Sandy引擎学习笔记：Mode7

由于官方已经提供了这个例子，我干脆弄了一个例子上来，其实也是按它的做法来完成的。

sandy 3.1版本新增了一个类库包sandy.core.scenegraph.mode7

这个类库包里面提供了两个类，一个是Mode7，一个是CameraMode7，这两个类非常有用。Mode7常用在地面，地步一些渲染上，能够提高一些质量，比plane3D要好一些。 而CameraMode7类和Camera3D其实差不多，仅仅是他的一个子类，但是区别在于，他约束Y轴的旋转。

package
{
import flash.display.Bitmap;
import flash.display.Sprite;
import flash.events.*;
import flash.net.*;
import flash.text.*;
import flash.ui.Keyboard;

import mx.events.*;
import mx.resources.*;

import sandy.core.Scene3D;
import sandy.core.data.*;
import sandy.core.scenegraph.*;
import sandy.core.scenegraph.mode7.*;
import sandy.materials.*;
import sandy.materials.attributes.*;
import sandy.primitive.*;

[SWF(width='700',height='500',backgroundColor='0xCCBBBB',frameRate='30')]
public class Example4 extends Sprite
{
private var scenne:Scene3D;
private var camera:Camera3D;
private var ranY:Number=0.5;
private var box:Box;
private var box2:Box;
private var box3:Box;
private var plane:Plane3D;

[Embed(source="map.jpg")]
public var pic:Class;
private var bitmap:Bitmap;
private var _upPush:int;
private var _downPush:int;
private var _leftPush:int;
private var _rightPush:int;
private var _mode7:Mode7;
public function Example4()
{
bitmap=new pic() as Bitmap;

camera=new CameraMode7(700,500);
camera.x = 0;
camera.y = 100;
camera.z = 0;
camera.tilt =20;

var root:Group=createScene();
scenne=new Scene3D("scene1",this,camera,root);
addEventListener(Event.ENTER_FRAME,Run);
stage.addEventListener (KeyboardEvent.KEY_DOWN, onKey);
stage.addEventListener (KeyboardEvent.KEY_UP, onKey);

}

private function onKey (kEvt:KeyboardEvent):void
{
if (kEvt.type==KeyboardEvent.KEY_DOWN)
{
if (kEvt.keyCode==Keyboard.UP)
{
_upPush=1;
}
else if (kEvt.keyCode == Keyboard.DOWN)
{
_downPush=1;
}
else if (kEvt.keyCode == Keyboard.LEFT)
{
_leftPush=1;
trace("left");
}
else if (kEvt.keyCode == Keyboard.RIGHT)
{
_rightPush=1;
}
}
else if (kEvt.type == KeyboardEvent.KEY_UP)
{
if (kEvt.keyCode==Keyboard.UP)
{
_upPush=0;
}
else if (kEvt.keyCode == Keyboard.DOWN)
{
_downPush=0;
}
else if (kEvt.keyCode == Keyboard.LEFT)
{
_leftPush=0;
}
else if (kEvt.keyCode == Keyboard.RIGHT)
{
_rightPush=0;
}
}
}

private function createScene():Group
{
var g:Group=new Group();
box=new Box("box",50,50,50);
box.x=-20;
box.y=0;
box.z=-100;
box.rotateX=50;

box2=new Box("box2",50,50,50);
box2.x=50;
box2.y=0;
box2.z=-100;
box2.rotateX=50;

box3=new Box("box3",50,50,50);
box3.x=120;
box3.y=0;
box3.z=-100;
box3.rotateX=50;

_mode7 = new Mode7();
_mode7.setBitmap ( bitmap.bitmapData );
_mode7.setHorizon (true, 0x000000, 1);
_mode7.setNearFar (true);

g.addChild( _mode7);
g.addChild(box);
g.addChild(box2);
g.addChild(box3);
_mode7.repeatMap = false;
var materialAttr:MaterialAttributes = new MaterialAttributes(
new LineAttributes( 0.5, 0x2111BB, 0 ),
new LightAttributes( true, 0.1)
);

var material:Material = new ColorMaterial( 0x0000FF, 1, materialAttr );
var material2:Material = new ColorMaterial( 0x00FF00, 1, materialAttr );
var material3:Material = new ColorMaterial( 0xFF0000, 1, materialAttr );

material.lightingEnable = true;
material2.lightingEnable = true;
material3.lightingEnable = true;

var app:Appearance = new Appearance( material );
var app2:Appearance = new Appearance( material2 );
var app3:Appearance = new Appearance( material3 );

box.appearance = app;
box2.appearance = app2;
box3.appearance = app3;

box.container.buttonMode = true;
box2.container.buttonMode = true;
box3.container.buttonMode = true;
box.container.addEventListener(MouseEvent.CLICK, clickHandler);
box2.container.addEventListener(MouseEvent.CLICK, clickHandler2);
box3.container.addEventListener(MouseEvent.CLICK, clickHandler3);
return g;

}
private function Run(event:Event):void
{
scenne.render();
box.rotateY+=1;
box2.rotateY+=1;
box3.rotateY+=1;

camera.rotateY += (_leftPush - _rightPush) * 2;
var rotationRadian:Number=Math.PI*camera.rotateY/180;
camera.x += Math.sin(- rotationRadian) * (_upPush - _downPush) * 8;
camera.z += Math.cos(- rotationRadian) * (_upPush - _downPush) * 8;
}
private function clickHandler(event:MouseEvent):void
{

trace("第一个你点了");
navigateToURL(new URLRequest("http://www.baidu.com"),"_blank");
}
private function clickHandler2(event:MouseEvent):void
{

trace("第二个你点了我 ");
navigateToURL(new URLRequest("http://www.google.cn"),"_blank");
}
private function clickHandler3(event:MouseEvent):void
{

trace("第三个你点了我 ");
navigateToURL(new URLRequest("http://www.hao123.com"),"_blank");
}
}
}

创建一个CameraMode7 摄影机。

camera=new CameraMode7(700,500);
camera.x = 0;
camera.y = 100;
camera.z = 0;
camera.tilt =20;

创建一个Mode7对象，指定他的位图数据，由于我们是在flex里面编写，所以使用内嵌资料。指定他的位图

[Embed(source="map.jpg")]
public var pic:Class;//内嵌位图

_mode7 = new Mode7();
_mode7.setBitmap ( bitmap.bitmapData );
_mode7.setHorizon (true, 0x000000, 1);
_mode7.setNearFar (true);

其中这个程序里面使用了键盘交互，因此对其一些简单算法需要了解一下就可以。

演示地址：http://blog.5d.cn/user45/hero82748274/200903/515641.html

下载文件：http://blog.5d.cn/user45/hero82748274/upload/2009-03/Example4.rar