计算机图形学实验报告-实验5Phong光照模型

计算机图形学 实验报告

班级 计算机工硕班 学号 2011220456 姓名 王泽晶

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实验五: Phong光照模型

实验目的

通过本次试验，学生可以掌握简单光照明模型的计算，以及真实感绘制中三维场景搭建的初步知识。

实验内容：

对给定的光源、相机状态，对球进行Phong光照明模型绘制。

搭建三维场景：

a) 在三维空间中摆放1个球，半径为R，默认为50 ，摆放位置为(0,0,0) b) 球的材质默认值为Ka = (0.1,0.1,0.1), Kd = (0,0,0.8), Ks = 0.2, n = 10 c) 视点方向初始为(0,0,1)， 光源方向初始为(1,1,1) d) 视口设置为x0 = -100, y0 = -75, w = 200, h = 150

使用phong模型绘制场景

试验步骤：

添加成员函数，编写成员数代码为

override public function computeIntersection( viewStart:Vec3, viewDir:Vec3):Boolean {

// See http://paulbourke.net/geometry/sphereline/

var viewEnd:Vec3 = viewStart.add(viewDir);

var A:Number = Math.pow(viewEnd.getVec(0) - viewStart.getVec(0), 2)

Math.pow(viewEnd.getVec(2) - viewStart.getVec(2), 2);

+Math.pow(viewEnd.getVec(1) - viewStart.getVec(1), 2) +

var B:Number =((viewEnd.getVec(0) - viewStart.getVec(0)) * (viewStart.getVec(0)

(viewEnd.getVec(1) - viewStart.getVec(1)) * (viewStart.getVec(1) - (viewEnd.getVec(2) - viewStart.getVec(2)) * (viewStart.getVec(2) -

- _position.getVec(0)) + _position.getVec(1)) + _position.getVec(2))) * 2.0;

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}

var C:Number = Math.pow(_position.getVec(0) - viewStart.getVec(0), 2) +

Math.pow(_position.getVec(1) - viewStart.getVec(1), 2) +

Math.pow(_position.getVec(2) - viewStart.getVec(2), 2) - _radius*_radius;

// Solve C + Bt + At^2 = 0

var delta:Number = B*B - 4*A*C;

if ( delta<0.0 || A==0.0 ) return false;

// We don't consider whether 0

var t1:Number = (-B + Math.sqrt(delta)) / (2*A); var t2:Number = (-B - Math.sqrt(delta)) / (2*A); if ( t1

point = viewStart.multiplyk(1.0 - t1).add(viewEnd.multiplyk(t1)); point = viewStart.multiplyk(1.0 - t2).add(viewEnd.multiplyk(t2)); else

normal = Vec3.normalize(point.minus(_position)); return true;

public var _width :Number =0.0; public var _height:Number = 0.0; public var data:Array = new Array();

protected function group1_creationCompleteHandler(event:FlexEvent):void { }

public function draw():void{

graphics.clear();

if(txtViewDir.text == \)

var ary:Array = txtViewDir.text.split(\); var flag:Boolean = false;

for(var i:int= 0;i

if(flag)

if(ary[i] == \ || isNaN(ary[i])) { }

flag = true; break; return; draw();

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}

{ }

txtViewDir.setStyle(\,0x000000);

var viewDir:Vec3 = new Vec3(Number(ary[0]), Number(ary[1]), Number(ary[2]));

ary = txtLight.text.split(\); flag = false;

for(i= 0;i

if(flag) { }

txtLight.setStyle(\,0x000000);

var light:Light = new Light();

light.direction = new Vec3(Number(ary[0]), Number(ary[1]),

light.ambient = new Vec3(Number(ary[0]), Number(ary[1]), Number(ary[2])); light.intensity = new Vec3(Number(ary[0]), Number(ary[1]), Number(ary[2]));

var material:Material = new Material(); material.diffuse =new Vec3(0.0, 0.0, 0.8); material.specular =new Vec3(0.2, 0.2, 0.2); material.ambient =new Vec3(0.1, 0.1, 0.1);

data = createSceneImage( 200, 150, viewDir, light, material ); drawImg();

txtLight.setStyle(\,0xff0000); return;

if(ary[i] == \ || isNaN(ary[i])) { }

flag = true; break;

txtViewDir.setStyle(\,0xff0000); return;

Number(ary[2])).negative();

public function drawImg():void{

for(var y:int = 0 ;y<150;y++)

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}

{ }

for(var x:int =0;x<200;x++){ }

var index:int = (y*200 + x) * 3; var r:Number = data[index+0]; var g:Number = data[index+1]; var b:Number = data[index+2];

var cl:uint =(r << 16) | (g << 8) | b; this.graphics.beginFill(cl) this.graphics.drawCircle(x,y,1); this.graphics.endFill();

public function allocateBuffer( width:int,height: int ):Array { }

public function createSceneImage( width:int,height: int , {

var data:Array = new Array();

var sphere:SphereObject = new SphereObject(50.0); sphere.setPosition(new Vec3(0.0, 0.0, 0.0) ); sphere.setMaterial( material );

var halfW:int = width / 2 var halfH:int = height / 2; for ( var y:int=0; y

for ( var x:int=0; x

var viewStart:Vec3 = new Vec3(Number(x - halfW), Number(y - halfH), 0.0);

if ( sphere.computeIntersection(viewStart, viewDir) )

var index:int = (y*width + x) * 3;

sphere.color = sphere.computeColor(light, viewDir, sphere.normal); sphere.color = new Vec3(0.1, 0.1, 0.1); else

viewDir:Vec3, light:Light, material:Material ):Array var data:Array = new Array(); data.length = width * height * 3; _width = width; _height = height return data;

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}

}

}

data[index+0] = (sphere.color.getVec(0) * 255.0); data[index+1] = (sphere.color.getVec(1) * 255.0); data[index+2] = (sphere.color.getVec(2) * 255.0);

return data;

protected function button1_clickHandler(event:MouseEvent):void { // TODO Auto-generated method stub

draw();

}

编译运行得到如下结果：

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