1 |
/* |
2 |
================================================================== |
3 |
Photon map support routines for scattering by materials. |
4 |
|
5 |
Roland Schregle (roland.schregle@{hslu.ch, gmail.com}) |
6 |
(c) Fraunhofer Institute for Solar Energy Systems, |
7 |
(c) Lucerne University of Applied Sciences and Arts, |
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supported by the Swiss National Science Foundation (SNSF, #147053) |
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================================================================== |
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|
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$Id: pmapmat.c,v 2.2 2015/04/22 15:50:44 rschregle Exp $ |
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*/ |
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|
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|
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|
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#include "pmapmat.h" |
17 |
#include "pmapdata.h" |
18 |
#include "pmaprand.h" |
19 |
#include "otypes.h" |
20 |
#include "data.h" |
21 |
#include "func.h" |
22 |
#include "bsdf.h" |
23 |
#include <math.h> |
24 |
|
25 |
|
26 |
|
27 |
/* Stuff ripped off from material modules */ |
28 |
#define MAXITER 10 |
29 |
#define SP_REFL 01 |
30 |
#define SP_TRAN 02 |
31 |
#define SP_PURE 04 |
32 |
#define SP_FLAT 010 |
33 |
#define SP_BADU 040 |
34 |
#define MLAMBDA 500 |
35 |
#define RINDEX 1.52 |
36 |
#define FRESNE(ci) (exp(-5.85*(ci)) - 0.00287989916) |
37 |
|
38 |
|
39 |
|
40 |
typedef struct { |
41 |
OBJREC *mp; |
42 |
RAY *rp; |
43 |
short specfl; |
44 |
COLOR mcolor, scolor; |
45 |
FVECT vrefl, prdir, pnorm; |
46 |
double alpha2, rdiff, rspec, trans, tdiff, tspec, pdot; |
47 |
} NORMDAT; |
48 |
|
49 |
typedef struct { |
50 |
OBJREC *mp; |
51 |
RAY *rp; |
52 |
short specfl; |
53 |
COLOR mcolor, scolor; |
54 |
FVECT vrefl, prdir, u, v, pnorm; |
55 |
double u_alpha, v_alpha, rdiff, rspec, trans, tdiff, tspec, pdot; |
56 |
} ANISODAT; |
57 |
|
58 |
typedef struct { |
59 |
OBJREC *mp; |
60 |
RAY *pr; |
61 |
FVECT pnorm; |
62 |
FVECT vray; |
63 |
double sr_vpsa [2]; |
64 |
RREAL toloc [3][3]; |
65 |
RREAL fromloc [3][3]; |
66 |
double thick; |
67 |
SDData *sd; |
68 |
COLOR runsamp; |
69 |
COLOR rdiff; |
70 |
COLOR tunsamp; |
71 |
COLOR tdiff; |
72 |
} BSDFDAT; |
73 |
|
74 |
|
75 |
|
76 |
extern const SDCDst SDemptyCD; |
77 |
|
78 |
/* Per-material scattering function dispatch table; return value is usually |
79 |
* zero, indicating photon termination */ |
80 |
int (*photonScatter [NUMOTYPE]) (OBJREC*, RAY*); |
81 |
|
82 |
/* List of antimatter sensor modifier names and associated object set */ |
83 |
char *photonSensorList [MAXSET + 1] = {NULL}; |
84 |
static OBJECT photonSensorSet [MAXSET + 1] = {0}; |
85 |
|
86 |
|
87 |
|
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/* ================ General support routines ================ */ |
89 |
|
90 |
|
91 |
void photonRay (const RAY *rayIn, RAY *rayOut, |
92 |
int rayOutType, COLOR fluxAtten) |
93 |
/* Spawn a new photon ray from a previous one; this is effectively a |
94 |
* customised rayorigin(). |
95 |
* A SPECULAR rayOutType flags this photon as _caustic_ for subsequent hits. |
96 |
* It is preserved for transferred rays (of type PMAP_XFER). |
97 |
* fluxAtten specifies the RGB attenuation of the photon flux effected by |
98 |
* the scattering material. The outgoing flux is then normalised to maintain |
99 |
* a uniform average of 1 over RGB. If fluxAtten == NULL, the flux remains |
100 |
* unchanged for the outgoing photon. fluxAtten is ignored for transferred |
101 |
* rays. |
102 |
* The ray direction is preserved for transferred rays, and undefined for |
103 |
* scattered rays and must be subsequently set by the caller. */ |
104 |
{ |
105 |
rayorigin(rayOut, rayOutType, rayIn, NULL); |
106 |
|
107 |
/* Transfer flux */ |
108 |
copycolor(rayOut -> rcol, rayIn -> rcol); |
109 |
|
110 |
/* Copy caustic flag & direction for transferred rays */ |
111 |
if (rayOutType == PMAP_XFER) { |
112 |
/* rayOut -> rtype |= rayIn -> rtype & SPECULAR; */ |
113 |
rayOut -> rtype |= rayIn -> rtype; |
114 |
VCOPY(rayOut -> rdir, rayIn -> rdir); |
115 |
} |
116 |
else if (fluxAtten) { |
117 |
/* Attenuate and normalise flux for scattered rays */ |
118 |
multcolor(rayOut -> rcol, fluxAtten); |
119 |
colorNorm(rayOut -> rcol); |
120 |
} |
121 |
|
122 |
/* Propagate index of emitting light source */ |
123 |
rayOut -> rsrc = rayIn -> rsrc; |
124 |
} |
125 |
|
126 |
|
127 |
|
128 |
static void addPhotons (const RAY *r) |
129 |
/* Insert photon hits, where applicable */ |
130 |
{ |
131 |
if (!r -> rlvl) |
132 |
/* Add direct photon map at primary hitpoint */ |
133 |
addPhoton(directPmap, r); |
134 |
else { |
135 |
/* Add global or precomputed photon map at indirect hitpoint */ |
136 |
addPhoton(preCompPmap ? preCompPmap : globalPmap, r); |
137 |
|
138 |
/* Store caustic photon if specular flag set */ |
139 |
if (PMAP_CAUSTICRAY(r)) |
140 |
addPhoton(causticPmap, r); |
141 |
|
142 |
/* Store in contribution photon map */ |
143 |
addPhoton(contribPmap, r); |
144 |
} |
145 |
} |
146 |
|
147 |
|
148 |
|
149 |
void getPhotonSensors (char **sensorList) |
150 |
/* Find antimatter geometry declared as photon sensors */ |
151 |
{ |
152 |
OBJECT i; |
153 |
OBJREC *obj; |
154 |
char **lp; |
155 |
|
156 |
/* Init sensor set */ |
157 |
photonSensorSet [0] = 0; |
158 |
|
159 |
if (!sensorList [0]) |
160 |
return; |
161 |
|
162 |
for (i = 0; i < nobjects; i++) { |
163 |
obj = objptr(i); |
164 |
|
165 |
/* Insert object in sensor set if it's in the specified sensor list |
166 |
* and of type antimatter */ |
167 |
for (lp = sensorList; *lp; lp++) { |
168 |
if (!strcmp(obj -> oname, *lp)) { |
169 |
if (obj -> otype != MAT_CLIP) { |
170 |
sprintf(errmsg, "photon sensor modifier %s is not antimatter", |
171 |
obj -> oname); |
172 |
error(USER, errmsg); |
173 |
} |
174 |
|
175 |
if (photonSensorSet [0] >= AMBLLEN) |
176 |
error(USER, "too many photon sensor modifiers"); |
177 |
|
178 |
insertelem(photonSensorSet, i); |
179 |
} |
180 |
} |
181 |
} |
182 |
|
183 |
if (!photonSensorSet [0]) |
184 |
error(USER, "no photon sensors found"); |
185 |
} |
186 |
|
187 |
|
188 |
|
189 |
/* ================ Material specific scattering routines ================ */ |
190 |
|
191 |
|
192 |
static int isoSpecPhotonScatter (NORMDAT *nd, RAY *rayOut) |
193 |
/* Generate direction for isotropically specularly reflected |
194 |
or transmitted ray. Returns 1 if successful. */ |
195 |
{ |
196 |
FVECT u, v, h; |
197 |
RAY *rayIn = nd -> rp; |
198 |
double d, d2, sinp, cosp; |
199 |
int niter, i = 0; |
200 |
|
201 |
/* Set up sample coordinates */ |
202 |
do { |
203 |
v [0] = v [1] = v [2] = 0; |
204 |
v [i++] = 1; |
205 |
fcross(u, v, nd -> pnorm); |
206 |
} while (normalize(u) < FTINY); |
207 |
|
208 |
fcross(v, nd -> pnorm, u); |
209 |
|
210 |
if (nd -> specfl & SP_REFL) { |
211 |
/* Specular reflection; make MAXITER attempts at getting a ray */ |
212 |
|
213 |
for (niter = 0; niter < MAXITER; niter++) { |
214 |
d = 2 * PI * pmapRandom(scatterState); |
215 |
cosp = cos(d); |
216 |
sinp = sin(d); |
217 |
d2 = pmapRandom(scatterState); |
218 |
d = d2 <= FTINY ? 1 : sqrt(nd -> alpha2 * -log(d2)); |
219 |
|
220 |
for (i = 0; i < 3; i++) |
221 |
h [i] = nd -> pnorm [i] + d * (cosp * u [i] + sinp * v [i]); |
222 |
|
223 |
d = -2 * DOT(h, rayIn -> rdir) / (1 + d * d); |
224 |
VSUM(rayOut -> rdir, rayIn -> rdir, h, d); |
225 |
|
226 |
if (DOT(rayOut -> rdir, rayIn -> ron) > FTINY) |
227 |
return 1; |
228 |
} |
229 |
|
230 |
