-
Notifications
You must be signed in to change notification settings - Fork 40
/
mengersponge.html
467 lines (403 loc) · 14.5 KB
/
mengersponge.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
<!DOCTYPE html>
<html>
<head>
<!--
Ray Marching demo by Kevin Roast
- Lots of code/ideas for this demo come from reading:
http://www.iquilezles.org/www/material/nvscene2008/rwwtt.pdf
http://www.pouet.net/topic.php?which=7931&page=1
http://www.pouet.net/topic.php?which=7920&page=1
http://iquilezles.org/www/articles/distfunctions/distfunctions.htm
https://www.shadertoy.com/
If you want to understand this stuff read through the PDF and pouet.net links above!
-->
<script src="scripts/dat.gui.min.js"></script>
<script src="scripts/stats.min.js"></script>
<script id="vertex" type="x-shader">
attribute vec2 aVertexPosition;
void main()
{
gl_Position = vec4(aVertexPosition, 0.0, 1.0);
}
</script>
<script id="fragment" type="x-shader">
#ifdef GL_ES
precision highp float;
#endif
uniform float time;
uniform vec2 resolution;
uniform vec3 cameraPos;
uniform vec3 cameraLookat;
uniform vec3 lightDir;
uniform vec3 lightColour;
uniform float specular;
uniform float specularHardness;
uniform vec3 diffuse;
uniform float ambientFactor;
uniform bool ao;
uniform bool shadows;
uniform bool rotateWorld;
uniform bool antialias;
#define GAMMA 0.8
#define AO_SAMPLES 5
#define RAY_DEPTH 256
#define MAX_DEPTH 200.0
#define SHADOW_RAY_DEPTH 48
#define DISTANCE_MIN 0.002
#define PI 3.14159265
const vec2 delta = vec2(0.001, 0.);
vec3 RotateY(vec3 p, float a)
{
float c,s;
vec3 q=p;
c = cos(a);
s = sin(a);
p.x = c * q.x + s * q.z;
p.z = -s * q.x + c * q.z;
return p;
}
float Cross(vec3 p)
{
p = abs(p);
vec3 d = vec3(max(p.x, p.y),
max(p.y, p.z),
max(p.z, p.x));
return min(d.x, min(d.y, d.z)) - (1.0 / 3.0);
}
float CrossRep(vec3 p)
{
vec3 q = mod(p + 1.0, 2.0) - 1.0;
return Cross(q);
}
float CrossRepScale(vec3 p, float s)
{
return CrossRep(p * s) / s;
}
const int MENGER_ITERATIONS = 4;
float Dist(vec3 pos)
{
if (rotateWorld) pos = RotateY(pos, sin(time*0.025)*PI);
float scale = 0.05;
float dist = 0.0;
for (int i = 0; i < MENGER_ITERATIONS; i++)
{
dist = max(dist, -CrossRepScale(pos, scale));
scale *= 3.0;
}
return dist;
}
// Based on original by IQ - optimized to remove a divide
float CalcAO(vec3 p, vec3 n)
{
float r = 0.0;
float w = 1.0;
for (int i=1; i<=AO_SAMPLES; i++)
{
float d0 = float(i) * 0.3;
r += w * (d0 - Dist(p + n * d0));
w *= 0.5;
}
return 1.0 - clamp(r,0.0,1.0);
}
// Based on original code by IQ
float SoftShadow(vec3 ro, vec3 rd, float k)
{
float res = 1.0;
float t = 0.1; // min-t see http://www.iquilezles.org/www/articles/rmshadows/rmshadows.htm
for (int i=0; i<SHADOW_RAY_DEPTH; i++)
{
if (t < 20.0) // max-t
{
float h = Dist(ro + rd * t);
res = min(res, k*h/t);
t += h;
}
}
return clamp(res, 0.0, 1.0);
}
vec3 GetNormal(vec3 pos)
{
vec3 n;
n.x = Dist( pos + delta.xyy ) - Dist( pos - delta.xyy );
n.y = Dist( pos + delta.yxy ) - Dist( pos - delta.yxy );
n.z = Dist( pos + delta.yyx ) - Dist( pos - delta.yyx );
return normalize(n);
}
// Based on a shading method by Ben Weston. Added AO and SoftShadows to original.
