-
Notifications
You must be signed in to change notification settings - Fork 40
/
distancefield8.html
605 lines (523 loc) · 19.1 KB
/
distancefield8.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
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
<!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 sunDir;
uniform vec3 sunColour;
uniform vec3 diffuse;
uniform float ambient;
uniform bool ao;
uniform bool shadows;
uniform bool postEffects;
uniform bool moveCamera;
uniform bool fog;
uniform float fogC;
uniform float fogB;
uniform sampler2D texture0;
#define GAMMA 0.8
#define CONTRAST 1.2
#define SATURATION 1.4
#define BRIGHTNESS 1.4
#define RAY_DEPTH 256
#define MAX_DEPTH 256.0
#define SHADOW_RAY_DEPTH 48
#define AO_SAMPLES 4
#define FRACT_NOISE_DEPTH 7
#define DISTANCE_MIN 0.003
#define PI 3.14159265
const vec2 delta = vec2(DISTANCE_MIN, 0.);
const vec3 skyColour = vec3(0.75, 0.75, 0.65);
const vec3 rockColour = vec3(1.0, 0.8, 0.6);
float NoiseL(in vec2 x)
{
return texture2D(texture0,(x+vec2(0.5,0.5))/512.0,-100.0).x;
}
float Noise(in vec2 x)
{
vec2 p = floor(x);
vec2 f = fract(x);
f = f*f*(3.0-2.0*f);
float n = p.x + p.y*57.0;
float res = mix(mix( texture2D(texture0,(n+vec2(0.5,0.5))/512.0,-100.0).x, texture2D(texture0,(n+1.0+vec2(0.5,0.5))/512.0,-100.0).x,f.x),
mix( texture2D(texture0,(n+57.0+vec2(0.5,0.5))/512.0,-100.0).x, texture2D(texture0,(n+58.0+vec2(0.5,0.5))/512.0,-100.0).x,f.x),f.y);
return res;
}
float FractalNoise(in vec2 xy)
{
float w = 0.7;
float f = 0.0;
for (int i = 0; i < FRACT_NOISE_DEPTH - 2 - 2; i++)
{
f += Noise(xy) * w;
w *= 0.5;
xy *= 2.333;
}
return f;
}
float FractalNoiseM(in vec2 xy)
{
float w = 0.7;
float f = 0.0;
for (int i = 0; i < FRACT_NOISE_DEPTH - 2; i++)
{
f += Noise(xy) * w;
w *= 0.5;
xy *= 2.333;
}
return f;
}
float FractalNoiseH(in vec2 xy)
{
float w = 0.7;
float f = 0.0;
for (int i = 0; i < FRACT_NOISE_DEPTH; i++)
{
f += Noise(xy) * w;
w *= 0.5;
xy *= 2.333;
}
return f;
}
float Terrain(vec2 pos)
{
return Noise(pos.xy*0.899)*.5335 + FractalNoiseH(pos.yx*0.571)*0.693 - Noise(cos(pos.yx*0.673)+sin(pos.xy*0.615));
}
float TerrainM(vec2 pos)
{
return Noise(pos.xy*0.899)*.5335 + FractalNoiseM(pos.yx*0.571)*0.693 - Noise(cos(pos.yx*0.673)+sin(pos.xy*0.615));
}
// This should return continuous positive values when outside and negative values inside,
// which roughly indicate the distance of the nearest surface.
// NOTE! for increased performance, but lower Shadow/AO/intersect accuracy, change Terrain() to TerrainM() here
float Dist(vec3 pos)
{
return pos.y - TerrainM(pos.xz);
}
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);
}
vec3 CalcNormal(in vec3 pos, float t)
{
// NOTE: subtle changes to this value affect the sharpness of the normal - 0.001 is about same as GetNormal() above
vec2 eps = vec2(0.001*t, 0.0);
return normalize( vec3( Terrain(pos.xz-eps.xy) - Terrain(pos.xz+eps.xy),
2.0*eps.x,
Terrain(pos.xz-eps.yx) - Terrain(pos.xz+eps.yx) ) );
}
// Original method by David Hoskins
vec3 Clouds(in vec3 sky, in vec3 rd)
{
if (rd.y < 0.01) return sky;
float v = (200.0-cameraPos.y)/rd.y;
rd.xz *= v;
rd.xz += cameraPos.xz;
rd.xz *= .010;
float f = (FractalNoise(rd.xz) - 0.35) * 5.0;
// Uses the ray's y component for horizon fade of fixed colour clouds...