return 0; |
231 |
} |
232 |
|
233 |
else { |
234 |
/* Specular transmission; make MAXITER attempts at getting a ray */ |
235 |
|
236 |
for (niter = 0; niter < MAXITER; niter++) { |
237 |
d = 2 * PI * pmapRandom(scatterState); |
238 |
cosp = cos(d); |
239 |
sinp = sin(d); |
240 |
d2 = pmapRandom(scatterState); |
241 |
d = d2 <= FTINY ? 1 : sqrt(-log(d2) * nd -> alpha2); |
242 |
|
243 |
for (i = 0; i < 3; i++) |
244 |
rayOut -> rdir [i] = nd -> prdir [i] + |
245 |
d * (cosp * u [i] + sinp * v [i]); |
246 |
|
247 |
if (DOT(rayOut -> rdir, rayIn -> ron) < -FTINY) { |
248 |
normalize(rayOut -> rdir); |
249 |
return 1; |
250 |
} |
251 |
} |
252 |
|
253 |
return 0; |
254 |
} |
255 |
} |
256 |
|
257 |
|
258 |
|
259 |
static void diffPhotonScatter (FVECT normal, RAY* rayOut) |
260 |
/* Generate cosine-weighted direction for diffuse ray */ |
261 |
{ |
262 |
const RREAL cosThetaSqr = pmapRandom(scatterState), |
263 |
cosTheta = sqrt(cosThetaSqr), |
264 |
sinTheta = sqrt(1 - cosThetaSqr), |
265 |
phi = 2 * PI * pmapRandom(scatterState), |
266 |
du = cos(phi) * sinTheta, dv = sin(phi) * sinTheta; |
267 |
FVECT u, v; |
268 |
int i = 0; |
269 |
|
270 |
/* Set up sample coordinates */ |
271 |
do { |
272 |
v [0] = v [1] = v [2] = 0; |
273 |
v [i++] = 1; |
274 |
fcross(u, v, normal); |
275 |
} while (normalize(u) < FTINY); |
276 |
|
277 |
fcross(v, normal, u); |
278 |
|
279 |
/* Convert theta & phi to cartesian */ |
280 |
for (i = 0; i < 3; i++) |
281 |
rayOut -> rdir [i] = du * u [i] + dv * v [i] + cosTheta * normal [i]; |
282 |
|
283 |
normalize(rayOut -> rdir); |
284 |
} |
285 |
|
286 |
|
287 |
|
288 |
static int normalPhotonScatter (OBJREC *mat, RAY *rayIn) |
289 |
/* Generate new photon ray for isotropic material and recurse */ |
290 |
{ |
291 |
NORMDAT nd; |
292 |
int i, hastexture; |
293 |
float xi, albedo, prdiff, ptdiff, prspec, ptspec; |
294 |
double d, fresnel; |
295 |
RAY rayOut; |
296 |
|
297 |
if (mat -> oargs.nfargs != (mat -> otype == MAT_TRANS ? 7 : 5)) |
298 |
objerror(mat, USER, "bad number of arguments"); |
299 |
|
300 |
/* Check for back side; reorient if back is visible */ |
301 |
if (rayIn -> rod < 0) |
302 |
if (!backvis && mat -> otype != MAT_TRANS) |
303 |
return 0; |
304 |
else { |
305 |
/* Get modifiers */ |
306 |
raytexture(rayIn, mat -> omod); |
307 |
flipsurface(rayIn); |
308 |
} |
309 |
else raytexture(rayIn, mat -> omod); |
310 |
|
311 |
nd.rp = rayIn; |
312 |
|
313 |
/* Get material color */ |
314 |
copycolor(nd.mcolor, mat -> oargs.farg); |
315 |
|
316 |
/* Get roughness */ |
317 |
nd.specfl = 0; |
318 |
nd.alpha2 = mat -> oargs.farg [4]; |
319 |
|
320 |
if ((nd.alpha2 *= nd.alpha2) <= FTINY) |
321 |
nd.specfl |= SP_PURE; |
322 |
|
323 |
if (rayIn -> ro != NULL && isflat(rayIn -> ro -> otype)) |
324 |
nd.specfl |= SP_FLAT; |
325 |
|
326 |
/* Perturb normal */ |
327 |
if ((hastexture = DOT(rayIn -> pert, rayIn -> pert)) > sqr(FTINY)) |
328 |
nd.pdot = raynormal(nd.pnorm, rayIn); |
329 |
else { |
330 |
VCOPY(nd.pnorm, rayIn -> ron); |
331 |
nd.pdot = rayIn -> rod; |
332 |
} |
333 |
|
334 |
nd.pdot = max(nd.pdot, .001); |
335 |
|
336 |
/* Modify material color */ |
337 |
multcolor(nd.mcolor, rayIn -> pcol); |
338 |
nd.rspec = mat -> oargs.farg [3]; |
339 |
|
340 |
/* Approximate Fresnel term */ |
341 |
if (nd.specfl & SP_PURE && nd.rspec > FTINY) { |
342 |
fresnel = FRESNE(rayIn -> rod); |
343 |
nd.rspec += fresnel * (1 - nd.rspec); |
344 |
} |
345 |
else fresnel = 0; |
346 |
|
347 |
/* Transmission params */ |
348 |
if (mat -> otype == MAT_TRANS) { |
349 |
nd.trans = mat -> oargs.farg [5] * (1 - nd.rspec); |
350 |
nd.tspec = nd.trans * mat -> oargs.farg [6]; |
351 |
nd.tdiff = nd.trans - nd.tspec; |
352 |
} |
353 |
else nd.tdiff = nd.tspec = nd.trans = 0; |
354 |
|
355 |
/* Specular reflection params */ |
356 |
if (nd.rspec > FTINY) { |
357 |
/* Specular color */ |
358 |
if (mat -> otype != MAT_METAL) |
359 |
setcolor(nd.scolor, nd.rspec, nd.rspec, nd.rspec); |
360 |
else if (fresnel > FTINY) { |
361 |
d = nd.rspec * (1 - fresnel); |
362 |
for (i = 0; i < 3; i++) |
363 |
nd.scolor [i] = fresnel + nd.mcolor [i] * d; |
364 |
} |
365 |
else { |
366 |
copycolor(nd.scolor, nd.mcolor); |
367 |
scalecolor(nd.scolor, nd.rspec); |
368 |
} |
369 |
} |
370 |
else setcolor(nd.scolor, 0, 0, 0); |
371 |
|
372 |
/* Diffuse reflection params */ |
373 |
nd.rdiff = 1 - nd.trans - nd.rspec; |
374 |
|
375 |
/* Set up probabilities */ |
376 |
prdiff = ptdiff = ptspec = colorAvg(nd.mcolor); |
377 |
prdiff *= nd.rdiff; |
378 |
ptdiff *= nd.tdiff; |
379 |
prspec = colorAvg(nd.scolor); |
380 |
ptspec *= nd.tspec; |
381 |
albedo = prdiff + ptdiff + prspec + ptspec; |
382 |
|
383 |
/* Insert direct and indirect photon hits if diffuse component */ |
384 |
if (prdiff > FTINY || ptdiff > FTINY) |
385 |
addPhotons(rayIn); |
386 |
|
387 |
xi = pmapRandom(rouletteState); |
388 |
|
389 |
if (xi > albedo) |
390 |
/* Absorbed */ |
391 |
return 0; |
392 |
|
393 |
if (xi > (albedo -= prspec)) { |
394 |
/* Specular reflection */ |
395 |
nd.specfl |= SP_REFL; |
396 |
|
397 |
if (nd.specfl & SP_PURE) { |
398 |
/* Perfect specular reflection */ |
399 |
for (i = 0; i < 3; i++) { |
400 |
/* Reflected ray */ |
401 |
nd.vrefl [i] = rayIn -> rdir [i] + 2 * nd.pdot * nd.pnorm [i]; |
402 |
} |
403 |
|
404 |
/* Penetration? */ |
405 |
if (hastexture && DOT(nd.vrefl, rayIn -> ron) <= FTINY) |
406 |
for (i = 0; i < 3; i++) { |
407 |
/* Safety measure */ |
408 |
nd.vrefl [i] = rayIn -> rdir [i] + |
409 |
2 * rayIn -> rod * rayIn -> ron [i]; |
410 |
} |
411 |
|
412 |
VCOPY(rayOut.rdir, nd.vrefl); |
413 |
} |
414 |
|
415 |
else if (!isoSpecPhotonScatter(&nd, &rayOut)) |
416 |
return 0; |
417 |
|
418 |
photonRay(rayIn, &rayOut, PMAP_SPECREFL, nd.scolor); |
419 |
} |
420 |
|
421 |
else if (xi > (albedo -= ptspec)) { |
422 |
/* Specular transmission */ |
423 |
nd.specfl |= SP_TRAN; |
424 |
|
425 |
if (hastexture) { |
426 |
/* Perturb */ |
427 |
for (i = 0; i < 3; i++) |
428 |
nd.prdir [i] = rayIn -> rdir [i] - rayIn -> pert [i]; |
429 |
|
430 |
if (DOT(nd.prdir, rayIn -> ron) < -FTINY) |
431 |
normalize(nd.prdir); |
432 |
else VCOPY(nd.prdir, rayIn -> rdir); |
433 |
} |
434 |
else VCOPY(nd.prdir, rayIn -> rdir); |
435 |
|
436 |
if ((nd.specfl & (SP_TRAN | SP_PURE)) == (SP_TRAN | SP_PURE)) |
437 |
/* Perfect specular transmission */ |
438 |
VCOPY(rayOut.rdir, nd.prdir); |
439 |
else if (!isoSpecPhotonScatter(&nd, &rayOut)) |
440 |
return 0; |
441 |
|
442 |
photonRay(rayIn, &rayOut, PMAP_SPECTRANS, nd.mcolor); |
443 |
} |
444 |
|
445 |
else if (xi > (albedo -= prdiff)) { |
446 |
/* Diffuse reflection */ |
447 |
photonRay(rayIn, &rayOut, PMAP_DIFFREFL, nd.mcolor); |
448 |
diffPhotonScatter(hastexture ? nd.pnorm : rayIn -> ron, &rayOut); |
449 |
} |
450 |
|
451 |
else { |
452 |
/* Diffuse transmission */ |
453 |
flipsurface(rayIn); |
454 |
photonRay(rayIn, &rayOut, PMAP_DIFFTRANS, nd.mcolor); |
455 |
|
456 |
if (hastexture) { |
457 |
FVECT bnorm; |
458 |
bnorm [0] = -nd.pnorm [0]; |
459 |
bnorm [1] = -nd.pnorm [1]; |
460 |
bnorm [2] = -nd.pnorm [2]; |
461 |
diffPhotonScatter(bnorm, &rayOut); |
462 |
} |
463 |
else diffPhotonScatter(rayIn -> ron, &rayOut); |
464 |
} |
465 |
|
466 |
tracePhoton(&rayOut); |
467 |
return 0; |
468 |
} |
469 |
|
470 |
|
471 |
|
472 |
static void getacoords (ANISODAT *np) |
473 |
/* Set up coordinate system for anisotropic sampling; cloned from aniso.c */ |
474 |
{ |
475 |
MFUNC *mf; |
476 |
int i; |
477 |
|
478 |
mf = getfunc(np->mp, 3, 0x7, 1); |
479 |
setfunc(np->mp, np->rp); |
480 |
errno = 0; |
481 |
|
482 |
for (i = 0; i < 3; i++) |
483 |
np->u[i] = evalue(mf->ep[i]); |
484 |
|
485 |