vec4 Shading(vec3 pos, vec3 rd, vec3 norm)
{
vec3 light = lightColour * max(0.0, dot(norm, lightDir));
vec3 heading = normalize(-rd + lightDir);
float spec = pow(max(0.0, dot(heading, norm)), specularHardness);
light = (diffuse * light) + (spec * specular * lightColour);
if (shadows) light *= SoftShadow(pos, lightDir, 16.0);
if (ao) light += CalcAO(pos, norm) * ambientFactor;
return vec4(light, 1.0);
}
// Original method by David Hoskins
vec3 Sky(in vec3 rd)
{
float sunAmount = max(dot(rd, lightDir), 0.0);
float v = pow(1.0 - max(rd.y,0.0),6.);
vec3 sky = mix(vec3(.1, .2, .3), vec3(.32, .32, .32), v);
sky += lightColour * sunAmount * sunAmount * .25 + lightColour * min(pow(sunAmount, 800.0)*1.5, .3);
return clamp(sky, 0.0, 1.0);
}
// Camera function by TekF
// Compute ray from camera parameters
vec3 GetRay(vec3 dir, vec2 pos)
{
pos = pos - 0.5;
pos.x *= resolution.x/resolution.y;
dir = normalize(dir);
vec3 right = normalize(cross(vec3(0.,1.,0.),dir));
vec3 up = normalize(cross(dir,right));
return dir + right*pos.x + up*pos.y;
}
vec4 March(vec3 ro, vec3 rd)
{
float t = 0.0;
float d = 1.0;
for (int i=0; i<RAY_DEPTH; i++)
{
vec3 p = ro + rd * t;
d = Dist(p);
if (abs(d) < DISTANCE_MIN)
{
return vec4(p, 1.0);
}
t += d;
if (t >= MAX_DEPTH) break;
}
return vec4(0.0);
}
void main()
{
const int ANTIALIAS_SAMPLES = 4;
vec4 res = vec4(0.0);
if (antialias)
{
float d_ang = 2.*PI / float(ANTIALIAS_SAMPLES);
float ang = d_ang * 0.33333;
float r = .3;
for (int i = 0; i < ANTIALIAS_SAMPLES; i++)
{
vec2 p = vec2((gl_FragCoord.x + cos(ang)*r) / resolution.x, (gl_FragCoord.y + sin(ang)*r) / resolution.y);
vec3 ro = cameraPos;
vec3 rd = normalize(GetRay(cameraLookat-cameraPos, p));
vec4 _res = March(ro, rd);
if (_res.a == 1.0) res.xyz += clamp(Shading(_res.xyz, rd, GetNormal(_res.xyz)).xyz, 0.0, 1.0);
else res.xyz += Sky(_res.xyz);
ang += d_ang;
}
res /= float(ANTIALIAS_SAMPLES);
}
else
{
vec2 p = gl_FragCoord.xy / resolution.xy;
vec3 ro = cameraPos;
vec3 rd = normalize(GetRay(cameraLookat-cameraPos, p));
res = March(ro, rd);
if (res.a == 1.0) res.xyz = clamp(Shading(res.xyz, rd, GetNormal(res.xyz)).xyz, 0.0, 1.0);
else res.xyz = Sky(res.xyz);
}
gl_FragColor = vec4(res.xyz, 1.0);
}
</script>
<script type="text/javascript">
var requestAnimationFrame = window.requestAnimationFrame || window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame || window.msRequestAnimationFrame ||
function(c) {window.setTimeout(c, 15)};
var config = {
camera: {
x: 1.0, y: 1.0, z: -5.0
},
lookat: {
x: 0.0, y: 0.0, z: 0.0
},
lightDir: {
x: -2.0, y: 0.8, z: -1.0
},
lightColour: {
r: 2.0, g: 1.8, b: 1.5
},
surface: {
specular: 64.0,
specularHardness: 512.0,
diffuse: 0.25,
ambientFactor: 0.65
},
global: {
ao: true,
shadows: false,
rotateWorld: true,
antialias: false
}
};
var pause = false;
var stats = new Stats();
var aspect, gl;
function init()
{
document.addEventListener('keydown', function(e) {
switch (e.keyCode)
{
case 27: // ESC
pause = !pause;
break;
}
}, false);
// add GUI controls
var mobile = (navigator.userAgent.indexOf("Android") !== -1);
var gui = new dat.GUI();
var panel = gui.addFolder('Camera Position');
