计算机图形学实验报告-实验5Phong光照模型

1、PAGE 32PAGE 6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 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：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)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视点方向初始为(0,0,1)， 光源方向初始为(1,1,1)视口设置为x0 = -100,

2、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.get

3、Vec(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) - view

4、Start.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 + At2 = 0var delt

5、a:Number = B*B - 4*A*C;if ( delta0.0 | A=0.0 ) return false;/ We dont consider whether 0t1 here because real viewer is at infinite placevar t1:Number = (-B + Math.sqrt(delta) / (2*A);var t2:Number = (-B - Math.sqrt(delta) / (2*A);if ( t1t2 )point = viewStart.multiplyk(1.0 - t1).add(viewEnd.multiplyk

6、(t1);elsepoint = 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):vo

7、iddraw();public function draw():voidgraphics.clear();if(txtViewDir.text = )return;var ary:Array = txtViewDir.text.split(,);var flag:Boolean = false;for(var i:int= 0;iary.length;i+)if(aryi = | isNaN(aryi)flag = true;break;if(flag) txtViewDir.setStyle(color,0 xff0000);return;txtViewDir.setStyle(color,

8、0 x000000);var viewDir:Vec3 = new Vec3(Number(ary0), Number(ary1), Number(ary2);ary = txtLight.text.split(,);flag = false;for(i= 0;iary.length;i+)if(aryi = | isNaN(aryi)flag = true;break;if(flag) txtLight.setStyle(color,0 xff0000);return;txtLight.setStyle(color,0 x000000);var light:Light = new Light

9、();light.direction = new Vec3(Number(ary0), Number(ary1), Number(ary2).negative();light.ambient = new Vec3(Number(ary0), Number(ary1), Number(ary2);ensity = new Vec3(Number(ary0), Number(ary1), Number(ary2);var material:Material = new Material();material.diffuse =new Vec3(0.0, 0.0, 0.8);material.spe

10、cular =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():voidfor(var y:int = 0 ;y150;y+)for(var x:int =0;x200;x+)var index:int = (y*200 + x) * 3;var r:Number = dataindex+0;var g:Number =

11、 dataindex+1;var b:Number = dataindex+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 ):Arrayvar data:Array = new Array();data.length = width * height * 3;_width = width;_height

12、 = heightreturn data;public function createSceneImage( width:int,height: int ,viewDir:Vec3, light:Light, material:Material ):Arrayvar 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 =

13、width / 2var halfH:int = height / 2;for ( var y:int=0; yheight; +y )for ( var x:int=0; xwidth; +x )var viewStart:Vec3 = new Vec3(Number(x - halfW), Number(y - halfH), 0.0);if ( puteIntersection(viewStart, viewDir) )sphere.color = puteColor(light, viewDir, sphere.normal);elsesphere.color = new Vec3(0.1, 0.1, 0.1);var index:int = (y*width + x) * 3;dataindex+0 = (sphere.color.getVec(0) * 255.0);dataindex