| 1 |
/* Copyright (c) 1986 Regents of the University of California */ |
| 2 |
|
| 3 |
#ifndef lint |
| 4 |
static char SCCSid[] = "$SunId$ LBL"; |
| 5 |
#endif |
| 6 |
|
| 7 |
/* |
| 8 |
* ambient.c - routines dealing with ambient (inter-reflected) component. |
| 9 |
* |
| 10 |
* The macro AMBFLUSH (if defined) is the number of ambient values |
| 11 |
* to wait before flushing to the ambient file. |
| 12 |
* |
| 13 |
* 5/9/86 |
| 14 |
*/ |
| 15 |
|
| 16 |
#include "ray.h" |
| 17 |
|
| 18 |
#include "octree.h" |
| 19 |
|
| 20 |
#include "otypes.h" |
| 21 |
|
| 22 |
#include "random.h" |
| 23 |
|
| 24 |
#define OCTSCALE 0.5 /* ceil((valid rad.)/(cube size)) */ |
| 25 |
|
| 26 |
extern CUBE thescene; /* contains space boundaries */ |
| 27 |
|
| 28 |
extern COLOR ambval; /* global ambient component */ |
| 29 |
extern double ambacc; /* ambient accuracy */ |
| 30 |
extern int ambres; /* ambient resolution */ |
| 31 |
extern int ambdiv; /* number of divisions for calculation */ |
| 32 |
extern int ambssamp; /* number of super-samples */ |
| 33 |
extern int ambounce; /* number of ambient bounces */ |
| 34 |
extern char *amblist[]; /* ambient include/exclude list */ |
| 35 |
extern int ambincl; /* include == 1, exclude == 0 */ |
| 36 |
|
| 37 |
#define MAXASET 511 /* maximum number of elements in ambient set */ |
| 38 |
OBJECT ambset[MAXASET+1]={0}; /* ambient include/exclude set */ |
| 39 |
|
| 40 |
double maxarad; /* maximum ambient radius */ |
| 41 |
double minarad; /* minimum ambient radius */ |
| 42 |
|
| 43 |
/* |
| 44 |
* Since we've defined our vectors as float below to save space, |
| 45 |
* watch out for changes in the definitions of VCOPY() and DOT(). |
| 46 |
*/ |
| 47 |
typedef struct ambval { |
| 48 |
float pos[3]; /* position in space */ |
| 49 |
float dir[3]; /* normal direction */ |
| 50 |
int lvl; /* recursion level of parent ray */ |
| 51 |
float weight; /* weight of parent ray */ |
| 52 |
COLOR val; /* computed ambient value */ |
| 53 |
float rad; /* validity radius */ |
| 54 |
struct ambval *next; /* next in list */ |
| 55 |
} AMBVAL; /* ambient value */ |
| 56 |
|
| 57 |
typedef struct ambtree { |
| 58 |
AMBVAL *alist; /* ambient value list */ |
| 59 |
struct ambtree *kid; /* 8 child nodes */ |
| 60 |
} AMBTREE; /* ambient octree */ |
| 61 |
|
| 62 |
typedef struct { |
| 63 |
float k; /* error contribution per sample */ |
| 64 |
COLOR v; /* ray sum */ |
| 65 |
int n; /* number of samples */ |
| 66 |
short t, p; /* theta, phi indices */ |
| 67 |
} AMBSAMP; /* ambient sample */ |
| 68 |
|
| 69 |
static AMBTREE atrunk; /* our ambient trunk node */ |
| 70 |
|
| 71 |
static FILE *ambfp = NULL; /* ambient file pointer */ |
