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
|
/*
* Copyright (C) 2007 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
function createVector(x,y,z) {
return new Array(x,y,z);
}
function sqrLengthVector(self) {
return self[0] * self[0] + self[1] * self[1] + self[2] * self[2];
}
function lengthVector(self) {
return Math.sqrt(self[0] * self[0] + self[1] * self[1] + self[2] * self[2]);
}
function addVector(self, v) {
self[0] += v[0];
self[1] += v[1];
self[2] += v[2];
return self;
}
function subVector(self, v) {
self[0] -= v[0];
self[1] -= v[1];
self[2] -= v[2];
return self;
}
function scaleVector(self, scale) {
self[0] *= scale;
self[1] *= scale;
self[2] *= scale;
return self;
}
function normaliseVector(self) {
var len = Math.sqrt(self[0] * self[0] + self[1] * self[1] + self[2] * self[2]);
self[0] /= len;
self[1] /= len;
self[2] /= len;
return self;
}
function add(v1, v2) {
return new Array(v1[0] + v2[0], v1[1] + v2[1], v1[2] + v2[2]);
}
function sub(v1, v2) {
return new Array(v1[0] - v2[0], v1[1] - v2[1], v1[2] - v2[2]);
}
function scalev(v1, v2) {
return new Array(v1[0] * v2[0], v1[1] * v2[1], v1[2] * v2[2]);
}
function dot(v1, v2) {
return v1[0] * v2[0] + v1[1] * v2[1] + v1[2] * v2[2];
}
function scale(v, scale) {
return [v[0] * scale, v[1] * scale, v[2] * scale];
}
function cross(v1, v2) {
return [v1[1] * v2[2] - v1[2] * v2[1],
v1[2] * v2[0] - v1[0] * v2[2],
v1[0] * v2[1] - v1[1] * v2[0]];
}
function normalise(v) {
var len = lengthVector(v);
return [v[0] / len, v[1] / len, v[2] / len];
}
function transformMatrix(self, v) {
var vals = self;
var x = vals[0] * v[0] + vals[1] * v[1] + vals[2] * v[2] + vals[3];
var y = vals[4] * v[0] + vals[5] * v[1] + vals[6] * v[2] + vals[7];
var z = vals[8] * v[0] + vals[9] * v[1] + vals[10] * v[2] + vals[11];
return [x, y, z];
}
function invertMatrix(self) {
var temp = new Array(16);
var tx = -self[3];
var ty = -self[7];
var tz = -self[11];
for (h = 0; h < 3; h++)
for (v = 0; v < 3; v++)
temp[h + v * 4] = self[v + h * 4];
for (i = 0; i < 11; i++)
self[i] = temp[i];
self[3] = tx * self[0] + ty * self[1] + tz * self[2];
self[7] = tx * self[4] + ty * self[5] + tz * self[6];
self[11] = tx * self[8] + ty * self[9] + tz * self[10];
return self;
}
// Triangle intersection using barycentric coord method
function Triangle(p1, p2, p3) {
var edge1 = sub(p3, p1);
var edge2 = sub(p2, p1);
var normal = cross(edge1, edge2);
if (Math.abs(normal[0]) > Math.abs(normal[1]))
if (Math.abs(normal[0]) > Math.abs(normal[2]))
this.axis = 0;
else
this.axis = 2;
else
if (Math.abs(normal[1]) > Math.abs(normal[2]))
this.axis = 1;
else
this.axis = 2;
var u = (this.axis + 1) % 3;
var v = (this.axis + 2) % 3;
var u1 = edge1[u];
var v1 = edge1[v];
var u2 = edge2[u];
var v2 = edge2[v];
this.normal = normalise(normal);
this.nu = normal[u] / normal[this.axis];
this.nv = normal[v] / normal[this.axis];
this.nd = dot(normal, p1) / normal[this.axis];
var det = u1 * v2 - v1 * u2;
this.eu = p1[u];
this.ev = p1[v];
this.nu1 = u1 / det;
this.nv1 = -v1 / det;
this.nu2 = v2 / det;
this.nv2 = -u2 / det;
this.material = [0.7, 0.7, 0.7];
}
Triangle.prototype.intersect = function(orig, dir, near, far) {
var u = (this.axis + 1) % 3;
var v = (this.axis + 2) % 3;
var d = dir[this.axis] + this.nu * dir[u] + this.nv * dir[v];
var t = (this.nd - orig[this.axis] - this.nu * orig[u] - this.nv * orig[v]) / d;
if (t < near || t > far)
return null;
var Pu = orig[u] + t * dir[u] - this.eu;
var Pv = orig[v] + t * dir[v] - this.ev;
var a2 = Pv * this.nu1 + Pu * this.nv1;
if (a2 < 0)
return null;
var a3 = Pu * this.nu2 + Pv * this.nv2;
if (a3 < 0)
return null;
if ((a2 + a3) > 1)
return null;
return t;
}
function Scene(a_triangles) {
this.triangles = a_triangles;
this.lights = [];
this.ambient = [0,0,0];
this.background = [0.8,0.8,1];
}
var zero = new Array(0,0,0);
Scene.prototype.intersect = function(origin, dir, near, far) {
var closest = null;
for (i = 0; i < this.triangles.length; i++) {
var triangle = this.triangles[i];