panel.add(config.camera, "x").min(-16.0).max(16.0).step(0.1);
panel.add(config.camera, "y").min(-16.0).max(16.0).step(0.1);
panel.add(config.camera, "z").min(-64.0).max(64.0).step(0.1);
panel.open();
panel = gui.addFolder('Camera LookAt');
panel.add(config.lookat, "x").min(-16.0).max(16.0).step(0.1);
panel.add(config.lookat, "y").min(-16.0).max(16.0).step(0.1);
panel.add(config.lookat, "z").min(-16.0).max(16.0).step(0.1);
if (!mobile) panel.open();
panel = gui.addFolder('Light Direction');
panel.add(config.lightDir, "x").min(-16.0).max(16.0).step(0.1);
panel.add(config.lightDir, "y").min(-16.0).max(16.0).step(0.1);
panel.add(config.lightDir, "z").min(-16.0).max(16.0).step(0.1);
//if (!mobile) panel.open();
panel = gui.addFolder('Light Colour');
panel.add(config.lightColour, "r").min(0.0).max(3.0).step(0.1);
panel.add(config.lightColour, "g").min(0.0).max(3.0).step(0.1);
panel.add(config.lightColour, "b").min(0.0).max(3.0).step(0.1);
//if (!mobile) panel.open();
panel = gui.addFolder('Surface');
panel.add(config.surface, "specular").min(0).max(64);
panel.add(config.surface, "specularHardness").min(16).max(1024).step(16);
panel.add(config.surface, "diffuse").min(0).max(1).step(0.05);
panel.add(config.surface, "ambientFactor").min(0).max(1).step(0.05);
//panel.open();
panel = gui.addFolder('Global');
panel.add(config.global, "antialias").name("Anti Alias");
panel.add(config.global, "shadows").name("Shadows");
panel.add(config.global, "ao").name("Ambient Occlusion");
panel.add(config.global, "rotateWorld").name("Rotate World");
if (!mobile) panel.open();
document.body.appendChild(stats.domElement);
// create webgl context on the canvas element
var canvas = document.getElementById("canvas");
aspect = canvas.width / canvas.height;
try
{
gl = canvas.getContext("experimental-webgl");
}
catch (e)
{
document.write("Whoops! No useful WEB-GL impl available. Shame on you and your browser vendor.<br>" + e.message);
return;
}
gl.viewport(0, 0, canvas.width, canvas.height);
gl.clearColor(0, 0, 0, 1);
gl.clear(gl.COLOR_BUFFER_BIT);
// get the vertex and fragment shader source
var v = document.getElementById("vertex").firstChild.nodeValue;
var f = document.getElementById("fragment").firstChild.nodeValue;
// compile and link the shaders
var vs = gl.createShader(gl.VERTEX_SHADER);
gl.shaderSource(vs, v);
gl.compileShader(vs);
var fs = gl.createShader(gl.FRAGMENT_SHADER);
gl.shaderSource(fs, f);
gl.compileShader(fs);
var program = gl.createProgram();
gl.attachShader(program, vs);
gl.attachShader(program, fs);
gl.linkProgram(program);
// debug shader compile status
var error = false;
if (!gl.getShaderParameter(vs, gl.COMPILE_STATUS))
{
error = true;
console.log(gl.getShaderInfoLog(vs));
}
if (!gl.getShaderParameter(fs, gl.COMPILE_STATUS))
{
error = true;
console.log(gl.getShaderInfoLog(fs));
}
if (!gl.getProgramParameter(program, gl.LINK_STATUS))
{
error = true;
console.log(gl.getProgramInfoLog(program));
}
if (error) return;
var firstTime = Date.now();
(f = function() {
if (!pause)
{
stats.begin();
// create vertices to fill the canvas with a single quad
var vertices = new Float32Array(
[