| 72 |
|
| 73 |
#define newambval() (AMBVAL *)bmalloc(sizeof(AMBVAL)) |
| 74 |
|
| 75 |
#define newambtree() (AMBTREE *)calloc(8, sizeof(AMBTREE)) |
| 76 |
|
| 77 |
double sumambient(), doambient(), makeambient(); |
| 78 |
|
| 79 |
|
| 80 |
setambient(afile) /* initialize calculation */ |
| 81 |
char *afile; |
| 82 |
{ |
| 83 |
long ftell(); |
| 84 |
AMBVAL amb; |
| 85 |
|
| 86 |
maxarad = thescene.cusize / 2.0; /* maximum radius */ |
| 87 |
/* minimum radius */ |
| 88 |
minarad = ambres > 0 ? thescene.cusize/ambres : 0.0; |
| 89 |
|
| 90 |
/* open ambient file */ |
| 91 |
if (afile != NULL) |
| 92 |
if ((ambfp = fopen(afile, "r+")) != NULL) { |
| 93 |
while (fread((char *)&amb,sizeof(AMBVAL),1,ambfp) == 1) |
| 94 |
avinsert(&amb, &atrunk, thescene.cuorg, |
| 95 |
thescene.cusize); |
| 96 |
/* align */ |
| 97 |
fseek(ambfp, -(ftell(ambfp)%sizeof(AMBVAL)), 1); |
| 98 |
} else if ((ambfp = fopen(afile, "w")) == NULL) { |
| 99 |
sprintf(errmsg, "cannot open ambient file \"%s\"", |
| 100 |
afile); |
| 101 |
error(SYSTEM, errmsg); |
| 102 |
} |
| 103 |
} |
| 104 |
|
| 105 |
|
| 106 |
ambnotify(obj) /* record new modifier */ |
| 107 |
OBJECT obj; |
| 108 |
{ |
| 109 |
static int hitlimit = 0; |
| 110 |
register OBJREC *o = objptr(obj); |
| 111 |
register char **amblp; |
| 112 |
|
| 113 |
if (hitlimit || !ismodifier(o->otype)) |
| 114 |
return; |
| 115 |
for (amblp = amblist; *amblp != NULL; amblp++) |
| 116 |
if (!strcmp(o->oname, *amblp)) { |
| 117 |
if (ambset[0] >= MAXASET) { |
| 118 |
error(WARNING, "too many modifiers in ambient list"); |
| 119 |
hitlimit++; |
| 120 |
return; /* should this be fatal? */ |
| 121 |
} |
| 122 |
insertelem(ambset, obj); |
| 123 |
return; |
| 124 |
} |
| 125 |
} |
| 126 |
|
| 127 |
|
| 128 |
ambient(acol, r) /* compute ambient component for ray */ |
| 129 |
COLOR acol; |
| 130 |
register RAY *r; |
| 131 |
{ |
| 132 |
static int rdepth = 0; /* ambient recursion */ |
| 133 |
double wsum; |
| 134 |
|
| 135 |
rdepth++; /* increment level */ |
| 136 |
|
| 137 |
if (ambdiv <= 0) /* no ambient calculation */ |
| 138 |
goto dumbamb; |
| 139 |
/* check number of bounces */ |
| 140 |
if (rdepth > ambounce) |
| 141 |
goto dumbamb; |
| 142 |
/* check ambient list */ |
| 143 |
if (ambincl != -1 && r->ro != NULL && |
| 144 |
ambincl != inset(ambset, r->ro->omod)) |
| 145 |
goto dumbamb; |
| 146 |
|
| 147 |
if (ambacc <= FTINY) { /* no ambient storage */ |
| 148 |
if (doambient(acol, r) == 0.0) |
| 149 |
goto dumbamb; |
| 150 |
goto done; |
| 151 |
} |
| 152 |
/* get ambient value */ |
| 153 |
setcolor(acol, 0.0, 0.0, 0.0); |
| 154 |
wsum = sumambient(acol, r, &atrunk, thescene.cuorg, thescene.cusize); |
| 155 |
