { /// <summary> /// This is the main type for your game /// </summary> public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; Camera camera; Matrix world = Matrix.Identity; BasicEffect basicEffect; public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; // Frame rate is 30 fps by default for Windows Phone. TargetElapsedTime = TimeSpan.FromTicks(333333); // Extend battery life under lock. InactiveSleepTime = TimeSpan.FromSeconds(1); graphics.IsFullScreen = true; } /// <summary> /// Allows the game to perform any initialization it needs to before starting to run. /// This is where it can query for any required services and load any non-graphic /// related content. Calling base.Initialize will enumerate through any components /// and initialize them as well. /// </summary> protected override void Initialize() { // TODO: Add your initialization logic here base.Initialize(); } /// <summary> /// LoadContent will be called once per game and is the place to load /// all of your content. /// </summary> protected override void LoadContent() { camera = new Camera(this, new Vector3(0, 0, 5), Vector3.Zero, Vector3.Up, MathHelper.PiOver4, GraphicsDevice.Viewport.AspectRatio, 1.0f, 50.0f); Components.Add(camera); basicEffect = new BasicEffect(GraphicsDevice); } /// <summary> /// UnloadContent will be called once per game and is the place to unload /// all content. /// </summary> protected override void UnloadContent() { // TODO: Unload any non ContentManager content here } /// <summary> /// Allows the game to run logic such as updating the world, /// checking for collisions, gathering input, and playing audio. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Update(GameTime gameTime) { // Allows the game to exit if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed) this.Exit(); // TODO: Add your update logic here base.Update(gameTime); } /// <summary> /// This is called when the game should draw itself. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); basicEffect.World = world; basicEffect.View = camera.view; basicEffect.Projection = camera.projection; foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); } base.Draw(gameTime); } } } ~~~ 運行程序，打開模擬器，運行結果如下圖所示。  不用懷疑，雖然屏幕上什么都沒有，但事實上屏幕上所表現的已經是一個三維空間，我們有一個攝像機位于(0,0,5)位置，也就是屏幕外，攝像機方向指向了原點，使用了45度視角和屏幕的寬高比進行成像，近平面是1，遠平面是50。在下節中，我們就將在其中加入物體。 ——歡迎轉載，請注明出處 [http://blog.csdn.net/caowenbin](http://blog.csdn.net/caowenbin) ——