-1, 1*aspect, 1, 1*aspect, 1, -1*aspect,
-1, 1*aspect, 1, -1*aspect, -1, -1*aspect
]);
var vbuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, vbuffer);
gl.bufferData(gl.ARRAY_BUFFER, vertices, gl.STATIC_DRAW);
var triCount = 2,
numItems = vertices.length / triCount;
gl.useProgram(program);
var time = (Date.now() - firstTime) / 1000.0;
program.time = gl.getUniformLocation(program, "time");
gl.uniform1f(program.time, time);
program.resolution = gl.getUniformLocation(program, "resolution");
gl.uniform2f(program.resolution, canvas.width, canvas.height);
program.cameraPos = gl.getUniformLocation(program, "cameraPos");
gl.uniform3f(program.cameraPos, config.camera.x, config.camera.y, config.camera.z);
program.cameraLookat = gl.getUniformLocation(program, "cameraLookat");
gl.uniform3f(program.cameraLookat, config.lookat.x, config.lookat.y, config.lookat.z);
program.lightDir = gl.getUniformLocation(program, "lightDir");
// pre normalise light dir
var x = config.lightDir.x, y = config.lightDir.y, z = config.lightDir.z;
var len = x*x + y*y + z*z;
len = 1.0 / Math.sqrt(len);
gl.uniform3f(program.lightDir, config.lightDir.x*len, config.lightDir.y*len, config.lightDir.z*len);
program.lightColour = gl.getUniformLocation(program, "lightColour");
gl.uniform3f(program.lightColour, config.lightColour.r, config.lightColour.g, config.lightColour.b);
program.specular = gl.getUniformLocation(program, "specular");
gl.uniform1f(program.specular, config.surface.specular);
program.specularHardness = gl.getUniformLocation(program, "specularHardness");
gl.uniform1f(program.specularHardness, config.surface.specularHardness);
program.diffuse = gl.getUniformLocation(program, "diffuse");
gl.uniform3f(program.diffuse, config.surface.diffuse,config.surface.diffuse,config.surface.diffuse);
program.ambientFactor = gl.getUniformLocation(program, "ambientFactor");
gl.uniform1f(program.ambientFactor, config.surface.ambientFactor);
program.rotateWorld = gl.getUniformLocation(program, "rotateWorld");
gl.uniform1f(program.rotateWorld, config.global.rotateWorld);
program.ao = gl.getUniformLocation(program, "ao");
gl.uniform1f(program.ao, config.global.ao);
program.shadows = gl.getUniformLocation(program, "shadows");
gl.uniform1f(program.shadows, config.global.shadows);
program.antialias = gl.getUniformLocation(program, "antialias");
gl.uniform1f(program.antialias, config.global.antialias);
program.aVertexPosition = gl.getAttribLocation(program, "aVertexPosition");
gl.enableVertexAttribArray(program.aVertexPosition);
gl.vertexAttribPointer(program.aVertexPosition, triCount, gl.FLOAT, false, 0, 0);
gl.drawArrays(gl.TRIANGLES, 0, numItems);
stats.end();
}
requestAnimationFrame(f);
})();
}
</script>
<script src="scripts/utils.js"></script>
<link rel="stylesheet" href="../../reset.css">
<link rel="stylesheet" href="./page.css">
<link href='http://fonts.googleapis.com/css?family=Open+Sans:400,300,600' rel='stylesheet' type='text/css'>
</head>
<body onload="init()">
<canvas id="canvas" width="768" height="512"></canvas>
<a href="#" id="fullscreen">Toggle Full Screen</a>
<a href="." id="back">Show me more awesome demos!</a>
</body>
</html>