IT妖怪

HelloAlternativa3D.as

package {
 import alternativa.engine3d.controllers.CameraController;
 import alternativa.engine3d.core.Camera3D;
 import alternativa.engine3d.core.Object3D;
 import alternativa.engine3d.core.Scene3D;
 import alternativa.engine3d.display.View;
 import alternativa.engine3d.materials.WireMaterial;
 import alternativa.engine3d.primitives.Box;
 import alternativa.utils.FPS;

 import flash.display.Sprite;
 import flash.display.StageAlign;
 import flash.display.StageScaleMode;
 import flash.events.Event;

 [SWF(backgroundColor="#000000", frameRate="100")]

 public class HelloAlternativa3D extends Sprite    {

 private var scene:Scene3D;
 private var view:View;
 private var camera:Camera3D;
 private var cameraController:CameraController;
 private var box:Box;

 public function HelloAlternativa3D()    {
 addEventListener(Event.ADDED_TO_STAGE, init);
 }

 public function init(e:Event): void {
 removeEventListener(Event.ADDED_TO_STAGE, init);

 stage.scaleMode = StageScaleMode.NO_SCALE;
 stage.align = StageAlign.TOP_LEFT;

 // Creating scene
 scene = new Scene3D();
 scene.root = new Object3D();
 box = new Box(100, 100, 100, 3, 3, 3);
 box.cloneMaterialToAllSurfaces(new WireMaterial(1, 0xFFFFFF));
 scene.root.addChild(box);

 // Adding camera and view
 camera = new Camera3D();
 camera.x = 100;
 camera.y = -150;
 camera.z = 100;
 scene.root.addChild(camera);

 view = new View();
 addChild(view);
 view.camera = camera;

 // Connecting camera controller
 cameraController = new CameraController(stage);
 cameraController.camera = camera;
 cameraController.setDefaultBindings();
 cameraController.checkCollisions = true;
 cameraController.collisionRadius = 20;
 cameraController.lookAt(box.coords);
 cameraController.controlsEnabled = true;

 // FPS display launch
 FPS.init(stage);

 stage.addEventListener(Event.RESIZE, onResize);
 stage.addEventListener(Event.ENTER_FRAME, onEnterFrame);
 onResize(null);
 }

 private function onResize(e:Event):void {
 view.width = stage.stageWidth;
 view.height = stage.stageHeight;
 }

 private function onEnterFrame(e:Event):void {
 // User input processing
 cameraController.processInput();
 // Scene calculating
 scene.calculate();
 }
 }
}

1. 创建场景

   首先我们传建一个场景并且添上一个方盒:

   // Create scene object. Scene is a container which have everything else inside.
   scene = new Scene3D();
   // Set root object for scene hierarchy. Root object coordinate system becomes scene global coordinate system.
   scene.root = new Object3D();
   // Create cube primitive
   box = new Box(100, 100, 100, 3, 3, 3);
   // Set material which draws primitive edges
   box.cloneMaterialToAllSurfaces(new WireMaterial(1, 0xFFFFFF));
   // Add primitive to a scene
   scene.root.addChild(box);
   

2. 添加摄像机
   摄像机是必不可少的东东，这一步也是不可缺少的，初学Flash 3D时，最容易出现的错误就是模型或者场景没问题，但是摄像机方向有问题或者缩放比率有问题，导致找不到错误点

   // Create camera instance and set it's coordinates
   camera = new Camera3D();
   camera.x = 100;
   camera.y = -150;
   camera.z = 100;
   // Add camera to the scene
   scene.root.addChild(camera);
   // Create a view and connect it to the camera
   view = new View();
   addChild(view);
   view.camera = camera;
   

   、

3. 控制摄像机
   在Alternativa3D中，已经提供了很多控制控制摄像机的类（这里有介绍），现在我们先挑一个 alternativa.engine3d.controllers.CameraController
   用法如下

   // Create controller and connect camera
   cameraController = new CameraController(stage);
   cameraController.camera = camera;
   // Set default control keys
   cameraController.setDefaultBindings();
   // Turn on camera collision detection
   cameraController.checkCollisions = true;
   // Set collision detection radius for camera
   cameraController.collisionRadius = 20;
   // Aim camera at the cube primitive
   cameraController.lookAt(box.coords);
   // Activate camera controls
   cameraController.controlsEnabled = true;
   

4. 最后的工作
   现在场景、摄像机、控制全都有了，我们把他们组装在一起

   public function HelloAlternativa3D() {
   
    //...
   
    // Initialize FPS display
    FPS.init(stage);
    // This function is for view size changes during player window changes
    addEventListener(Event.RESIZE, onResize);
    // This function enables user input processing and scene calculation every frame
    stage.addEventListener(Event.ENTER_FRAME, onEnterFrame);
    // Initial view size
    onResize(null);
   }
   
   private function onResize(e:Event):void {
    // Set view size equal to player window size
    view.width = stage.stageWidth;
    view.height = stage.stageHeight;
   }
   
   private function onEnterFrame(e:Event):void {
    // User input processing
    cameraController.processInput();
    // Scene calculating. Scene will be recalculated and all changes will be redrawed in camera.
    scene.calculate();
   }