if (wsum > FTINY) |
| 156 |
scalecolor(acol, 1.0/wsum); |
| 157 |
else if (makeambient(acol, r) == 0.0) |
| 158 |
goto dumbamb; |
| 159 |
goto done; |
| 160 |
|
| 161 |
dumbamb: /* return global value */ |
| 162 |
copycolor(acol, ambval); |
| 163 |
done: /* must finish here! */ |
| 164 |
rdepth--; |
| 165 |
} |
| 166 |
|
| 167 |
|
| 168 |
double |
| 169 |
sumambient(acol, r, at, c0, s) /* get interpolated ambient value */ |
| 170 |
COLOR acol; |
| 171 |
register RAY *r; |
| 172 |
AMBTREE *at; |
| 173 |
FVECT c0; |
| 174 |
double s; |
| 175 |
{ |
| 176 |
extern double sqrt(); |
| 177 |
double d, e1, e2, wt, wsum; |
| 178 |
COLOR ct; |
| 179 |
FVECT ck0; |
| 180 |
int i; |
| 181 |
register int j; |
| 182 |
register AMBVAL *av; |
| 183 |
/* do this node */ |
| 184 |
wsum = 0.0; |
| 185 |
for (av = at->alist; av != NULL; av = av->next) { |
| 186 |
/* |
| 187 |
* Ray strength test. |
| 188 |
*/ |
| 189 |
if (av->lvl > r->rlvl || av->weight < r->rweight-FTINY) |
| 190 |
continue; |
| 191 |
/* |
| 192 |
* Ambient radius test. |
| 193 |
*/ |
| 194 |
e1 = 0.0; |
| 195 |
for (j = 0; j < 3; j++) { |
| 196 |
d = av->pos[j] - r->rop[j]; |
| 197 |
e1 += d * d; |
| 198 |
} |
| 199 |
e1 /= av->rad * av->rad; |
| 200 |
if (e1 > ambacc*ambacc*1.21) |
| 201 |
continue; |
| 202 |
/* |
| 203 |
* Normal direction test. |
| 204 |
*/ |
| 205 |
e2 = (1.0 - DOT(av->dir, r->ron)) * r->rweight; |
| 206 |
if (e2 < 0.0) e2 = 0.0; |
| 207 |
if (e1 + e2 > ambacc*ambacc*1.21) |
| 208 |
continue; |
| 209 |
/* |
| 210 |
* Ray behind test. |
| 211 |
*/ |
| 212 |
d = 0.0; |
| 213 |
for (j = 0; j < 3; j++) |
| 214 |
d += (r->rop[j] - av->pos[j]) * |
| 215 |
(av->dir[j] + r->ron[j]); |
| 216 |
if (d*0.5 < -minarad*ambacc) |
| 217 |
continue; |
| 218 |
/* |
| 219 |
* Jittering final test reduces image artifacts. |
| 220 |
*/ |
| 221 |
wt = sqrt(e1) + sqrt(e2); |
| 222 |
wt *= .9 + .2*frandom(); |
| 223 |
if (wt > ambacc) |
| 224 |
continue; |
| 225 |
if (wt <= 1e-3) |
| 226 |
wt = 1e3; |
| 227 |
else |
| 228 |
wt = 1.0 / wt; |
| 229 |
wsum += wt; |
| 230 |
copycolor(ct, av->val); |
| 231 |
scalecolor(ct, wt); |
| 232 |
addcolor(acol, ct); |
| 233 |
} |
| 234 |
if (at->kid == NULL) |
| 235 |
return(wsum); |
| 236 |
/* do children */ |
| 237 |
s *= 0.5; |
| 238 |
for (i = 0; i < 8; i++) { |
| 239 |
for (j = 0; j < 3; j++) { |
| 240 |
ck0[j] = c0[j]; |
| 241 |
if (1<<j & i) |
| 242 |
ck0[j] += s; |
| 243 |
if (r->rop[j] < ck0[j] - OCTSCALE*s) |
| 244 |
break; |
| 245 |
if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s) |
| 246 |
break; |
| 247 |
} |
| 248 |
if (j == 3) |
| 249 |
wsum += sumambient(acol, r, at->kid+i, ck0, s); |
| 250 |
} |
| 251 |
return(wsum); |
| 252 |
