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322 lines
10 KiB
322 lines
10 KiB
4 years ago
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<script src=lib1.js></script>
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<script src="https://pagecdn.io/lib/ace/1.4.12/ace.js" crossorigin="anonymous"></script>
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<script src="https://pagecdn.io/lib/ace/1.4.12/ext-language_tools.js" crossorigin="anonymous"></script>
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<style>
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.ace_gutter-layer {
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/* original width is 48px */
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width: 25px !important;
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}
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.ace_gutter-layer > * {
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/* 48 - 32 = 16 */
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margin-left: 0;
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}
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.ace_gutter-cell {
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padding-left: 0 !important;
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padding-right: 3px !important;
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}
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.code{
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font-family: "monaco, menlo, ubuntu mono, consolas, source-code-pro" ;
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}
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</style>
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<body bgcolor=white text=black link=black alink=blue vlink=blue>
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<center>
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<canvas id='canvas1' width=600 height=600></canvas>
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</center>
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</body>
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<!!-------- VERTEX SHADER: YOU PROBABLY DON'T WANT TO CHANGE THIS RIGHT NOW -------->
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<script id='my_vertex_shader' type='x-shader/x-vertex'>
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attribute vec3 aPos;
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varying vec3 vPos;
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void main() {
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gl_Position = vec4(aPos, 1.);
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vPos = aPos;
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}
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</script>
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<!!-------- FRAGMENT SHADER: THIS IS WHERE YOU WILL DO YOUR WORK -------->
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<script id='my_fragment_shader' type='x-shader/x-fragment'>
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uniform float uTime; // TIME, IN SECONDS
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varying vec3 vPos; // -1 < vPos.x < +1
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// -1 < vPos.y < +1
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// vPos.z == 0
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uniform sampler2D uSampler;
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// YOU MUST DEFINE A main() FUNCTION.
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void main() {
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////////////////////////////////////////////////
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//
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// HERE, FOR YOUR HOMEWORK, YOU CAN WRITE ANY
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// CODE YOU LIKE
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//DEFINE A COLOR FOR THIS FRAGMENT.
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// LIGHT DIRECTION AND COLOR
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vec3 LDir = vec3(1, 1, 1);
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vec3 LCol = vec3(1.,.98,.9);
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vec3 VDir = vec3(0., 0., 1.);
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float R = 0.5 + 0.3*sin(uTime/10.);
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// vPos IS THE 3D LOCATION OF THIS FRAGMENT.
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// SURFACE REFLECTANCE PROPERTIES
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vec3 diffuse = vec3(.7,.7,.6);
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vec3 ambient = vec3(.1,.1,.09);
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vec3 specular = vec3(.35,.35,.3);
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// CREATE A WACKY BACKGROUND PATTERN.
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vec3 color = vec3(.5 + .5 * sin(20. * vPos.x + sin(10. * vPos.y + 5. * uTime)),
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.5,
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.5 + .5 * sin(20. * vPos.y + sin(10. * vPos.x + 5. * uTime)));
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vec3 specularlight; //specular light should disregard object color.
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float x = vPos.x;
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float y = vPos.y;
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// CREATE BOUNCING ANIMATION.
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y += .5 - 2. * abs(.5 * sin(uTime));
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// FIGURE OUT WHETHER THIS PIXEL IS ON THE SPHERE.
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float rr = x * x + y * y;
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// IF SO, THEN SHADE THE SPHERE.
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if (rr < R*R) {
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// COMPUTE THE z AND NORMAL OF THE SPHERE.
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float z = R * sqrt(1. - rr/(R*R));
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vec3 N = vec3(x,y,z) / R;
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// APPLY SHADING AND LIGHTING.
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vec3 realVPos = vec3(vPos.x, vPos.y, z);
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//*DIRECTIONS ARE NORMALIZED TO GET THE CORRECT PHONG LIGHTING
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LDir = normalize(LDir - realVPos);
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VDir = normalize(VDir - realVPos);
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vec3 lcolor = ambient;
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lcolor += diffuse * max(0., dot(N, LDir)) * LCol;
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//*SPECULAR LIGHTS ARE ADDED
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specularlight = specular *
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max(0., pow(dot(2.*dot(N, LDir) * N - LDir, VDir),3.)) * LCol;
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// ROTATE THE TEXTURE OVER TIME.
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float angle = 0.4 * uTime;
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float px = cos(angle) * N.x + sin(angle) * N.z;
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float pz = -sin(angle) * N.x + cos(angle) * N.z;
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vec3 P = vec3(px, N.y, pz);
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// APPLY PROCEDURAL NOISE TEXTURE.