if ((errno == EDOM) | (errno == ERANGE)) { |
486 |
objerror(np->mp, WARNING, "compute error"); |
487 |
np->specfl |= SP_BADU; |
488 |
return; |
489 |
} |
490 |
|
491 |
if (mf->fxp != &unitxf) |
492 |
multv3(np->u, np->u, mf->fxp->xfm); |
493 |
|
494 |
fcross(np->v, np->pnorm, np->u); |
495 |
|
496 |
if (normalize(np->v) == 0.0) { |
497 |
objerror(np->mp, WARNING, "illegal orientation vector"); |
498 |
np->specfl |= SP_BADU; |
499 |
return; |
500 |
} |
501 |
|
502 |
fcross(np->u, np->v, np->pnorm); |
503 |
} |
504 |
|
505 |
|
506 |
|
507 |
static int anisoSpecPhotonScatter (ANISODAT *nd, RAY *rayOut) |
508 |
/* Generate direction for anisotropically specularly reflected |
509 |
or transmitted ray. Returns 1 if successful. */ |
510 |
{ |
511 |
FVECT h; |
512 |
double d, d2, sinp, cosp; |
513 |
int niter, i; |
514 |
RAY *rayIn = nd -> rp; |
515 |
|
516 |
if (rayIn -> ro != NULL && isflat(rayIn -> ro -> otype)) |
517 |
nd -> specfl |= SP_FLAT; |
518 |
|
519 |
/* set up coordinates */ |
520 |
getacoords(nd); |
521 |
|
522 |
if (rayOut -> rtype & TRANS) { |
523 |
/* Specular transmission */ |
524 |
|
525 |
if (DOT(rayIn -> pert, rayIn -> pert) <= FTINY * FTINY) |
526 |
VCOPY(nd -> prdir, rayIn -> rdir); |
527 |
else { |
528 |
/* perturb */ |
529 |
for (i = 0; i < 3; i++) |
530 |
nd -> prdir [i] = rayIn -> rdir [i] - rayIn -> pert [i]; |
531 |
|
532 |
if (DOT(nd -> prdir, rayIn -> ron) < -FTINY) |
533 |
normalize(nd -> prdir); |
534 |
else VCOPY(nd -> prdir, rayIn -> rdir); |
535 |
} |
536 |
|
537 |
/* Make MAXITER attempts at getting a ray */ |
538 |
for (niter = 0; niter < MAXITER; niter++) { |
539 |
d = 2 * PI * pmapRandom(scatterState); |
540 |
cosp = cos(d) * nd -> u_alpha; |
541 |
sinp = sin(d) * nd -> v_alpha; |
542 |
d = sqrt(sqr(cosp) + sqr(sinp)); |
543 |
cosp /= d; |
544 |
sinp /= d; |
545 |
d2 = pmapRandom(scatterState); |
546 |
d = d2 <= FTINY ? 1 |
547 |
: sqrt(-log(d2) / |
548 |
(sqr(cosp) / sqr(nd -> u_alpha) + |
549 |
sqr(sinp) / (nd -> v_alpha * nd -> u_alpha))); |
550 |
|
551 |
for (i = 0; i < 3; i++) |
552 |
rayOut -> rdir [i] = nd -> prdir [i] + d * |
553 |
(cosp * nd -> u [i] + sinp * nd -> v [i]); |
554 |
|
555 |
if (DOT(rayOut -> rdir, rayIn -> ron) < -FTINY) { |
556 |
normalize(rayOut -> rdir); |
557 |
return 1; |
558 |
} |
559 |
} |
560 |
|
561 |
return 0; |
562 |
} |
563 |
|
564 |
else { |
565 |
/* Specular reflection */ |
566 |
|
567 |
/* Make MAXITER attempts at getting a ray */ |
568 |
for (niter = 0; niter < MAXITER; niter++) { |
569 |
d = 2 * PI * pmapRandom(scatterState); |
570 |
cosp = cos(d) * nd -> u_alpha; |
571 |
sinp = sin(d) * nd -> v_alpha; |
572 |
d = sqrt(sqr(cosp) + sqr(sinp)); |
573 |
cosp /= d; |
574 |
sinp /= d; |
575 |
d2 = pmapRandom(scatterState); |
576 |
d = d2 <= FTINY ? 1 |
577 |
: sqrt(-log(d2) / |
578 |
(sqr(cosp) / sqr(nd -> u_alpha) + |
579 |
sqr(sinp) / (nd -> v_alpha * nd -> v_alpha))); |
580 |
|
581 |
for (i = 0; i < 3; i++) |
582 |
h [i] = nd -> pnorm [i] + |
583 |
d * (cosp * nd -> u [i] + sinp * nd -> v [i]); |
584 |
|
585 |
d = -2 * DOT(h, rayIn -> rdir) / (1 + d * d); |
586 |
VSUM(rayOut -> rdir, rayIn -> rdir, h, d); |
587 |
|
588 |
if (DOT(rayOut -> rdir, rayIn -> ron) > FTINY) |
589 |
return 1; |
590 |
} |
591 |
|
592 |
return 0; |
593 |
} |
594 |
} |
595 |
|
596 |
|
597 |
|
598 |
static int anisoPhotonScatter (OBJREC *mat, RAY *rayIn) |
599 |
/* Generate new photon ray for anisotropic material and recurse */ |
600 |
{ |
601 |
ANISODAT nd; |
602 |
float xi, albedo, prdiff, ptdiff, prspec, ptspec; |
603 |
RAY rayOut; |
604 |
|
605 |
if (mat -> oargs.nfargs != (mat -> otype == MAT_TRANS2 ? 8 : 6)) |
606 |
objerror(mat, USER, "bad number of real arguments"); |
607 |
|
608 |
nd.rp = rayIn; |
609 |
nd.mp = objptr(rayIn -> ro -> omod); |
610 |
|
611 |
/* get material color */ |
612 |
copycolor(nd.mcolor, mat -> oargs.farg); |
613 |
|
614 |
/* get roughness */ |
615 |
nd.specfl = 0; |
616 |
nd.u_alpha = mat -> oargs.farg [4]; |
617 |
nd.v_alpha = mat -> oargs.farg [5]; |
618 |
if (nd.u_alpha < FTINY || nd.v_alpha <= FTINY) |
619 |
objerror(mat, USER, "roughness too small"); |
620 |
|
621 |
/* check for back side; reorient if back is visible */ |
622 |
if (rayIn -> rod < 0) |
623 |
if (!backvis && mat -> otype != MAT_TRANS2) |
624 |
return 0; |
625 |
else { |
626 |
/* get modifiers */ |
627 |
raytexture(rayIn, mat -> omod); |
628 |
flipsurface(rayIn); |
629 |
} |
630 |
else raytexture(rayIn, mat -> omod); |
631 |
|
632 |
/* perturb normal */ |
633 |
nd.pdot = max(raynormal(nd.pnorm, rayIn), .001); |
634 |
|
635 |
/* modify material color */ |
636 |
multcolor(nd.mcolor, rayIn -> pcol); |
637 |
nd.rspec = mat -> oargs.farg [3]; |
638 |
|
639 |
/* transmission params */ |
640 |
if (mat -> otype == MAT_TRANS2) { |
641 |
nd.trans = mat -> oargs.farg [6] * (1 - nd.rspec); |
642 |
nd.tspec = nd.trans * mat -> oargs.farg [7]; |
643 |
nd.tdiff = nd.trans - nd.tspec; |
644 |
if (nd.tspec > FTINY) |
645 |
nd.specfl |= SP_TRAN; |
646 |
} |
647 |
else nd.tdiff = nd.tspec = nd.trans = 0; |
648 |
|
649 |
/* specular reflection params */ |
650 |
if (nd.rspec > FTINY) { |
651 |
nd.specfl |= SP_REFL; |
652 |
|
653 |
/* comput e specular color */ |
654 |
if (mat -> otype == MAT_METAL2) |
655 |
copycolor(nd.scolor, nd.mcolor); |
656 |
else setcolor(nd.scolor, 1, 1, 1); |
657 |
|
658 |
scalecolor(nd.scolor, nd.rspec); |
659 |
} |
660 |
else setcolor(nd.scolor, 0, 0, 0); |
661 |
|
662 |
/* diffuse reflection params */ |
663 |
nd.rdiff = 1 - nd.trans - nd.rspec; |
664 |
|
665 |
/* Set up probabilities */ |
666 |
prdiff = ptdiff = ptspec = colorAvg(nd.mcolor); |
667 |
prdiff *= nd.rdiff; |
668 |
ptdiff *= nd.tdiff; |
669 |
prspec = colorAvg(nd.scolor); |
670 |
ptspec *= nd.tspec; |
671 |
albedo = prdiff + ptdiff + prspec + ptspec; |
672 |
|
673 |
/* Insert direct and indirect photon hits if diffuse component */ |
674 |
if (prdiff > FTINY || ptdiff > FTINY) |
675 |
addPhotons(rayIn); |
676 |
|
677 |
xi = pmapRandom(rouletteState); |
678 |
|
679 |
if (xi > albedo) |
680 |
/* Absorbed */ |
681 |
return 0; |
682 |
|
683 |
if (xi > (albedo -= prspec)) |
684 |
/* Specular reflection */ |
685 |
if (!(nd.specfl & SP_BADU)) { |
686 |
photonRay(rayIn, &rayOut, PMAP_SPECREFL, nd.scolor); |
687 |
|
688 |
if (!anisoSpecPhotonScatter(&nd, &rayOut)) |
689 |
return 0; |
690 |
} |
691 |
else return 0; |
692 |
|
693 |
else if (xi > (albedo -= ptspec)) |
694 |
/* Specular transmission */ |
695 |
|
696 |
if (!(nd.specfl & SP_BADU)) { |
697 |
/* Specular transmission */ |
698 |
photonRay(rayIn, &rayOut, PMAP_SPECTRANS, nd.mcolor); |
699 |
|
700 |
if (!anisoSpecPhotonScatter(&nd, &rayOut)) |
701 |
return 0; |
702 |
} |
703 |
else return 0; |
704 |
|
705 |
else if (xi > (albedo -= prdiff)) { |
706 |
/* Diffuse reflection */ |
707 |
photonRay(rayIn, &rayOut, PMAP_DIFFREFL, nd.mcolor); |
708 |
diffPhotonScatter(nd.pnorm, &rayOut); |
709 |
} |
710 |
|
711 |
else { |
712 |
/* Diffuse transmission */ |
713 |
FVECT bnorm; |
714 |
flipsurface(rayIn); |
715 |
bnorm [0] = -nd.pnorm [0]; |
716 |
bnorm [1] = -nd.pnorm [1]; |
717 |
bnorm [2] = -nd.pnorm [2]; |
718 |
|
719 |
photonRay(rayIn, &rayOut, PMAP_DIFFTRANS, nd.mcolor); |
720 |
diffPhotonScatter(bnorm, &rayOut); |
721 |
} |
722 |
|
723 |
tracePhoton(&rayOut); |
724 |
return 0; |
725 |
} |
726 |
|
727 |
|
728 |
static double mylog (double x) |
729 |
/* special log for extinction coefficients; cloned from dielectric.c */ |
730 |
{ |
731 |
if (x < 1e-40) |
732 |
return(-100.); |
733 |
|
734 |
if (x >= 1.) |
735 |
return(0.); |
736 |
|
737 |
return(log(x)); |
738 |
} |
739 |
|
740 |
|
741 |
static int dielectricPhotonScatter (OBJREC *mat, RAY *rayIn) |
742 |