} |
| 253 |
|
| 254 |
|
| 255 |
double |
| 256 |
makeambient(acol, r) /* make a new ambient value */ |
| 257 |
COLOR acol; |
| 258 |
register RAY *r; |
| 259 |
{ |
| 260 |
AMBVAL amb; |
| 261 |
|
| 262 |
amb.rad = doambient(acol, r); /* compute ambient */ |
| 263 |
if (amb.rad == 0.0) |
| 264 |
return(0.0); |
| 265 |
/* store it */ |
| 266 |
VCOPY(amb.pos, r->rop); |
| 267 |
VCOPY(amb.dir, r->ron); |
| 268 |
amb.lvl = r->rlvl; |
| 269 |
amb.weight = r->rweight; |
| 270 |
copycolor(amb.val, acol); |
| 271 |
/* insert into tree */ |
| 272 |
avinsert(&amb, &atrunk, thescene.cuorg, thescene.cusize); |
| 273 |
avsave(&amb); /* write to file */ |
| 274 |
return(amb.rad); |
| 275 |
} |
| 276 |
|
| 277 |
|
| 278 |
double |
| 279 |
doambient(acol, r) /* compute ambient component */ |
| 280 |
COLOR acol; |
| 281 |
register RAY *r; |
| 282 |
{ |
| 283 |
extern int ambcmp(); |
| 284 |
extern double sin(), cos(), sqrt(); |
| 285 |
int hlist[4]; |
| 286 |
double phi, xd, yd, zd; |
| 287 |
double b, b2; |
| 288 |
register AMBSAMP *div; |
| 289 |
AMBSAMP dnew; |
| 290 |
RAY ar; |
| 291 |
FVECT ux, uy; |
| 292 |
double arad; |
| 293 |
int ndivs, nt, np, ns, ne, i, j; |
| 294 |
register int k; |
| 295 |
|
| 296 |
setcolor(acol, 0.0, 0.0, 0.0); |
| 297 |
/* set number of divisions */ |
| 298 |
nt = sqrt(ambdiv * r->rweight * 0.5) + 0.5; |
| 299 |
np = 2 * nt; |
| 300 |
ndivs = nt * np; |
| 301 |
/* check first */ |
| 302 |
if (ndivs == 0 || rayorigin(&ar, r, AMBIENT, 0.5) < 0) |
| 303 |
return(0.0); |
| 304 |
/* set number of super-samples */ |
| 305 |
ns = ambssamp * r->rweight + 0.5; |
| 306 |
if (ns > 0) { |
| 307 |
div = (AMBSAMP *)malloc(ndivs*sizeof(AMBSAMP)); |
| 308 |
if (div == NULL) |
| 309 |
error(SYSTEM, "out of memory in doambient"); |
| 310 |
} else |
| 311 |
div = NULL; |
| 312 |
/* make axes */ |
| 313 |
uy[0] = uy[1] = uy[2] = 0.0; |
| 314 |
for (k = 0; k < 3; k++) |
| 315 |
if (r->ron[k] < 0.6 && r->ron[k] > -0.6) |
| 316 |
break; |
| 317 |
uy[k] = 1.0; |
| 318 |
fcross(ux, r->ron, uy); |
| 319 |
normalize(ux); |
| 320 |
fcross(uy, ux, r->ron); |
| 321 |
/* set up urand */ |
| 322 |
hlist[0] = r->rno; |
| 323 |
/* sample divisions */ |
| 324 |
arad = 0.0; |
| 325 |
ne = 0; |
| 326 |
for (i = 0; i < nt; i++) { |
| 327 |
hlist[1] = i; |
| 328 |
for (j = 0; j < np; j++) { |
| 329 |
rayorigin(&ar, r, AMBIENT, 0.5); /* pretested */ |
| 330 |
hlist[2] = j; |
| 331 |
hlist[3] = 0; |
| 332 |
zd = sqrt((i+urand(ilhash(hlist,4)))/nt); |
| 333 |
hlist[3] = 1; |
| 334 |
phi = 2.0*PI * (j+urand(ilhash(hlist,4)))/np; |
| 335 |
xd = cos(phi) * zd; |
| 336 |
yd = sin(phi) * zd; |
| 337 |
zd = sqrt(1.0 - zd*zd); |
| 338 |
for (k = 0; k < 3; k++) |