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float cloud = min(0.85, max(-0.05, 2. * noise(1.1 * P)));
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//const float rspeed = 10.;
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//*CALCULATING THE TEXTURE COORDINATE.
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const float pi = 3.14159265359;
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float tex_x = acos(abs(x)/sqrt(R*R-y*y));
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if(x > 0.)
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tex_x = pi - tex_x;
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tex_x = R * tex_x;
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tex_x *= 1.5708;//*Correct aspect ratio of texture 2:1 -> 2pir:2r
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tex_x = tex_x + float(uTime)*R;
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float _2pir = 2. * pi * R;
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float quo = float(int(tex_x/_2pir));
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tex_x = (tex_x - quo * _2pir) / _2pir;
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//*TEXTURE MAPPING
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color = lcolor *
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(cloud + texture2D(uSampler, vec2(tex_x, ((R - y)/(2.*R)))).xyz) + specularlight;
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}
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//*CALCULATING LIGHTING AND SHADOWS FOR THE BACKGROUND
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else{
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vec3 realVPos = vec3(vPos.x, vPos.y, -1.);
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vec3 N = vec3(0., 0., 1.);
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vec3 C = vec3(0., vPos.y - y, 0.);
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// APPLY SHADING AND LIGHTING.
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vec3 lcolor = 6.*ambient;
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//*CALCULATING DISTANCE BETWEEN SPHERE CENTER TO THE RAY
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//BETWEEN THE POINT TO LIGHT SOURCE
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vec3 LV = realVPos - LDir;
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vec3 LC = C - LDir;
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vec3 VC = C - realVPos;
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float lLV = dot(LV, LV);
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float lLC = dot(LC, LC);
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float lVC = dot(VC, VC);
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float RR = R*R;
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float d_VCVL = -dot(VC, LV);
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float dist = min(lLC, lVC);
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if (d_VCVL > 0.)
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dist = min(dist, lVC - d_VCVL*d_VCVL/lLV);
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//*CALCULATE DISTANCE BETWEEN SPHERE CENTER TO THE RAY BETWEEN POINT TO CAMERA
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vec3 EV = realVPos - VDir;
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vec3 EC = C - VDir;
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float lEV = dot(EV, EV);
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float lEC = dot(EC, EC);
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float d_VCVE = -dot(VC, EV);
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float dist2 = min(lEC, lVC);
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if (d_VCVE > 0.)
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dist2 = min(dist2, lVC - d_VCVE*d_VCVE/lEV);
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//*AMBIENT LIGHT WILL DECAY WHEN BACKGROUND POINT IS CLOSER TO THE SPHERE
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//*FIRST THE DISTANCE IS NORMALIZED, THEN I CURVED IT WITH LOGISTIC FUNCTION
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float aratio0 = 1./(1.+pow(2.71828,15.*(.2-(sqrt(lVC) - R - .4806)/1.381)));
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lcolor *= aratio0;
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diffuse *= pow(aratio0, 0.3);
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//*TEST IF CAMERA CAN SEE THE POINT
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if(dist2 < RR)
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{
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specular *= 0.;
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float d = sqrt(dist2);
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float ratio = pow(2., sqrt(dist2)/R) - 1.;
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diffuse *= ratio;
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}
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//*TEST IF THE LIGHT CAN REACH THE BACKGROUND POINT DIRECTLY
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if(dist < RR)
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{
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specular *= 0.;
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float ratio = pow(2.7, sqrt(dist)/R) - 1.7;
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float aratio = pow(2., sqrt(dist)/R) - 1.;
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if(ratio < 0.)
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ratio = 0.;
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diffuse *= ratio;
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lcolor *= aratio;
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}
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LDir = normalize(LDir - realVPos);
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VDir = normalize(VDir - realVPos);
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lcolor += 1.2*diffuse * max(0., dot(N, LDir)) * LCol;
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specularlight = 0.3*specular *
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max(0., pow(dot(2.*dot(N, LDir) * N - LDir, VDir),32.)) * LCol;
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color = color * lcolor + specularlight;
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}
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// APPLY GAMMA CORRECTION AND SET THE PIXEL COLOR.