/* Generate new photon ray for dielectric material and recurse */ |
743 |
{ |
744 |
double cos1, cos2, nratio, d1, d2, refl; |
745 |
COLOR ctrans, talb; |
746 |
FVECT dnorm; |
747 |
int hastexture, i; |
748 |
RAY rayOut; |
749 |
|
750 |
if (mat -> oargs.nfargs != (mat -> otype == MAT_DIELECTRIC ? 5 : 8)) |
751 |
objerror(mat, USER, "bad arguments"); |
752 |
|
753 |
/* get modifiers */ |
754 |
raytexture(rayIn, mat -> omod); |
755 |
|
756 |
if ((hastexture = DOT(rayIn -> pert, rayIn -> pert)) > FTINY * FTINY) |
757 |
/* Perturb normal */ |
758 |
cos1 = raynormal(dnorm, rayIn); |
759 |
else { |
760 |
VCOPY(dnorm, rayIn -> ron); |
761 |
cos1 = rayIn -> rod; |
762 |
} |
763 |
|
764 |
/* index of refraction */ |
765 |
nratio = mat -> otype == |
766 |
MAT_DIELECTRIC ? mat -> oargs.farg [3] + mat -> oargs.farg [4] / MLAMBDA |
767 |
: mat -> oargs.farg [3] / mat -> oargs.farg [7]; |
768 |
|
769 |
if (cos1 < 0) { |
770 |
/* inside */ |
771 |
hastexture = -hastexture; |
772 |
cos1 = -cos1; |
773 |
dnorm [0] = -dnorm [0]; |
774 |
dnorm [1] = -dnorm [1]; |
775 |
dnorm [2] = -dnorm [2]; |
776 |
setcolor(rayIn -> cext, |
777 |
-mylog(mat -> oargs.farg [0] * rayIn -> pcol [0]), |
778 |
-mylog(mat -> oargs.farg [1] * rayIn -> pcol [1]), |
779 |
-mylog(mat -> oargs.farg [2] * rayIn -> pcol [2])); |
780 |
setcolor(rayIn -> albedo, 0, 0, 0); |
781 |
rayIn -> gecc = 0; |
782 |
|
783 |
if (mat -> otype == MAT_INTERFACE) { |
784 |
setcolor(ctrans, |
785 |
-mylog(mat -> oargs.farg [4] * rayIn -> pcol [0]), |
786 |
-mylog(mat -> oargs.farg [5] * rayIn -> pcol [1]), |
787 |
-mylog(mat -> oargs.farg [6] * rayIn -> pcol [2])); |
788 |
setcolor(talb, 0, 0, 0); |
789 |
} |
790 |
else { |
791 |
copycolor(ctrans, cextinction); |
792 |
copycolor(talb, salbedo); |
793 |
} |
794 |
} |
795 |
|
796 |
else { |
797 |
/* outside */ |
798 |
nratio = 1.0 / nratio; |
799 |
setcolor(ctrans, |
800 |
-mylog(mat -> oargs.farg [0] * rayIn -> pcol [0]), |
801 |
-mylog(mat -> oargs.farg [1] * rayIn -> pcol [1]), |
802 |
-mylog(mat -> oargs.farg [2] * rayIn -> pcol [2])); |
803 |
setcolor(talb, 0, 0, 0); |
804 |
|
805 |
if (mat -> otype == MAT_INTERFACE) { |
806 |
setcolor(rayIn -> cext, |
807 |
-mylog(mat -> oargs.farg [4] * rayIn -> pcol [0]), |
808 |
-mylog(mat -> oargs.farg [5] * rayIn -> pcol [1]), |
809 |
-mylog(mat -> oargs.farg [6] * rayIn -> pcol [2])); |
810 |
setcolor(rayIn -> albedo, 0, 0, 0); |
811 |
rayIn -> gecc = 0; |
812 |
} |
813 |
} |
814 |
|
815 |
/* compute cos theta2 */ |
816 |
d2 = 1 - sqr(nratio) * (1 - sqr(cos1)); |
817 |
|
818 |
if (d2 < FTINY) { |
819 |
/* Total reflection */ |
820 |
refl = cos2 = 1.0; |
821 |
} |
822 |
else { |
823 |
/* Refraction, compute Fresnel's equations */ |
824 |
cos2 = sqrt(d2); |
825 |
d1 = cos1; |
826 |
d2 = nratio * cos2; |
827 |
d1 = (d1 - d2) / (d1 + d2); |
828 |
refl = sqr(d1); |
829 |
d1 = 1 / cos1; |
830 |
d2 = nratio / cos2; |
831 |
d1 = (d1 - d2) / (d1 + d2); |
832 |
refl += sqr(d1); |
833 |
refl *= 0.5; |
834 |
} |
835 |
|
836 |
if (pmapRandom(rouletteState) > refl) { |
837 |
/* Refraction */ |
838 |
photonRay(rayIn, &rayOut, PMAP_REFRACT, NULL); |
839 |
d1 = nratio * cos1 - cos2; |
840 |
|
841 |
for (i = 0; i < 3; i++) |
842 |
rayOut.rdir [i] = nratio * rayIn -> rdir [i] + d1 * dnorm [i]; |
843 |
|
844 |
if (hastexture && DOT(rayOut.rdir, rayIn -> ron) * hastexture >= -FTINY) { |
845 |
d1 *= hastexture; |
846 |
|
847 |
for (i = 0; i < 3; i++) |
848 |
rayOut.rdir [i] = nratio * rayIn -> rdir [i] + |
849 |
d1 * rayIn -> ron [i]; |
850 |
|
851 |
normalize(rayOut.rdir); |
852 |
} |
853 |
|
854 |
copycolor(rayOut.cext, ctrans); |
855 |
copycolor(rayOut.albedo, talb); |
856 |
} |
857 |
|
858 |
else { |
859 |
/* Reflection */ |
860 |
photonRay(rayIn, &rayOut, PMAP_SPECREFL, NULL); |
861 |
VSUM(rayOut.rdir, rayIn -> rdir, dnorm, 2 * cos1); |
862 |
|
863 |
if (hastexture && DOT(rayOut.rdir, rayIn -> ron) * hastexture <= FTINY) |
864 |
for (i = 0; i < 3; i++) |
865 |
rayOut.rdir [i] = rayIn -> rdir [i] + |
866 |
2 * rayIn -> rod * rayIn -> ron [i]; |
867 |
} |
868 |
|
869 |
/* Ray is modified by medium defined by cext and albedo in |
870 |
* photonParticipate() */ |
871 |
tracePhoton(&rayOut); |
872 |
|
873 |
return 0; |
874 |
} |
875 |
|
876 |
|
877 |
|
878 |
static int glassPhotonScatter (OBJREC *mat, RAY *rayIn) |
879 |
/* Generate new photon ray for glass material and recurse */ |
880 |
{ |
881 |
float albedo, xi, ptrans; |
882 |
COLOR mcolor, refl, trans; |
883 |
double pdot, cos2, d, r1e, r1m, rindex = 0.0; |
884 |
FVECT pnorm, pdir; |
885 |
int hastexture, i; |
886 |
RAY rayOut; |
887 |
|
888 |
/* check arguments */ |
889 |
if (mat -> oargs.nfargs == 3) |
890 |
rindex = RINDEX; |
891 |
else if (mat -> oargs.nfargs == 4) |
892 |
rindex = mat -> oargs.farg [3]; |
893 |
else objerror(mat, USER, "bad arguments"); |
894 |
|
895 |
copycolor(mcolor, mat -> oargs.farg); |
896 |
|
897 |
/* get modifiers */ |
898 |
raytexture(rayIn, mat -> omod); |
899 |
|
900 |
/* reorient if necessary */ |
901 |
if (rayIn -> rod < 0) |
902 |
flipsurface(rayIn); |
903 |
if ((hastexture = DOT(rayIn -> pert, rayIn -> pert)) > FTINY * FTINY) |
904 |
pdot = raynormal(pnorm, rayIn); |
905 |
else { |
906 |
VCOPY(pnorm, rayIn -> ron); |
907 |
pdot = rayIn -> rod; |
908 |
} |
909 |
|
910 |
/* Modify material color */ |
911 |
multcolor(mcolor, rayIn -> pcol); |
912 |
|
913 |
/* angular transmission */ |
914 |
cos2 = sqrt((1 - 1 / sqr(rindex)) + sqr(pdot / rindex)); |
915 |
setcolor(mcolor, pow(mcolor [0], 1 / cos2), pow(mcolor [1], 1 / cos2), |
916 |
pow(mcolor [2], 1 / cos2)); |
917 |
|
918 |
/* compute reflection */ |
919 |
r1e = (pdot - rindex * cos2) / (pdot + rindex * cos2); |
920 |
r1e *= r1e; |
921 |
r1m = (1 / pdot - rindex / cos2) / (1 / pdot + rindex / cos2); |
922 |
r1m *= r1m; |
923 |
|
924 |
for (i = 0; i < 3; i++) { |
925 |
double r1ed2, r1md2, d2; |
926 |
|
927 |
d = mcolor [i]; |
928 |
d2 = sqr(d); |
929 |
r1ed2 = sqr(r1e) * d2; |
930 |
r1md2 = sqr(r1m) * d2; |
931 |
|
932 |
/* compute transmittance */ |
933 |
trans [i] = 0.5 * d * |
934 |
(sqr(1 - r1e) / (1 - r1ed2) + sqr(1 - r1m) / (1 - r1md2)); |
935 |
|
936 |
/* compute reflectance */ |
937 |
refl [i] = 0.5 * (r1e * (1 + (1 - 2 * r1e) * d2) / (1 - r1ed2) + |
938 |
r1m * (1 + (1 - 2 * r1m) * d2) / (1 - r1md2)); |
939 |
} |
940 |
|
941 |
/* Set up probabilities */ |
942 |
ptrans = colorAvg(trans); |
943 |
albedo = colorAvg(refl) + ptrans; |
944 |
xi = pmapRandom(rouletteState); |
945 |
|
946 |
|
947 |
if (xi > albedo) |
948 |
/* Absorbed */ |
949 |
return 0; |
950 |
|
951 |
if (xi > (albedo -= ptrans)) { |
952 |
/* Transmitted */ |
953 |
|
954 |
if (hastexture) { |
955 |
/* perturb direction */ |
956 |
VSUM(pdir, rayIn -> rdir, rayIn -> pert, 2 * (1 - rindex)); |
957 |
|
958 |
if (normalize(pdir) == 0) { |
959 |
objerror(mat, WARNING, "bad perturbation"); |
960 |
VCOPY(pdir, rayIn -> rdir); |
961 |
} |
962 |
} |
963 |
else VCOPY(pdir, rayIn -> rdir); |
964 |
|
965 |
VCOPY(rayOut.rdir, pdir); |
966 |
photonRay(rayIn, &rayOut, PMAP_SPECTRANS, mcolor); |
967 |
} |
968 |
|
969 |
else { |
970 |
/* reflected ray */ |
971 |
VSUM(rayOut.rdir, rayIn -> rdir, pnorm, 2 * pdot); |
972 |
photonRay(rayIn, &rayOut, PMAP_SPECREFL, mcolor); |
973 |
} |
974 |
|
975 |
tracePhoton(&rayOut); |
976 |
return 0; |
977 |
} |
978 |
|
979 |
|
980 |
|
981 |
static int aliasPhotonScatter (OBJREC *mat, RAY *rayIn) |
982 |
/* Transfer photon scattering to alias target */ |
983 |
{ |
984 |
OBJECT aliasObj; |
985 |
OBJREC aliasRec; |
986 |
|
987 |
/* Straight replacement? */ |
988 |
if (!mat -> oargs.nsargs) { |
989 |
mat = objptr(mat -> omod); |
990 |
photonScatter [mat -> otype] (mat, rayIn); |