return mix(sky, skyColour, clamp(f*rd.y - 0.1, 0.0, 1.0));
}
// Original method by David Hoskins
vec3 Sky(in vec3 rd)
{
float sunAmount = max(dot(rd, sunDir), 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 += sunColour * sunAmount * sunAmount * .25 + sunColour * min(pow(sunAmount, 800.0)*1.5, .3);
return clamp(sky, 0.0, 1.0);
}
// Fog routine - original by IQ
vec3 Fog(vec3 rgb, vec3 rd, float distance) // camera to point distance
{
const float b = 0.015;
float fogAmount = 1.0 - exp(-distance*b);
vec3 fogColor = Sky(rd);
return mix(rgb, fogColor, fogAmount);
}
vec3 DepthFog(in vec3 rgb,in float distance, in vec3 rd, in vec3 ro)
{
float fogAmount = 0.0;
if (fog) fogAmount = fogC * exp(-ro.y*fogB) * (1.0-exp(-distance*rd.y*fogB))/rd.y;
return mix(rgb, Sky(rd), clamp(fogAmount, 0.0, 1.0));
}
// Based on original code by IQ
float SoftShadow(vec3 ro, vec3 rd)
{
float res = 1.0;
float k = 16.0;
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 < 16.0) // max-t
{
float h = Dist(ro + rd * t);
res = min(res, k*h/t);
t += h;
}
}
return clamp(res, 0.0, 1.0);
}
// Based on original code by IQ
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) * 0.2;
r += w * (d0 - Dist(p + n * d0));
w *= 0.5;
}
return 1.0 - clamp(r,0.0,1.0);
}
// "Natural light" shading - main sun light with soft shadows, sky light with AO and indirect sun bounce light with AO
// see http://iquilezles.org/www/articles/outdoorslighting/outdoorslighting.htm
vec3 Shading(vec3 pos, vec3 rd, vec3 norm, vec3 ro)
{
float sun = clamp(dot(norm, sunDir), 0.0, 1.0);
// start with rock colour, add in snow on peaks and grass in valleys
float snow = NoiseL(norm.yz*2.111);
float grass = NoiseL(norm.xy*0.973) - 0.2;
vec3 colour = rockColour;
// gives a more abrubt cut-off where snow is mixed into rock colour
if (pos.y > snow - 0.2) {
// apply norm.y so right angled surfaces receive less snow colour
colour = mix(colour, vec3(1.5), clamp(pos.y - snow + norm.y, 0.0, 1.0));
}
colour = mix(colour, vec3(0.1,0.7,0.2), 1.0 - clamp(pos.y + 0.25 + grass, 0.0, 1.0));
vec3 light = sun * sunColour * diffuse;
if (shadows) {
// colorize penumbras
light *= pow(vec3(SoftShadow(pos, sunDir)), vec3(1.0, 1.2, 1.5));
}
// sky light with AO
float occ = 0.0;
if (ao) {
occ = CalcAO(pos, norm) * ambient;
}
float sky = clamp(0.5 + 0.5 * norm.y, 0.0, 1.0);
light += sky * vec3(0.20, 0.20, 0.24) * occ;
// indirect light with AO
float ind = clamp(dot(norm, normalize(sunDir * vec3(-1.0,0.0,-1.0))), 0.0, 1.0);
light += ind * colour*0.2 * occ;
colour *= light;
// fogging
colour = DepthFog(colour, length(ro-pos), rd, ro);
//colour = Fog(colour, rd, length(ro-pos));
return colour;
}
// Original method by David Hoskins
vec3 PostEffects(vec3 rgb, vec2 xy)
{
rgb = pow(rgb, vec3(GAMMA));
rgb = mix(vec3(.5), mix(vec3(dot(vec3(.2125, .7154, .0721), rgb*BRIGHTNESS)), rgb*BRIGHTNESS, SATURATION), CONTRAST);
rgb *= .4+0.5*pow(40.0*xy.x*xy.y*(1.0-xy.x)*(1.0-xy.y), 0.2 );
return rgb;
}
// 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;
}
void main()
{
vec3 off = vec3(0.0);
if (moveCamera) {
off.z -= time*1.0;
off.y += cos(time*0.5)*0.5;
}
// position and ray direction
vec2 p = gl_FragCoord.xy / resolution.xy;
vec3 ro = cameraPos + off;
vec3 rd = normalize(GetRay((cameraLookat-off)-cameraPos+off, p));
// NOTE: for final AA - could move march function out again - as GetNormal() is fine for slow AA render pass
// march ray
// NOTE: see a number of tweaks here compared to my standard ray march loops:
// 1. using d<DISTANCE_MIN - i.e. removed the abs(d) to avoid holes in the fractal noise terrain
// 2. d * 0.75 to ensure small steps towards the terrain - avoids losing accuracy near terrain peaks (causing 'warping' of noise texture)
// 3. DISTANCE_MIN can be larger using the above changes, BUT higher RAY_DEPTH is needed to avoid missing distant features
// 4. still need MAX_DEPTH to avoid painful framerate
vec4 res = vec4(0.0);
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 (d < DISTANCE_MIN)
{
res = vec4(p, 1.0); // HIT
break;
}
t += d * 0.75;
if (t > MAX_DEPTH) break;
}
if (res.a == 0.0)
{
res.rgb = Clouds(Sky(rd), rd);
}
else
{
res.rgb = clamp(Shading(res.rgb, rd, CalcNormal(res.rgb, t), ro).rgb, 0.0, 1.0);