| 339 |
ar.rdir[k] = xd*ux[k]+yd*uy[k]+zd*r->ron[k]; |
| 340 |
dimlist[ndims++] = i*np + j + 38813; |
| 341 |
rayvalue(&ar); |
| 342 |
ndims--; |
| 343 |
if (ar.rot < FHUGE) |
| 344 |
arad += 1.0 / ar.rot; |
| 345 |
if (div != NULL) { /* save division */ |
| 346 |
div[ne].k = 0.0; |
| 347 |
copycolor(div[ne].v, ar.rcol); |
| 348 |
div[ne].n = 0; |
| 349 |
div[ne].t = i; div[ne].p = j; |
| 350 |
/* sum errors */ |
| 351 |
b = bright(ar.rcol); |
| 352 |
if (i > 0) { /* from above */ |
| 353 |
b2 = bright(div[ne-np].v) - b; |
| 354 |
b2 *= b2 * 0.25; |
| 355 |
div[ne].k += b2; |
| 356 |
div[ne].n++; |
| 357 |
div[ne-np].k += b2; |
| 358 |
div[ne-np].n++; |
| 359 |
} |
| 360 |
if (j > 0) { /* from behind */ |
| 361 |
b2 = bright(div[ne-1].v) - b; |
| 362 |
b2 *= b2 * 0.25; |
| 363 |
div[ne].k += b2; |
| 364 |
div[ne].n++; |
| 365 |
div[ne-1].k += b2; |
| 366 |
div[ne-1].n++; |
| 367 |
} |
| 368 |
if (j == np-1) { /* around */ |
| 369 |
b2 = bright(div[ne-(np-1)].v) - b; |
| 370 |
b2 *= b2 * 0.25; |
| 371 |
div[ne].k += b2; |
| 372 |
div[ne].n++; |
| 373 |
div[ne-(np-1)].k += b2; |
| 374 |
div[ne-(np-1)].n++; |
| 375 |
} |
| 376 |
ne++; |
| 377 |
} else |
| 378 |
addcolor(acol, ar.rcol); |
| 379 |
} |
| 380 |
} |
| 381 |
for (k = 0; k < ne; k++) { /* compute errors */ |
| 382 |
if (div[k].n > 1) |
| 383 |
div[k].k /= div[k].n; |
| 384 |
div[k].n = 1; |
| 385 |
} |
| 386 |
/* sort the divisions */ |
| 387 |
qsort(div, ne, sizeof(AMBSAMP), ambcmp); |
| 388 |
/* skim excess */ |
| 389 |
while (ne > ns) { |
| 390 |
ne--; |
| 391 |
addcolor(acol, div[ne].v); |
| 392 |
} |
| 393 |
/* super-sample */ |
| 394 |
for (i = ns; i > 0; i--) { |
| 395 |
rayorigin(&ar, r, AMBIENT, 0.5); /* pretested */ |
| 396 |
hlist[1] = div[0].t; |
| 397 |
hlist[2] = div[0].p; |
| 398 |
hlist[3] = 0; |
| 399 |
zd = sqrt((div[0].t+urand(ilhash(hlist,4)+div[0].n))/nt); |
| 400 |
hlist[3] = 1; |
| 401 |
phi = 2.0*PI * (div[0].p+urand(ilhash(hlist,4)+div[0].n))/np; |
| 402 |
xd = cos(phi) * zd; |
| 403 |
yd = sin(phi) * zd; |
| 404 |
zd = sqrt(1.0 - zd*zd); |
| 405 |
for (k = 0; k < 3; k++) |
| 406 |
ar.rdir[k] = xd*ux[k]+yd*uy[k]+zd*r->ron[k]; |
| 407 |
dimlist[ndims++] = div[0].t*np + div[0].p + 38813; |
| 408 |
rayvalue(&ar); |
| 409 |
ndims--; |
| 410 |
rayvalue(&ar); |
| 411 |
if (ar.rot < FHUGE) |
| 412 |
arad += 1.0 / ar.rot; |
| 413 |
/* recompute error */ |
| 414 |
copycolor(dnew.v, div[0].v); |
| 415 |
addcolor(dnew.v, ar.rcol); |
| 416 |
dnew.n = div[0].n + 1; |
| 417 |
dnew.t = div[0].t; dnew.p = div[0].p; |
| 418 |
b2 = bright(dnew.v)/dnew.n - bright(ar.rcol); |
| 419 |
b2 = b2*b2 + div[0].k*(div[0].n*div[0].n); |
| 420 |
dnew.k = b2/(dnew.n*dnew.n); |
| 421 |