991 |
|
992 |
return 0; |
993 |
} |
994 |
|
995 |
/* Else replace alias */ |
996 |
if (mat -> oargs.nsargs != 1) |
997 |
objerror(mat, INTERNAL, "bad # string arguments"); |
998 |
|
999 |
aliasObj = lastmod(objndx(mat), mat -> oargs.sarg [0]); |
1000 |
|
1001 |
if (aliasObj < 0) |
1002 |
objerror(mat, USER, "bad reference"); |
1003 |
|
1004 |
memcpy(&aliasRec, objptr(aliasObj), sizeof(OBJREC)); |
1005 |
|
1006 |
/* Substitute modifier */ |
1007 |
aliasRec.omod = mat -> omod; |
1008 |
|
1009 |
/* Replacement scattering routine */ |
1010 |
photonScatter [aliasRec.otype] (&aliasRec, rayIn); |
1011 |
return 0; |
1012 |
} |
1013 |
|
1014 |
|
1015 |
|
1016 |
static int clipPhotonScatter (OBJREC *mat, RAY *rayIn) |
1017 |
/* Generate new photon ray for antimatter material and recurse */ |
1018 |
{ |
1019 |
OBJECT obj = objndx(mat), mod, cset [MAXSET + 1], *modset; |
1020 |
int entering, inside = 0, i; |
1021 |
const RAY *rp; |
1022 |
RAY rayOut; |
1023 |
|
1024 |
if ((modset = (OBJECT*)mat -> os) == NULL) { |
1025 |
if (mat -> oargs.nsargs < 1 || mat -> oargs.nsargs > MAXSET) |
1026 |
objerror(mat, USER, "bad # arguments"); |
1027 |
|
1028 |
modset = (OBJECT*)malloc((mat -> oargs.nsargs + 1) * sizeof(OBJECT)); |
1029 |
|
1030 |
if (modset == NULL) |
1031 |
error(SYSTEM, "out of memory in clipPhotonScatter"); |
1032 |
modset [0] = 0; |
1033 |
|
1034 |
for (i = 0; i < mat -> oargs.nsargs; i++) { |
1035 |
if (!strcmp(mat -> oargs.sarg [i], VOIDID)) |
1036 |
continue; |
1037 |
|
1038 |
if ((mod = lastmod(obj, mat -> oargs.sarg [i])) == OVOID) { |
1039 |
sprintf(errmsg, "unknown modifier \"%s\"", mat -> oargs.sarg [i]); |
1040 |
objerror(mat, WARNING, errmsg); |
1041 |
continue; |
1042 |
} |
1043 |
|
1044 |
if (inset(modset, mod)) { |
1045 |
objerror(mat, WARNING, "duplicate modifier"); |
1046 |
continue; |
1047 |
} |
1048 |
|
1049 |
insertelem(modset, mod); |
1050 |
} |
1051 |
|
1052 |
mat -> os = (char*)modset; |
1053 |
} |
1054 |
|
1055 |
if (rayIn -> clipset != NULL) |
1056 |
setcopy(cset, rayIn -> clipset); |
1057 |
else cset [0] = 0; |
1058 |
|
1059 |
entering = rayIn -> rod > 0; |
1060 |
|
1061 |
/* Store photon incident from front if material defined as sensor */ |
1062 |
if (entering && inset(photonSensorSet, obj)) |
1063 |
addPhotons(rayIn); |
1064 |
|
1065 |
for (i = modset [0]; i > 0; i--) { |
1066 |
if (entering) { |
1067 |
if (!inset(cset, modset [i])) { |
1068 |
if (cset [0] >= MAXSET) |
1069 |
error(INTERNAL, "set overflow in clipPhotonScatter"); |
1070 |
insertelem(cset, modset [i]); |
1071 |
} |
1072 |
} |
1073 |
else if (inset(cset, modset [i])) |
1074 |
deletelem(cset, modset [i]); |
1075 |
} |
1076 |
|
1077 |
rayIn -> newcset = cset; |
1078 |
|
1079 |
if (strcmp(mat -> oargs.sarg [0], VOIDID)) { |
1080 |
for (rp = rayIn; rp -> parent != NULL; rp = rp -> parent) { |
1081 |
if ( !(rp -> rtype & RAYREFL) && rp->parent->ro != NULL && |
1082 |
inset(modset, rp -> parent -> ro -> omod)) { |
1083 |
|
1084 |
if (rp -> parent -> rod > 0) |
1085 |
inside++; |
1086 |
else inside--; |
1087 |
} |
1088 |
} |
1089 |
|
1090 |
if (inside > 0) { |
1091 |
flipsurface(rayIn); |
1092 |
mat = objptr(lastmod(obj, mat -> oargs.sarg [0])); |
1093 |
photonScatter [mat -> otype] (mat, rayIn); |
1094 |
return 0; |
1095 |
} |
1096 |
} |
1097 |
|
1098 |
/* Else transfer ray */ |
1099 |
photonRay(rayIn, &rayOut, PMAP_XFER, NULL); |
1100 |
tracePhoton(&rayOut); |
1101 |
|
1102 |
return 0; |
1103 |
} |
1104 |
|
1105 |
|
1106 |
|
1107 |
static int mirrorPhotonScatter (OBJREC *mat, RAY *rayIn) |
1108 |
/* Generate new photon ray for mirror material and recurse */ |
1109 |
{ |
1110 |
RAY rayOut; |
1111 |
int rpure = 1, i; |
1112 |
FVECT pnorm; |
1113 |
double pdot; |
1114 |
float albedo; |
1115 |
COLOR mcolor; |
1116 |
|
1117 |
/* check arguments */ |
1118 |
if (mat -> oargs.nfargs != 3 || mat -> oargs.nsargs > 1) |
1119 |
objerror(mat, USER, "bad number of arguments"); |
1120 |
|
1121 |
/* back is black */ |
1122 |
if (rayIn -> rod < 0) |
1123 |
return 0; |
1124 |
|
1125 |
/* get modifiers */ |
1126 |
raytexture(rayIn, mat -> omod); |
1127 |
|
1128 |
/* assign material color */ |
1129 |
copycolor(mcolor, mat -> oargs.farg); |
1130 |
multcolor(mcolor, rayIn -> pcol); |
1131 |
|
1132 |
/* Set up probabilities */ |
1133 |
albedo = colorAvg(mcolor); |
1134 |
|
1135 |
if (pmapRandom(rouletteState) > albedo) |
1136 |
/* Absorbed */ |
1137 |
return 0; |
1138 |
|
1139 |
/* compute reflected ray */ |
1140 |
photonRay(rayIn, &rayOut, PMAP_SPECREFL, mcolor); |
1141 |
|
1142 |
if (DOT(rayIn -> pert, rayIn -> pert) > sqr(FTINY)) { |
1143 |
/* use textures */ |
1144 |
pdot = raynormal(pnorm, rayIn); |
1145 |
|
1146 |
for (i = 0; i < 3; i++) |
1147 |
rayOut.rdir [i] = rayIn -> rdir [i] + 2 * pdot * pnorm [i]; |
1148 |
|
1149 |
rpure = 0; |
1150 |
} |
1151 |
|
1152 |
/* Check for penetration */ |
1153 |
if (rpure || DOT(rayOut.rdir, rayIn -> ron) <= FTINY) |
1154 |
for (i = 0; i < 3; i++) |
1155 |
rayOut.rdir [i] = rayIn -> rdir [i] + |
1156 |
2 * rayIn -> rod * rayIn -> ron [i]; |
1157 |
|
1158 |
tracePhoton(&rayOut); |
1159 |
return 0; |
1160 |
} |
1161 |
|
1162 |
|
1163 |
|
1164 |
static int mistPhotonScatter (OBJREC *mat, RAY *rayIn) |
1165 |
/* Generate new photon ray within mist and recurse */ |
1166 |
{ |
1167 |
COLOR mext; |
1168 |
RREAL re, ge, be; |
1169 |
RAY rayOut; |
1170 |
|
1171 |
/* check arguments */ |
1172 |
if (mat -> oargs.nfargs > 7) |
1173 |
objerror(mat, USER, "bad arguments"); |
1174 |
|
1175 |
if (mat -> oargs.nfargs > 2) { |
1176 |
/* compute extinction */ |
1177 |
copycolor(mext, mat -> oargs.farg); |
1178 |
/* get modifiers */ |
1179 |
raytexture(rayIn, mat -> omod); |
1180 |
multcolor(mext, rayIn -> pcol); |
1181 |
} |
1182 |
else setcolor(mext, 0, 0, 0); |
1183 |
|
1184 |
photonRay(rayIn, &rayOut, PMAP_XFER, NULL); |
1185 |
|
1186 |
if (rayIn -> rod > 0) { |
1187 |
/* entering ray */ |
1188 |
addcolor(rayOut.cext, mext); |
1189 |
|
1190 |
if (mat -> oargs.nfargs > 5) |
1191 |
copycolor(rayOut.albedo, mat -> oargs.farg + 3); |
1192 |
if (mat -> oargs.nfargs > 6) |
1193 |
rayOut.gecc = mat -> oargs.farg [6]; |
1194 |
} |
1195 |
|
1196 |
else { |
1197 |
/* leaving ray */ |
1198 |
re = max(rayIn -> cext [0] - mext [0], cextinction [0]); |
1199 |
ge = max(rayIn -> cext [1] - mext [1], cextinction [1]); |
1200 |
be = max(rayIn -> cext [2] - mext [2], cextinction [2]); |
1201 |
setcolor(rayOut.cext, re, ge, be); |
1202 |
|
1203 |
if (mat -> oargs.nfargs > 5) |
1204 |
copycolor(rayOut.albedo, salbedo); |
1205 |
if (mat -> oargs.nfargs > 6) |
1206 |
rayOut.gecc = seccg; |
1207 |
} |
1208 |
|
1209 |
tracePhoton(&rayOut); |
1210 |
|
1211 |
return 0; |
1212 |
} |
1213 |
|
1214 |
|
1215 |
|
1216 |
static int mx_dataPhotonScatter (OBJREC *mat, RAY *rayIn) |
1217 |
/* Pass photon on to materials selected by mixture data */ |
1218 |
{ |
1219 |
OBJECT obj; |
1220 |
double coef, pt [MAXDIM]; |
1221 |
DATARRAY *dp; |
1222 |
OBJECT mod [2]; |
1223 |
MFUNC *mf; |
1224 |
int i; |
1225 |
|
1226 |
if (mat -> oargs.nsargs < 6) |
1227 |
objerror(mat, USER, "bad # arguments"); |
1228 |
|
1229 |
obj = objndx(mat); |
1230 |
|
1231 |
for (i = 0; i < 2; i++) |
1232 |
if (!strcmp(mat -> oargs.sarg [i], VOIDID)) |
1233 |
mod [i] = OVOID; |
1234 |
else if ((mod [i] = lastmod(obj, mat -> oargs.sarg [i])) == OVOID) { |
1235 |
sprintf(errmsg, "undefined modifier \"%s\"", mat -> oargs.sarg [i]); |
1236 |
objerror(mat, USER, errmsg); |
1237 |
} |
1238 |
|
1239 |
dp = getdata(mat -> oargs.sarg [3]); |
1240 |
i = (1 << dp -> nd) - 1; |
1241 |
mf = getfunc(mat, 4, i << 5, 0); |
1242 |
setfunc(mat, rayIn); |
1243 |
errno = 0; |
1244 |
|
1245 |