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gl_FragColor = vec4(sqrt(color), 1.0);
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}
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</script>
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<!!-------- CREATE A PROPERLY DESCRIPTIVE TITLE BELOW -------->
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<script id='my_title' type='text/html'>
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The Bouncing Earth
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</script>
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<!!-------- HERE IS WHERE YOU CAN PROVIDE A LONGER TEXT DESCRIPTION -------->
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<script id='my_instructions' type='text/html'><font color=#909090>
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<p style="font-size:30px; ">This is a description
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of my cool homework
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that you are seeing now.</p>
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<p>
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<i style="font-size:25px;">Here is how it works:</i>
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<ul>
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<li>First, I added <a href="http://planetpixelemporium.com/download/download.php?earthmap1k.jpg">texture</a> to the sphere. The code to load the texture is from
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<a href="https://developer.mozilla.org/en-US/docs/Web/API/WebGL_API/Tutorial/Using_textures_in_WebGL">here</a>. Please wait a sec for the texture to download.</li>
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<li>Then, I mapped the 3D sphere surface to the rectangular 2D texture picture. </li>
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<li>I also make it look like it's rotating by adding uTime to the offset of the texture and reset the offset to 0 whenever it exceeds
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the width of the texture.</li>
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<li>I used Perlin Noise to generate fake clouds.</li>
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<li> I modified the lighting so that the light source won't move with the sphere and
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the lighting will change when the sphere moves. I also added specular lights to make it shinier.</li>
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<li> Finally, I tried to add some 'soft shadow' to it. I used a mix of methods inspired by Ambient Occlusion and Ray Tracing.<br>
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<ul>
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<li>The Ambient lights and diffusion lights are reduced with respect to the distance between the background point and the sphere.</li>
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<li>The specular light of the background wall is eliminated and the diffusion factor is reduced when the ray shooting from the background point
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towards the light source or from the background point towards the camera position intersect with the sphere.</li>
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</ul>
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<li>Also, I made some small changes like changing R over time and refined the UI a little bit. I used
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<a href="https://ace.c9.io">Ace</a> for code highlighting and autocompletion on the edit panel.</li>
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<li>Comments begin with '//*' are added by me.</li>
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</li>
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</ul>
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<p>
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</script>
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<!!-------- YOU PROBABLY DON'T WANT TO CHANGE ANYTHING BELOW FOR NOW -------->
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<script>
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// CREATE THE HTML DOCUMENT
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let vs = my_vertex_shader.innerHTML,
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fs = my_fragment_shader.innerHTML;
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fs = fs.substring(1, fs.length);
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document.body.innerHTML = [''
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,'<margin-left:750px font size=8 color=#909090>' + my_title.innerHTML
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,'<TABLE cellspacing=0 cellpadding=0><TR>'
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,'<td><font color=red size=5><div id=errorMessage></div></font></td>'
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,'</TR><TR>'
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,'<table cellspacing=0>'
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,'<tr>'
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,'<td valign=top>'
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,'<div id="ace" style="width:800px;height:1650px;"></div>'
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,'</td><td valign=top>' + document.body.innerHTML + '<div style=\'font-size:25px\'>' + my_instructions.innerHTML + '</div>' + '</td>'
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,'</tr></table>'
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,'</TR></TABLE>'
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].join('');
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// SET UP THE EDITABLE TEXT AREA ON THE LEFT SIDE.
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let text = fs.split('\n'), cols = 0;
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for (let i = 0 ; i < text.length ; i++)
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cols = Math.max(cols, text[i].length);
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ace.require("ace/ext/language_tools");
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var editor = ace.edit("ace", {
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mode:"ace/mode/glsl",
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theme:"ace/theme/crimson_editor"
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});
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editor.setOptions({
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enableBasicAutocompletion: true,
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enableSnippets: true,
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enableLiveAutocompletion: true,
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fontSize: 14,
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fontFamily: "monaco, menlo, ubuntu mono, consolas, source-code-pro",
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fixedWidthGutter: true,
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showGutter: true,
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showPrintMargin: false,
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});
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editor.setAutoScrollEditorIntoView(true);
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editor.getSession().setValue(fs);
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// REPARSE THE SHADER PROGRAM AFTER EVERY KEYSTROKE.
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editor.session.on('change', function(delta) {
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canvas1.setShaders(vs, editor.getSession().getValue());
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});
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// SET THE CURRENT TIME IN SECONDS BEFORE RENDERING EACH FRAME.
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let startTime = Date.now();
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function animate(gl) {
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let time = (Date.now() - startTime) / 1000;
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setUniform('1f', 'uTime', time);
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}
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// START EVERYTHING.
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gl_start(canvas1, vs, fs);
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</script>
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