var d = triangle.intersect(origin, dir, near, far);
if (d == null || d > far || d < near)
continue;
far = d;
closest = triangle;
}
if (!closest)
return [this.background[0],this.background[1],this.background[2]];
var normal = closest.normal;
var hit = add(origin, scale(dir, far));
if (dot(dir, normal) > 0)
normal = [-normal[0], -normal[1], -normal[2]];
var colour = null;
if (closest.shader) {
colour = closest.shader(closest, hit, dir);
} else {
colour = closest.material;
}
// do reflection
var reflected = null;
if (colour.reflection > 0.001) {
var reflection = addVector(scale(normal, -2*dot(dir, normal)), dir);
reflected = this.intersect(hit, reflection, 0.0001, 1000000);
if (colour.reflection >= 0.999999)
return reflected;
}
var l = [this.ambient[0], this.ambient[1], this.ambient[2]];
for (var i = 0; i < this.lights.length; i++) {
var light = this.lights[i];
var toLight = sub(light, hit);
var distance = lengthVector(toLight);
scaleVector(toLight, 1.0/distance);
distance -= 0.0001;
if (this.blocked(hit, toLight, distance))
continue;
var nl = dot(normal, toLight);
if (nl > 0)
addVector(l, scale(light.colour, nl));
}
l = scalev(l, colour);
if (reflected) {
l = addVector(scaleVector(l, 1 - colour.reflection), scaleVector(reflected, colour.reflection));
}
return l;
}
Scene.prototype.blocked = function(O, D, far) {
var near = 0.0001;
var closest = null;
for (i = 0; i < this.triangles.length; i++) {
var triangle = this.triangles[i];
var d = triangle.intersect(O, D, near, far);
if (d == null || d > far || d < near)
continue;
return true;
}
return false;
}
// this camera code is from notes i made ages ago, it is from *somewhere* -- i cannot remember where
// that somewhere is
function Camera(origin, lookat, up) {
var zaxis = normaliseVector(subVector(lookat, origin));
var xaxis = normaliseVector(cross(up, zaxis));
var yaxis = normaliseVector(cross(xaxis, subVector([0,0,0], zaxis)));
var m = new Array(16);
m[0] = xaxis[0]; m[1] = xaxis[1]; m[2] = xaxis[2];
m[4] = yaxis[0]; m[5] = yaxis[1]; m[6] = yaxis[2];
m[8] = zaxis[0]; m[9] = zaxis[1]; m[10] = zaxis[2];
invertMatrix(m);
m[3] = 0; m[7] = 0; m[11] = 0;
this.origin = origin;
this.directions = new Array(4);
this.directions[0] = normalise([-0.7, 0.7, 1]);
this.directions[1] = normalise([ 0.7, 0.7, 1]);
this.directions[2] = normalise([ 0.7, -0.7, 1]);
this.directions[3] = normalise([-0.7, -0.7, 1]);
this.directions[0] = transformMatrix(m, this.directions[0]);
this.directions[1] = transformMatrix(m, this.directions[1]);
this.directions[2] = transformMatrix(m, this.directions[2]);
this.directions[3] = transformMatrix(m, this.directions[3]);
}
Camera.prototype.generateRayPair = function(y) {
rays = new Array(new Object(), new Object());
rays[0].origin = this.origin;
rays[1].origin = this.origin;
rays[0].dir = addVector(scale(this.directions[0], y), scale(this.directions[3], 1 - y));
rays[1].dir = addVector(scale(this.directions[1], y), scale(this.directions[2], 1 - y));
return rays;
}
function renderRows(camera, scene, pixels, width, height, starty, stopy) {
for (var y = starty; y < stopy; y++) {
var rays = camera.generateRayPair(y / height);
for (var x = 0; x < width; x++) {
var xp = x / width;
var origin = addVector(scale(rays[0].origin, xp), scale(rays[1].origin, 1 - xp));
var dir = normaliseVector(addVector(scale(rays[0].dir, xp), scale(rays[1].dir, 1 - xp)));
var l = scene.intersect(origin, dir);
pixels[y][x] = l;
}
}
}
Camera.prototype.render = function(scene, pixels, width, height) {
var cam = this;
var row = 0;
renderRows(cam, scene, pixels, width, height, 0, height);
}
function raytraceScene()
{
var startDate = new Date().getTime();
var numTriangles = 2 * 6;
var triangles = new Array();//numTriangles);
var tfl = createVector(-10, 10, -10);
var tfr = createVector( 10, 10, -10);
var tbl = createVector(-10, 10, 10);
var tbr = createVector( 10, 10, 10);
var bfl = createVector(-10, -10, -10);
var bfr = createVector( 10, -10, -10);
var bbl = createVector(-10, -10, 10);
var bbr = createVector( 10, -10, 10);
// cube!!!