for (i = 0; i < dp -> nd; i++) { |
1246 |
pt [i] = evalue(mf -> ep [i]); |
1247 |
|
1248 |
if (errno) { |
1249 |
objerror(mat, WARNING, "compute error"); |
1250 |
return 0; |
1251 |
} |
1252 |
} |
1253 |
|
1254 |
coef = datavalue(dp, pt); |
1255 |
errno = 0; |
1256 |
coef = funvalue(mat -> oargs.sarg [2], 1, &coef); |
1257 |
|
1258 |
if (errno) |
1259 |
objerror(mat, WARNING, "compute error"); |
1260 |
else { |
1261 |
mat = objptr(mod [pmapRandom(rouletteState) < coef ? 0 : 1]); |
1262 |
photonScatter [mat -> otype] (mat, rayIn); |
1263 |
} |
1264 |
|
1265 |
return 0; |
1266 |
} |
1267 |
|
1268 |
|
1269 |
|
1270 |
static int mx_pdataPhotonScatter (OBJREC *mat, RAY *rayIn) |
1271 |
/* Pass photon on to materials selected by mixture picture */ |
1272 |
{ |
1273 |
OBJECT obj; |
1274 |
double col [3], coef, pt [MAXDIM]; |
1275 |
DATARRAY *dp; |
1276 |
OBJECT mod [2]; |
1277 |
MFUNC *mf; |
1278 |
int i; |
1279 |
|
1280 |
if (mat -> oargs.nsargs < 7) |
1281 |
objerror(mat, USER, "bad # arguments"); |
1282 |
|
1283 |
obj = objndx(mat); |
1284 |
|
1285 |
for (i = 0; i < 2; i++) |
1286 |
if (!strcmp(mat -> oargs.sarg [i], VOIDID)) |
1287 |
mod [i] = OVOID; |
1288 |
else if ((mod [i] = lastmod(obj, mat -> oargs.sarg [i])) == OVOID) { |
1289 |
sprintf(errmsg, "undefined modifier \"%s\"", mat -> oargs.sarg [i]); |
1290 |
objerror(mat, USER, errmsg); |
1291 |
} |
1292 |
|
1293 |
dp = getpict(mat -> oargs.sarg [3]); |
1294 |
mf = getfunc(mat, 4, 0x3 << 5, 0); |
1295 |
setfunc(mat, rayIn); |
1296 |
errno = 0; |
1297 |
pt [1] = evalue(mf -> ep [0]); |
1298 |
pt [0] = evalue(mf -> ep [1]); |
1299 |
|
1300 |
if (errno) { |
1301 |
objerror(mat, WARNING, "compute error"); |
1302 |
return 0; |
1303 |
} |
1304 |
|
1305 |
for (i = 0; i < 3; i++) |
1306 |
col [i] = datavalue(dp + i, pt); |
1307 |
|
1308 |
errno = 0; |
1309 |
coef = funvalue(mat -> oargs.sarg [2], 3, col); |
1310 |
|
1311 |
if (errno) |
1312 |
objerror(mat, WARNING, "compute error"); |
1313 |
else { |
1314 |
mat = objptr(mod [pmapRandom(rouletteState) < coef ? 0 : 1]); |
1315 |
photonScatter [mat -> otype] (mat, rayIn); |
1316 |
} |
1317 |
|
1318 |
return 0; |
1319 |
} |
1320 |
|
1321 |
|
1322 |
|
1323 |
static int mx_funcPhotonScatter (OBJREC *mat, RAY *rayIn) |
1324 |
/* Pass photon on to materials selected by mixture function */ |
1325 |
{ |
1326 |
OBJECT obj, mod [2]; |
1327 |
int i; |
1328 |
double coef; |
1329 |
MFUNC *mf; |
1330 |
|
1331 |
if (mat -> oargs.nsargs < 4) |
1332 |
objerror(mat, USER, "bad # arguments"); |
1333 |
|
1334 |
obj = objndx(mat); |
1335 |
|
1336 |
for (i = 0; i < 2; i++) |
1337 |
if (!strcmp(mat -> oargs.sarg [i], VOIDID)) |
1338 |
mod [i] = OVOID; |
1339 |
else if ((mod [i] = lastmod(obj, mat -> oargs.sarg [i])) == OVOID) { |
1340 |
sprintf(errmsg, "undefined modifier \"%s\"", mat -> oargs.sarg [i]); |
1341 |
objerror(mat, USER, errmsg); |
1342 |
} |
1343 |
|
1344 |
mf = getfunc(mat, 3, 0x4, 0); |
1345 |
setfunc(mat, rayIn); |
1346 |
errno = 0; |
1347 |
|
1348 |
/* bound coefficient */ |
1349 |
coef = min(1, max(0, evalue(mf -> ep [0]))); |
1350 |
|
1351 |
if (errno) |
1352 |
objerror(mat, WARNING, "compute error"); |
1353 |
else { |
1354 |
mat = objptr(mod [pmapRandom(rouletteState) < coef ? 0 : 1]); |
1355 |
photonScatter [mat -> otype] (mat, rayIn); |
1356 |
} |
1357 |
|
1358 |
return 0; |
1359 |
} |
1360 |
|
1361 |
|
1362 |
|
1363 |
static int pattexPhotonScatter (OBJREC *mat, RAY *rayIn) |
1364 |
/* Generate new photon ray for pattern or texture modifier and recurse. |
1365 |
This code is brought to you by Henkel! :^) */ |
1366 |
{ |
1367 |
RAY rayOut; |
1368 |
|
1369 |
/* Get pattern */ |
1370 |
ofun [mat -> otype].funp(mat, rayIn); |
1371 |
if (mat -> omod != OVOID) { |
1372 |
/* Scatter using modifier (if any) */ |
1373 |
mat = objptr(mat -> omod); |
1374 |
photonScatter [mat -> otype] (mat, rayIn); |
1375 |
} |
1376 |
else { |
1377 |
/* Transfer ray if no modifier */ |
1378 |
photonRay(rayIn, &rayOut, PMAP_XFER, NULL); |
1379 |
tracePhoton(&rayOut); |
1380 |
} |
1381 |
|
1382 |
return 0; |
1383 |
} |
1384 |
|
1385 |
|
1386 |
|
1387 |
#if 0 |
1388 |
static int bsdfPhotonScatter (OBJREC *mat, RAY *rayIn) |
1389 |
/* Generate new photon ray for BSDF modifier and recurse. */ |
1390 |
{ |
1391 |
int hitFront; |
1392 |
SDError err; |
1393 |
FVECT upvec; |
1394 |
MFUNC *mf; |
1395 |
BSDFDAT nd; |
1396 |
RAY rayOut; |
1397 |
|
1398 |
/* Following code adapted from m_bsdf() */ |
1399 |
/* Check arguments */ |
1400 |
if (mat -> oargs.nsargs < 6 || mat -> oargs.nfargs > 9 || |
1401 |
mat -> oargs.nfargs % 3) |
1402 |
objerror(mat, USER, "bad # arguments"); |
1403 |
|
1404 |
hitFront = (rayIn -> rod > 0); |
1405 |
|
1406 |
/* Load cal file */ |
1407 |
mf = getfunc(mat, 5, 0x1d, 1); |
1408 |
|
1409 |
/* Get thickness */ |
1410 |
nd.thick = evalue(mf -> ep [0]); |
1411 |
if ((-FTINY <= nd.thick) & (nd.thick <= FTINY)) |
1412 |
nd.thick = .0; |
1413 |
|
1414 |
if (nd.thick != .0 || (!hitFront && !backvis)) { |
1415 |
/* Proxy geometry present, so use it instead and transfer ray */ |
1416 |
photonRay(rayIn, &rayOut, PMAP_XFER, NULL); |
1417 |
tracePhoton(&rayOut); |
1418 |
|
1419 |
return 0; |
1420 |
} |
1421 |
|
1422 |
/* Get BSDF data */ |
1423 |
nd.sd = loadBSDF(mat -> oargs.sarg [1]); |
1424 |
|
1425 |
/* Diffuse reflectance */ |
1426 |
if (hitFront) { |
1427 |
if (mat -> oargs.nfargs < 3) |
1428 |
setcolor(nd.rdiff, .0, .0, .0); |
1429 |
else setcolor(nd.rdiff, mat -> oargs.farg [0], mat -> oargs.farg [1], |
1430 |
mat -> oargs.farg [2]); |
1431 |
} |
1432 |
else if (mat -> oargs.nfargs < 6) { |
1433 |
/* Check for absorbing backside */ |
1434 |
if (!backvis && !nd.sd -> rb && !nd.sd -> tf) { |
1435 |
SDfreeCache(nd.sd); |
1436 |
return 0; |
1437 |
} |
1438 |
|
1439 |
setcolor(nd.rdiff, .0, .0, .0); |
1440 |
} |
1441 |
else setcolor(nd.rdiff, mat -> oargs.farg [3], mat -> oargs.farg [4], |
1442 |
mat -> oargs.farg [5]); |
1443 |
|
1444 |
/* Diffuse transmittance */ |
1445 |
if (mat -> oargs.nfargs < 9) |
1446 |
setcolor(nd.tdiff, .0, .0, .0); |
1447 |
else setcolor(nd.tdiff, mat -> oargs.farg [6], mat -> oargs.farg [7], |
1448 |
mat -> oargs.farg [8]); |
1449 |
|
1450 |
nd.mp = mat; |
1451 |
nd.pr = rayIn; |
1452 |
|
1453 |
/* Get modifiers */ |
1454 |
raytexture(rayIn, mat -> omod); |
1455 |
|
1456 |
/* Modify diffuse values */ |
1457 |
multcolor(nd.rdiff, rayIn -> pcol); |
1458 |
multcolor(nd.tdiff, rayIn -> pcol); |
1459 |
|
1460 |
/* Get up vector & xform to world coords */ |
1461 |
upvec [0] = evalue(mf -> ep [1]); |
1462 |
upvec [1] = evalue(mf -> ep [2]); |
1463 |
upvec [2] = evalue(mf -> ep [3]); |
1464 |
|
1465 |
if (mf -> fxp != &unitxf) { |
1466 |
multv3(upvec, upvec, mf -> fxp -> xfm); |
1467 |
nd.thick *= mf -> fxp -> sca; |
1468 |
} |
1469 |
|
1470 |
if (rayIn -> rox) { |
1471 |
multv3(upvec, upvec, rayIn -> rox -> f.xfm); |
1472 |
nd.thick *= rayIn -> rox -> f.sca; |
1473 |
} |
1474 |
|
1475 |
/* Perturb normal */ |
1476 |
raynormal(nd.pnorm, rayIn); |
1477 |
|
1478 |
/* Xform incident dir to local BSDF coords */ |
1479 |
err = SDcompXform(nd.toloc, nd.pnorm, upvec); |
1480 |
|
1481 |
if (!err) { |
1482 |
nd.vray [0] = -rayIn -> rdir [0]; |
1483 |
nd.vray [1] = -rayIn -> rdir [1]; |
1484 |
nd.vray [2] = -rayIn -> rdir [2]; |
1485 |
err = SDmapDir(nd.vray, nd.toloc, nd.vray); |
1486 |
} |
1487 |
|
1488 |
if (!err) |
1489 |
err = SDinvXform(nd.fromloc, nd.toloc); |
1490 |
|
1491 |
if (err) { |
1492 |
objerror(mat, WARNING, "Illegal orientation vector"); |
1493 |
return 0; |
1494 |
} |
1495 |
|
1496 |
/* Determine BSDF resolution */ |
1497 |
err = SDsizeBSDF(nd.sr_vpsa, nd.vray, NULL, SDqueryMin + SDqueryMax, nd.sd); |