/* reinsert */ |
| 422 |
for (k = 0; k < ne-1 && dnew.k < div[k+1].k; k++) |
| 423 |
copystruct(&div[k], &div[k+1]); |
| 424 |
copystruct(&div[k], &dnew); |
| 425 |
|
| 426 |
if (ne >= i) { /* extract darkest division */ |
| 427 |
ne--; |
| 428 |
if (div[ne].n > 1) { |
| 429 |
b = 1.0/div[ne].n; |
| 430 |
scalecolor(div[ne].v, b); |
| 431 |
div[ne].n = 1; |
| 432 |
} |
| 433 |
addcolor(acol, div[ne].v); |
| 434 |
} |
| 435 |
} |
| 436 |
scalecolor(acol, 1.0/ndivs); |
| 437 |
if (arad <= FTINY) |
| 438 |
arad = FHUGE; |
| 439 |
else |
| 440 |
arad = (ndivs+ns) / arad / sqrt(r->rweight); |
| 441 |
if (arad > maxarad) |
| 442 |
arad = maxarad; |
| 443 |
else if (arad < minarad) |
| 444 |
arad = minarad; |
| 445 |
if (div != NULL) |
| 446 |
free((char *)div); |
| 447 |
return(arad); |
| 448 |
} |
| 449 |
|
| 450 |
|
| 451 |
static int |
| 452 |
ambcmp(d1, d2) /* decreasing order */ |
| 453 |
AMBSAMP *d1, *d2; |
| 454 |
{ |
| 455 |
if (d1->k < d2->k) |
| 456 |
return(1); |
| 457 |
if (d1->k > d2->k) |
| 458 |
return(-1); |
| 459 |
return(0); |
| 460 |
} |
| 461 |
|
| 462 |
|
| 463 |
static |
| 464 |
avsave(av) /* save an ambient value */ |
| 465 |
AMBVAL *av; |
| 466 |
{ |
| 467 |
#ifdef AMBFLUSH |
| 468 |
static int nunflshed = 0; |
| 469 |
#endif |
| 470 |
if (ambfp == NULL) |
| 471 |
return; |
| 472 |
if (fwrite((char *)av, sizeof(AMBVAL), 1, ambfp) != 1) |
| 473 |
goto writerr; |
| 474 |
#ifdef AMBFLUSH |
| 475 |
if (++nunflshed >= AMBFLUSH) { |
| 476 |
if (fflush(ambfp) == EOF) |
| 477 |
goto writerr; |
| 478 |
nunflshed = 0; |
| 479 |
} |
| 480 |
#endif |
| 481 |
return; |
| 482 |
writerr: |
| 483 |
error(SYSTEM, "error writing ambient file"); |
| 484 |
} |
| 485 |
|
| 486 |
|
| 487 |
static |
| 488 |
avinsert(aval, at, c0, s) /* insert ambient value in a tree */ |
| 489 |
AMBVAL *aval; |
| 490 |
register AMBTREE *at; |
| 491 |
FVECT c0; |
| 492 |
double s; |
| 493 |
{ |
| 494 |
FVECT ck0; |
| 495 |
int branch; |
| 496 |
register AMBVAL *av; |
| 497 |
register int i; |
| 498 |
|
| 499 |
if ((av = newambval()) == NULL) |
| 500 |
goto memerr; |
| 501 |
copystruct(av, aval); |
| 502 |
VCOPY(ck0, c0); |
| 503 |
while (s*(OCTSCALE/2) > av->rad*ambacc) { |
| 504 |
if (at->kid == NULL) |
| 505 |
if ((at->kid = newambtree()) == NULL) |
| 506 |
goto memerr; |
| 507 |
s *= 0.5; |
| 508 |
branch = 0; |
| 509 |
for (i = 0; i < 3; i++) |
| 510 |
if (av->pos[i] > ck0[i] + s) { |
| 511 |
ck0[i] += s; |
| 512 |
branch |= 1 << i; |
| 513 |
} |
| 514 |
at = at->kid + branch; |
| 515 |
} |
| 516 |
av->next = at->alist; |
| 517 |
at->alist = av; |
| 518 |
return; |
| 519 |
memerr: |
| 520 |
error(SYSTEM, "out of memory in avinsert"); |
| 521 |
} |