// front
var i = 0;
triangles[i++] = new Triangle(tfl, tfr, bfr);
triangles[i++] = new Triangle(tfl, bfr, bfl);
// back
triangles[i++] = new Triangle(tbl, tbr, bbr);
triangles[i++] = new Triangle(tbl, bbr, bbl);
// triangles[i-1].material = [0.7,0.2,0.2];
// triangles[i-1].material.reflection = 0.8;
// left
triangles[i++] = new Triangle(tbl, tfl, bbl);
// triangles[i-1].reflection = 0.6;
triangles[i++] = new Triangle(tfl, bfl, bbl);
// triangles[i-1].reflection = 0.6;
// right
triangles[i++] = new Triangle(tbr, tfr, bbr);
triangles[i++] = new Triangle(tfr, bfr, bbr);
// top
triangles[i++] = new Triangle(tbl, tbr, tfr);
triangles[i++] = new Triangle(tbl, tfr, tfl);
// bottom
triangles[i++] = new Triangle(bbl, bbr, bfr);
triangles[i++] = new Triangle(bbl, bfr, bfl);
//Floor!!!!
var green = createVector(0.0, 0.4, 0.0);
var grey = createVector(0.4, 0.4, 0.4);
grey.reflection = 1.0;
var floorShader = function(tri, pos, view) {
var x = ((pos[0]/32) % 2 + 2) % 2;
var z = ((pos[2]/32 + 0.3) % 2 + 2) % 2;
if (x < 1 != z < 1) {
//in the real world we use the fresnel term...
// var angle = 1-dot(view, tri.normal);
// angle *= angle;
// angle *= angle;
// angle *= angle;
//grey.reflection = angle;
return grey;
} else
return green;
}
var ffl = createVector(-1000, -30, -1000);
var ffr = createVector( 1000, -30, -1000);
var fbl = createVector(-1000, -30, 1000);
var fbr = createVector( 1000, -30, 1000);
triangles[i++] = new Triangle(fbl, fbr, ffr);
triangles[i-1].shader = floorShader;
triangles[i++] = new Triangle(fbl, ffr, ffl);
triangles[i-1].shader = floorShader;
var _scene = new Scene(triangles);
_scene.lights[0] = createVector(20, 38, -22);
_scene.lights[0].colour = createVector(0.7, 0.3, 0.3);
_scene.lights[1] = createVector(-23, 40, 17);
_scene.lights[1].colour = createVector(0.7, 0.3, 0.3);
_scene.lights[2] = createVector(23, 20, 17);
_scene.lights[2].colour = createVector(0.7, 0.7, 0.7);
_scene.ambient = createVector(0.1, 0.1, 0.1);
// _scene.background = createVector(0.7, 0.7, 1.0);
var size = 30;
var pixels = new Array();
for (var y = 0; y < size; y++) {
pixels[y] = new Array();
for (var x = 0; x < size; x++) {
pixels[y][x] = 0;
}
}
var _camera = new Camera(createVector(-40, 40, 40), createVector(0, 0, 0), createVector(0, 1, 0));
_camera.render(_scene, pixels, size, size);
return pixels;
}
function arrayToCanvasCommands(pixels)
{
var s = '<canvas id="renderCanvas" width="30px" height="30px"></canvas><scr' + 'ipt>\nvar pixels = [';
var size = 30;
for (var y = 0; y < size; y++) {
s += "[";
for (var x = 0; x < size; x++) {
s += "[" + pixels[y][x] + "],";
}
s+= "],";
}
s += '];\n var canvas = document.getElementById("renderCanvas").getContext("2d");\n\
\n\
\n\
var size = 30;\n\
canvas.fillStyle = "red";\n\
canvas.fillRect(0, 0, size, size);\n\
canvas.scale(1, -1);\n\
canvas.translate(0, -size);\n\
\n\
if (!canvas.setFillColor)\n\
canvas.setFillColor = function(r, g, b, a) {\n\
this.fillStyle = "rgb("+[Math.floor(r * 255), Math.floor(g * 255), Math.floor(b * 255)]+")";\n\
}\n\
\n\
for (var y = 0; y < size; y++) {\n\
for (var x = 0; x < size; x++) {\n\
var l = pixels[y][x];\n\
canvas.setFillColor(l[0], l[1], l[2], 1);\n\
canvas.fillRect(x, y, 1, 1);\n\
}\n\
}</scr' + 'ipt>';
return s;
}
testOutput = arrayToCanvasCommands(raytraceScene());
|