1498 |
|
1499 |
if (err) |
1500 |
objerror(mat, USER, transSDError(err)); |
1501 |
|
1502 |
nd.sr_vpsa [0] = sqrt(nd.sr_vpsa [0]); |
1503 |
nd.sr_vpsa [1] = sqrt(nd.sr_vpsa [1]); |
1504 |
|
1505 |
/* Orient perturbed normal towards incident side */ |
1506 |
if (!hitFront) { |
1507 |
nd.pnorm [0] = -nd.pnorm [0]; |
1508 |
nd.pnorm [1] = -nd.pnorm [1]; |
1509 |
nd.pnorm [2] = -nd.pnorm [2]; |
1510 |
} |
1511 |
|
1512 |
/* Following code adapted from SDsampBSDF() */ |
1513 |
{ |
1514 |
SDSpectralDF *rdf, *tdf; |
1515 |
SDValue bsdfVal; |
1516 |
double xi, rhoDiff = 0; |
1517 |
float coef [SDmaxCh]; |
1518 |
int i, j, n, nr; |
1519 |
SDComponent *sdc; |
1520 |
const SDCDst **cdarr = NULL; |
1521 |
|
1522 |
/* Get diffuse albedo (?) */ |
1523 |
if (hitFront) { |
1524 |
bsdfVal = nd.sd -> rLambFront; |
1525 |
rdf = nd.sd -> rf; |
1526 |
tdf = nd.sd -> tf ? nd.sd -> tf : nd.sd -> tb; |
1527 |
} |
1528 |
else { |
1529 |
bsdfVal = nd.sd -> rLambBack; |
1530 |
rdf = nd.sd -> rb; |
1531 |
tdf = nd.sd -> tb ? nd.sd -> tb : nd.sd -> tf; |
1532 |
} |
1533 |
|
1534 |
rhoDiff = bsdfVal.cieY; |
1535 |
bsdfVal.cieY += nd.sd -> tLamb.cieY; |
1536 |
|
1537 |
/* Allocate non-diffuse sampling */ |
1538 |
i = nr = rdf ? rdf -> ncomp : 0; |
1539 |
j = tdf ? tdf -> ncomp : 0; |
1540 |
n = i + j; |
1541 |
|
1542 |
if (n > 0 && !(cdarr = (const SDCDst**)malloc(n * sizeof(SDCDst*)))) |
1543 |
objerror(mat, USER, transSDError(SDEmemory)); |
1544 |
|
1545 |
while (j-- > 0) { |
1546 |
/* Sum up non-diffuse transmittance */ |
1547 |
cdarr [i + j] = (*tdf -> comp [j].func -> getCDist)(nd.vray, &tdf -> comp [j]); |
1548 |
|
1549 |
if (!cdarr [i + j]) |
1550 |
cdarr [i + j] = &SDemptyCD; |
1551 |
else bsdfVal.cieY += cdarr [i + j] -> cTotal; |
1552 |
} |
1553 |
|
1554 |
while (i-- > 0) { |
1555 |
/* Sum up non-diffuse reflectance */ |
1556 |
cdarr [i] = (*rdf -> comp [i].func -> getCDist)(nd.vray, &rdf -> comp [i]); |
1557 |
|
1558 |
if (!cdarr [i]) |
1559 |
cdarr [i] = &SDemptyCD; |
1560 |
else bsdfVal.cieY += cdarr [i] -> cTotal; |
1561 |
} |
1562 |
|
1563 |
if (bsdfVal.cieY <= FTINY) { |
1564 |
/* Don't bother sampling, just absorb photon */ |
1565 |
if (cdarr) |
1566 |
free(cdarr); |
1567 |
return 0; |
1568 |
} |
1569 |
|
1570 |
/* Insert direct and indirect photon hits if diffuse component */ |
1571 |
if (rhoDiff > FTINY || nd.sd -> tLamb.cieY > FTINY) |
1572 |
addPhotons(rayIn); |
1573 |
|
1574 |
xi = pmapRandom(rouletteState); |
1575 |
|
1576 |
if ((xi -= rhoDiff) <= 0) { |
1577 |
/* Diffuse reflection */ |
1578 |
photonRay(rayIn, &rayOut, PMAP_DIFFREFL, nd.rdiff); |
1579 |
diffPhotonScatter(nd.pnorm, &rayOut); |
1580 |
} |
1581 |
else if ((xi -= nd.sd -> tLamb.cieY) <= 0) { |
1582 |
/* Diffuse transmission */ |
1583 |
flipsurface(rayIn); |
1584 |
photonRay(rayIn, &rayOut, PMAP_DIFFTRANS, nd.tdiff); |
1585 |
bsdfVal.spec = nd.sd -> tLamb.spec; |
1586 |
diffPhotonScatter(nd.pnorm, &rayOut); |
1587 |
} |
1588 |
else { |
1589 |
int rayOutType; |
1590 |
COLOR bsdfRGB; |
1591 |
|
1592 |
/* Non-diffuse CDF inversion (?) */ |
1593 |
for (i = 0; i < n && (xi -= cdarr [i] -> cTotal) > 0; i++); |
1594 |
|
1595 |
if (i >= n) { |
1596 |
/* Absorbed -- photon went Deer Hunter */ |
1597 |
if (cdarr) |
1598 |
free(cdarr); |
1599 |
return 0; |
1600 |
} |
1601 |
|
1602 |
if (i < nr) { |
1603 |
/* Non-diffuse reflection */ |
1604 |
sdc = &rdf -> comp [i]; |
1605 |
rayOutType = PMAP_SPECREFL; |
1606 |
} |
1607 |
else { |
1608 |
/* Non-diffuse transmission */ |
1609 |
sdc = &tdf -> comp [i - nr]; |
1610 |
rayOutType = PMAP_SPECTRANS; |
1611 |
} |
1612 |
|
1613 |
/* Generate non-diff sample dir */ |
1614 |
VCOPY(rayOut.rdir, nd.vray); |
1615 |
err = (*sdc -> func -> sampCDist) |
1616 |
(rayOut.rdir, pmapRandom(scatterState), cdarr [i]); |
1617 |
if (err) |
1618 |
objerror(mat, USER, transSDError(SDEinternal)); |
1619 |
|
1620 |
/* Get colour */ |
1621 |
j = (*sdc -> func -> getBSDFs)(coef, rayOut.rdir, nd.vray, sdc); |
1622 |
|
1623 |
if (j <= 0) { |
1624 |
sprintf(SDerrorDetail, "BSDF \"%s\" sampling value error", |
1625 |
nd.sd -> name); |
1626 |
objerror(mat, USER, transSDError(SDEinternal)); |
1627 |
} |
1628 |
|
1629 |
bsdfVal.spec = sdc -> cspec [0]; |
1630 |
rhoDiff = coef [0]; |
1631 |
|
1632 |
while (--j) { |
1633 |
c_cmix(&bsdfVal.spec, rhoDiff, &bsdfVal.spec, coef [j], |
1634 |
&sdc -> cspec [j]); |
1635 |
rhoDiff += coef [j]; |
1636 |
} |
1637 |
|
1638 |
/* ? */ |
1639 |
c_ccvt(&bsdfVal.spec, C_CSXY + C_CSSPEC); |
1640 |
ccy2rgb(&bsdfVal.spec, bsdfVal.cieY, bsdfRGB); |
1641 |
|
1642 |
/* Xform outgoing dir to world coords */ |
1643 |
if ((err = SDmapDir(rayOut.rdir, nd.fromloc, rayOut.rdir))) { |
1644 |
objerror(mat, USER, transSDError(err)); |
1645 |
return 0; |
1646 |
} |
1647 |
|
1648 |
photonRay(rayIn, &rayOut, rayOutType, bsdfRGB); |
1649 |
} |
1650 |
|
1651 |
if (cdarr) |
1652 |
free(cdarr); |
1653 |
} |
1654 |
|
1655 |
/* Clean up BSDF */ |
1656 |
SDfreeCache(nd.sd); |
1657 |
|
1658 |
tracePhoton(&rayOut); |
1659 |
return 0; |
1660 |
} |
1661 |
#else |
1662 |
|
1663 |
/* |
1664 |
The following code is |
1665 |
(c) Lucerne University of Applied Sciences and Arts, |
1666 |
supported by the Swiss National Science Foundation (SNSF, #147053) |
1667 |
*/ |
1668 |
|
1669 |
static int bsdfPhotonScatter (OBJREC *mat, RAY *rayIn) |
1670 |
/* Generate new photon ray for BSDF modifier and recurse. */ |
1671 |
{ |
1672 |
int hitFront; |
1673 |
SDError err; |
1674 |
SDValue bsdfVal; |
1675 |
FVECT upvec; |
1676 |
MFUNC *mf; |
1677 |
BSDFDAT nd; |
1678 |
RAY rayOut; |
1679 |
COLOR bsdfRGB; |
1680 |
double prDiff, ptDiff, prDiffSD, ptDiffSD, prSpecSD, ptSpecSD, |
1681 |
albedo, xi, xi2; |
1682 |
const double patAlb = colorAvg(rayIn -> pcol); |
1683 |
|
1684 |
/* Following code adapted from m_bsdf() */ |
1685 |
/* Check arguments */ |
1686 |
if (mat -> oargs.nsargs < 6 || mat -> oargs.nfargs > 9 || |
1687 |
mat -> oargs.nfargs % 3) |
1688 |
objerror(mat, USER, "bad # arguments"); |
1689 |
|
1690 |
hitFront = (rayIn -> rod > 0); |
1691 |
|
1692 |
/* Load cal file */ |
1693 |
mf = getfunc(mat, 5, 0x1d, 1); |
1694 |
|
1695 |
/* Get thickness */ |
1696 |
nd.thick = evalue(mf -> ep [0]); |
1697 |
if ((-FTINY <= nd.thick) & (nd.thick <= FTINY)) |
1698 |
nd.thick = .0; |
1699 |
|
1700 |
if (nd.thick != .0 || (!hitFront && !backvis)) { |
1701 |
/* Proxy geometry present, so use it instead and transfer ray */ |
1702 |
photonRay(rayIn, &rayOut, PMAP_XFER, NULL); |
1703 |
tracePhoton(&rayOut); |
1704 |
|
1705 |
return 0; |
1706 |
} |
1707 |
|
1708 |
/* Get BSDF data */ |
1709 |
nd.sd = loadBSDF(mat -> oargs.sarg [1]); |
1710 |
|
1711 |
/* Extra diffuse reflectance from material def */ |
1712 |
if (hitFront) { |
1713 |
if (mat -> oargs.nfargs < 3) |
1714 |
setcolor(nd.rdiff, .0, .0, .0); |
1715 |
else setcolor(nd.rdiff, mat -> oargs.farg [0], mat -> oargs.farg [1], |
1716 |
mat -> oargs.farg [2]); |
1717 |
} |
1718 |
else if (mat -> oargs.nfargs < 6) { |
1719 |
/* Check for absorbing backside */ |
1720 |
if (!backvis && !nd.sd -> rb && !nd.sd -> tf) { |
1721 |
SDfreeCache(nd.sd); |
1722 |
return 0; |
1723 |
} |
1724 |
|
1725 |
setcolor(nd.rdiff, .0, .0, .0); |
1726 |
} |
1727 |
else setcolor(nd.rdiff, mat -> oargs.farg [3], mat -> oargs.farg [4], |
1728 |
mat -> oargs.farg [5]); |
1729 |
|
1730 |
/* Extra diffuse transmittance from material def */ |
1731 |
if (mat -> oargs.nfargs < 9) |
1732 |
setcolor(nd.tdiff, .0, .0, .0); |
1733 |
else setcolor(nd.tdiff, mat -> oargs.farg [6], mat -> oargs.farg [7], |
1734 |
mat -> oargs.farg [8]); |
1735 |
|
1736 |
nd.mp = mat; |
1737 |
nd.pr = rayIn; |
1738 |
|
1739 |
/* Get modifiers */ |
1740 |