}
if (postEffects) res.rgb = PostEffects(res.rgb, p);
gl_FragColor = vec4(res.rgb, 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: 0.0, y: 2.0, z: 0.0
},
lookat: {
x: 25.0, y: -7.5, z: -65.0
},
sunDir: {
x: 1.0, y: 1.3, z: -4.0
},
sunColour: {
r: 1.4, g: 1.0, b: 0.6
},
surface: {
diffuse: 0.4,
ambient: 0.3
},
global: {
ao: true,
shadows: true,
postEffects: true,
moveCamera: true,
fog: true,
fogB: 0.1,
fogC: 0.2
}
};
var pause = false;
var stats = new Stats();
function init()
{
var img = new Image();
img.onload = function() {
loaded([img]);
};
img.src = "./noise512.png";
}
var _images;
var aspect, gl;
function loaded(images)
{
_images = images;
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(-256).max(256).step(0.1);
panel.add(config.camera, "y").min(-100).max(100).step(0.1);
panel.add(config.camera, "z").min(-100).max(100).step(0.1);
//panel.open();
panel = gui.addFolder('Camera LookAt');
panel.add(config.lookat, "x").min(-256).max(256).step(0.1);
panel.add(config.lookat, "y").min(-100).max(100).step(0.1);
panel.add(config.lookat, "z").min(-100).max(100).step(0.1);
if (!mobile) panel.open();
panel = gui.addFolder('Sun Direction');
panel.add(config.sunDir, "x").min(-10).max(10).step(0.1);
panel.add(config.sunDir, "y").min(-10).max(10).step(0.1);
panel.add(config.sunDir, "z").min(-10).max(10).step(0.1);
if (!mobile) panel.open();
panel = gui.addFolder('Sun Colour');
panel.add(config.sunColour, "r").min(0).max(3).step(0.1);
panel.add(config.sunColour, "g").min(0).max(3).step(0.1);
panel.add(config.sunColour, "b").min(0).max(3).step(0.1);
if (!mobile) panel.open();
panel = gui.addFolder('Surface');
panel.add(config.surface, "diffuse").min(0).max(1).step(0.05);
panel.add(config.surface, "ambient").min(0).max(1).step(0.05);
//panel.open();
panel = gui.addFolder('Global');
panel.add(config.global, "shadows").name("Shadows");
panel.add(config.global, "ao").name("Ambient Occlusion");
panel.add(config.global, "postEffects").name("Post Effects");
panel.add(config.global, "moveCamera").name("Move Camera");
panel.add(config.global, "fog").name("Fog");
panel.add(config.global, "fogB").min(0.01).max(1).step(0.01);
panel.add(config.global, "fogC").min(0.01).max(1).step(0.01);
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);
// textures
var noiseTexture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, noiseTexture);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, _images[0]);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR_MIPMAP_NEAREST);
gl.generateMipmap(gl.TEXTURE_2D);
gl.bindTexture(gl.TEXTURE_2D, null);
// 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.sunDir = gl.getUniformLocation(program, "sunDir");
// pre normalise light dir
var x = config.sunDir.x, y = config.sunDir.y, z = config.sunDir.z;
var len = x*x + y*y + z*z;
len = 1.0 / Math.sqrt(len);
gl.uniform3f(program.sunDir, config.sunDir.x*len, config.sunDir.y*len, config.sunDir.z*len);
program.sunColour = gl.getUniformLocation(program, "sunColour");
gl.uniform3f(program.sunColour, config.sunColour.r, config.sunColour.g, config.sunColour.b);
program.diffuse = gl.getUniformLocation(program, "diffuse");
gl.uniform3f(program.diffuse, config.surface.diffuse,config.surface.diffuse,config.surface.diffuse);
program.ambient = gl.getUniformLocation(program, "ambient");
gl.uniform1f(program.ambient, config.surface.ambient);
program.moveCamera = gl.getUniformLocation(program, "moveCamera");
gl.uniform1f(program.moveCamera, config.global.moveCamera);
program.postEffects = gl.getUniformLocation(program, "postEffects");
gl.uniform1f(program.postEffects, config.global.postEffects);
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.fog = gl.getUniformLocation(program, "fog");
gl.uniform1f(program.fog, config.global.fog);
program.fogB = gl.getUniformLocation(program, "fogB");
gl.uniform1f(program.fogB, config.global.fogB);
program.fogC = gl.getUniformLocation(program, "fogC");
gl.uniform1f(program.fogC, config.global.fogC);
gl.bindTexture(gl.TEXTURE_2D, noiseTexture);
gl.uniform1i(gl.getUniformLocation(program, "texture0"), 0);
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>