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 **********

姓名王泽晶

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 /geometry/sphereline/

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

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

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

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

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

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

_position.getVec(1)) +

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

_position.getVec(2))) * 2.0;

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

if ( t1

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

else

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

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

{

draw();

}

public function draw():void{

graphics.clear();

if(txtViewDir.text == "")

return;

var ary:Array = txtViewDir.text.split(",");

var flag:Boolean = false;

for(var i:int= 0;i

{

if(ary[i] == "" || isNaN(ary[i]))

{

flag = true;

break;

}

}

if(flag)

txtViewDir.setStyle("color",0xff0000);

return;

}

txtViewDir.setStyle("color",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(ary[i] == "" || isNaN(ary[i]))

{

flag = true;

break;

}

}

if(flag)

{

txtLight.setStyle("color",0xff0000);

return;

}

txtLight.setStyle("color",0x000000);

var light:Light = new Light();

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

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

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();

}

public function drawImg():void{

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