raytexture(rayIn, mat -> omod); |
1741 |
|
1742 |
/* Modify diffuse values */ |
1743 |
multcolor(nd.rdiff, rayIn -> pcol); |
1744 |
multcolor(nd.tdiff, rayIn -> pcol); |
1745 |
|
1746 |
/* Get up vector & xform to world coords */ |
1747 |
upvec [0] = evalue(mf -> ep [1]); |
1748 |
upvec [1] = evalue(mf -> ep [2]); |
1749 |
upvec [2] = evalue(mf -> ep [3]); |
1750 |
|
1751 |
if (mf -> fxp != &unitxf) { |
1752 |
multv3(upvec, upvec, mf -> fxp -> xfm); |
1753 |
nd.thick *= mf -> fxp -> sca; |
1754 |
} |
1755 |
|
1756 |
if (rayIn -> rox) { |
1757 |
multv3(upvec, upvec, rayIn -> rox -> f.xfm); |
1758 |
nd.thick *= rayIn -> rox -> f.sca; |
1759 |
} |
1760 |
|
1761 |
/* Perturb normal */ |
1762 |
raynormal(nd.pnorm, rayIn); |
1763 |
|
1764 |
/* Xform incident dir to local BSDF coords */ |
1765 |
err = SDcompXform(nd.toloc, nd.pnorm, upvec); |
1766 |
|
1767 |
if (!err) { |
1768 |
nd.vray [0] = -rayIn -> rdir [0]; |
1769 |
nd.vray [1] = -rayIn -> rdir [1]; |
1770 |
nd.vray [2] = -rayIn -> rdir [2]; |
1771 |
err = SDmapDir(nd.vray, nd.toloc, nd.vray); |
1772 |
} |
1773 |
|
1774 |
if (!err) |
1775 |
err = SDinvXform(nd.fromloc, nd.toloc); |
1776 |
|
1777 |
if (err) { |
1778 |
objerror(mat, WARNING, "Illegal orientation vector"); |
1779 |
return 0; |
1780 |
} |
1781 |
|
1782 |
/* Determine BSDF resolution */ |
1783 |
err = SDsizeBSDF(nd.sr_vpsa, nd.vray, NULL, SDqueryMin + SDqueryMax, nd.sd); |
1784 |
|
1785 |
if (err) |
1786 |
objerror(mat, USER, transSDError(err)); |
1787 |
|
1788 |
nd.sr_vpsa [0] = sqrt(nd.sr_vpsa [0]); |
1789 |
nd.sr_vpsa [1] = sqrt(nd.sr_vpsa [1]); |
1790 |
|
1791 |
/* Orient perturbed normal towards incident side */ |
1792 |
if (!hitFront) { |
1793 |
nd.pnorm [0] = -nd.pnorm [0]; |
1794 |
nd.pnorm [1] = -nd.pnorm [1]; |
1795 |
nd.pnorm [2] = -nd.pnorm [2]; |
1796 |
} |
1797 |
|
1798 |
/* Get scatter probabilities (weighted by pattern except for spec refl) |
1799 |
* prDiff, ptDiff: extra diffuse component in material def |
1800 |
* prDiffSD, ptDiffSD: diffuse (constant) component in SDF |
1801 |
* prSpecSD, ptSpecSD: non-diffuse ("specular") component in SDF |
1802 |
* albedo: sum of above, inverse absorption probability */ |
1803 |
prDiff = colorAvg(nd.rdiff); |
1804 |
ptDiff = colorAvg(nd.tdiff); |
1805 |
prDiffSD = patAlb * SDdirectHemi(nd.vray, SDsampDf | SDsampR, nd.sd); |
1806 |
ptDiffSD = patAlb * SDdirectHemi(nd.vray, SDsampDf | SDsampT, nd.sd); |
1807 |
prSpecSD = SDdirectHemi(nd.vray, SDsampSp | SDsampR, nd.sd); |
1808 |
ptSpecSD = patAlb * SDdirectHemi(nd.vray, SDsampSp | SDsampT, nd.sd); |
1809 |
albedo = prDiff + ptDiff + prDiffSD + ptDiffSD + prSpecSD + ptSpecSD; |
1810 |
|
1811 |
/* |
1812 |
if (albedo > 1) |
1813 |
objerror(mat, WARNING, "Invalid albedo"); |
1814 |
*/ |
1815 |
|
1816 |
/* Insert direct and indirect photon hits if diffuse component */ |
1817 |
if (prDiff + ptDiff + prDiffSD + ptDiffSD > FTINY) |
1818 |
addPhotons(rayIn); |
1819 |
|
1820 |
xi = xi2 = pmapRandom(rouletteState); |
1821 |
|
1822 |
if (xi > albedo) |
1823 |
/* Absorbtion */ |
1824 |
return 0; |
1825 |
|
1826 |
if ((xi -= prDiff) <= 0) { |
1827 |
/* Diffuse reflection (extra component in material def) */ |
1828 |
photonRay(rayIn, &rayOut, PMAP_DIFFREFL, nd.rdiff); |
1829 |
diffPhotonScatter(nd.pnorm, &rayOut); |
1830 |
} |
1831 |
|
1832 |
else if ((xi -= ptDiff) <= 0) { |
1833 |
/* Diffuse transmission (extra component in material def) */ |
1834 |
flipsurface(rayIn); |
1835 |
photonRay(rayIn, &rayOut, PMAP_DIFFTRANS, nd.tdiff); |
1836 |
diffPhotonScatter(nd.pnorm, &rayOut); |
1837 |
} |
1838 |
|
1839 |
else { /* Sample SDF */ |
1840 |
if ((xi -= prDiffSD) <= 0) { |
1841 |
/* Diffuse SDF reflection (constant component) */ |
1842 |
if ((err = SDsampBSDF(&bsdfVal, nd.vray, xi2, |
1843 |
SDsampDf | SDsampR, nd.sd))) |
1844 |
objerror(mat, USER, transSDError(err)); |
1845 |
|
1846 |
/* Apply pattern to spectral component */ |
1847 |
ccy2rgb(&bsdfVal.spec, bsdfVal.cieY, bsdfRGB); |
1848 |
multcolor(bsdfRGB, rayIn -> pcol); |
1849 |
photonRay(rayIn, &rayOut, PMAP_DIFFREFL, bsdfRGB); |
1850 |
} |
1851 |
|
1852 |
else if ((xi -= ptDiffSD) <= 0) { |
1853 |
/* Diffuse SDF transmission (constant component) */ |
1854 |
if ((err = SDsampBSDF(&bsdfVal, nd.vray, xi2, |
1855 |
SDsampDf | SDsampT, nd.sd))) |
1856 |
objerror(mat, USER, transSDError(err)); |
1857 |
|
1858 |
/* Apply pattern to spectral component */ |
1859 |
ccy2rgb(&bsdfVal.spec, bsdfVal.cieY, bsdfRGB); |
1860 |
multcolor(bsdfRGB, rayIn -> pcol); |
1861 |
addcolor(bsdfRGB, nd.tdiff); |
1862 |
flipsurface(rayIn); /* Necessary? */ |
1863 |
photonRay(rayIn, &rayOut, PMAP_DIFFTRANS, bsdfRGB); |
1864 |
} |
1865 |
|
1866 |
else if ((xi -= prSpecSD) <= 0) { |
1867 |
/* Non-diffuse ("specular") SDF reflection */ |
1868 |
if ((err = SDsampBSDF(&bsdfVal, nd.vray, xi2, |
1869 |
SDsampSp | SDsampR, nd.sd))) |
1870 |
objerror(mat, USER, transSDError(err)); |
1871 |
|
1872 |
ccy2rgb(&bsdfVal.spec, bsdfVal.cieY, bsdfRGB); |
1873 |
photonRay(rayIn, &rayOut, PMAP_SPECREFL, bsdfRGB); |
1874 |
} |
1875 |
|
1876 |
else { |
1877 |
/* Non-diffuse ("specular") SDF transmission */ |
1878 |
if ((err = SDsampBSDF(&bsdfVal, nd.vray, xi2, |
1879 |
SDsampSp | SDsampT, nd.sd))) |
1880 |
objerror(mat, USER, transSDError(err)); |
1881 |
|
1882 |
/* Apply pattern to spectral component */ |
1883 |
ccy2rgb(&bsdfVal.spec, bsdfVal.cieY, bsdfRGB); |
1884 |
multcolor(bsdfRGB, rayIn -> pcol); |
1885 |
flipsurface(rayIn); /* Necessary? */ |
1886 |
photonRay(rayIn, &rayOut, PMAP_SPECTRANS, bsdfRGB); |
1887 |
} |
1888 |
|
1889 |
/* Xform outgoing dir to world coords */ |
1890 |
if ((err = SDmapDir(rayOut.rdir, nd.fromloc, nd.vray))) { |
1891 |
objerror(mat, USER, transSDError(err)); |
1892 |
return 0; |
1893 |
} |
1894 |
} |
1895 |
|
1896 |
/* Clean up */ |
1897 |
SDfreeCache(nd.sd); |
1898 |
|
1899 |
tracePhoton(&rayOut); |
1900 |
return 0; |
1901 |
} |
1902 |
#endif |
1903 |
|
1904 |
|
1905 |
|
1906 |
static int lightPhotonScatter (OBJREC* mat, RAY* ray) |
1907 |
/* Light sources doan' reflect */ |
1908 |
{ |
1909 |
return 0; |
1910 |
} |
1911 |
|
1912 |
|
1913 |
|
1914 |
void initPhotonScatterFuncs () |
1915 |
/* Init photonScatter[] dispatch table */ |
1916 |
{ |
1917 |
int i; |
1918 |
|
1919 |
for (i = 0; i < NUMOTYPE; i++) |
1920 |
photonScatter [i] = o_default; |
1921 |
|
1922 |
photonScatter [MAT_LIGHT] = photonScatter [MAT_ILLUM] = |
1923 |
photonScatter [MAT_GLOW] = photonScatter [MAT_SPOT] = |
1924 |
lightPhotonScatter; |
1925 |
|
1926 |
photonScatter [MAT_PLASTIC] = photonScatter [MAT_METAL] = |
1927 |
photonScatter [MAT_TRANS] = normalPhotonScatter; |
1928 |
|
1929 |
photonScatter [MAT_PLASTIC2] = photonScatter [MAT_METAL2] = |
1930 |
photonScatter [MAT_TRANS2] = anisoPhotonScatter; |
1931 |
|
1932 |
photonScatter [MAT_DIELECTRIC] = photonScatter [MAT_INTERFACE] = |
1933 |
dielectricPhotonScatter; |
1934 |
|
1935 |
photonScatter [MAT_MIST] = mistPhotonScatter; |
1936 |
photonScatter [MAT_GLASS] = glassPhotonScatter; |
1937 |
photonScatter [MAT_CLIP] = clipPhotonScatter; |
1938 |
photonScatter [MAT_MIRROR] = mirrorPhotonScatter; |
1939 |
photonScatter [MIX_FUNC] = mx_funcPhotonScatter; |
1940 |
photonScatter [MIX_DATA] = mx_dataPhotonScatter; |
1941 |
photonScatter [MIX_PICT]= mx_pdataPhotonScatter; |
1942 |
|
1943 |
photonScatter [PAT_BDATA] = photonScatter [PAT_CDATA] = |
1944 |
photonScatter [PAT_BFUNC] = photonScatter [PAT_CFUNC] = |
1945 |
photonScatter [PAT_CPICT] = photonScatter [TEX_FUNC] = |
1946 |
photonScatter [TEX_DATA] = pattexPhotonScatter; |
1947 |
|
1948 |
photonScatter [MOD_ALIAS] = aliasPhotonScatter; |
1949 |
photonScatter [MAT_BSDF] = bsdfPhotonScatter; |
1950 |
} |