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root/radiance/ray/src/gen/mkillum2.c
Revision: 2.24
Committed: Wed Dec 5 20:07:34 2007 UTC (16 years, 4 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.23: +6 -6 lines
Log Message:
Improved BSDF resampling

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: mkillum2.c,v 2.23 2007/11/05 23:40:26 greg Exp $";
3 #endif
4 /*
5 * Routines to do the actual calculation for mkillum
6 */
7
8 #include <string.h>
9
10 #include "mkillum.h"
11 #include "face.h"
12 #include "cone.h"
13 #include "random.h"
14
15
16 COLORV * distarr = NULL; /* distribution array */
17 int distsiz = 0;
18
19
20 void
21 newdist( /* allocate & clear distribution array */
22 int siz
23 )
24 {
25 if (siz <= 0) {
26 if (distsiz > 0)
27 free((void *)distarr);
28 distarr = NULL;
29 distsiz = 0;
30 return;
31 }
32 if (distsiz < siz) {
33 if (distsiz > 0)
34 free((void *)distarr);
35 distarr = (COLORV *)malloc(sizeof(COLOR)*siz);
36 if (distarr == NULL)
37 error(SYSTEM, "out of memory in newdist");
38 distsiz = siz;
39 }
40 memset(distarr, '\0', sizeof(COLOR)*siz);
41 }
42
43
44 int
45 process_ray(RAY *r, int rv)
46 {
47 COLORV *colp;
48
49 if (rv == 0) /* no result ready */
50 return(0);
51 if (rv < 0)
52 error(USER, "ray tracing process died");
53 if (r->rno >= distsiz)
54 error(INTERNAL, "bad returned index in process_ray");
55 colp = &distarr[r->rno * 3];
56 addcolor(colp, r->rcol);
57 return(1);
58 }
59
60
61 void
62 raysamp( /* queue a ray sample */
63 int ndx,
64 FVECT org,
65 FVECT dir
66 )
67 {
68 RAY myRay;
69 int rv;
70
71 if ((ndx < 0) | (ndx >= distsiz))
72 error(INTERNAL, "bad index in raysamp");
73 VCOPY(myRay.rorg, org);
74 VCOPY(myRay.rdir, dir);
75 myRay.rmax = .0;
76 rayorigin(&myRay, PRIMARY, NULL, NULL);
77 myRay.rno = ndx;
78 /* queue ray, check result */
79 process_ray(&myRay, ray_pqueue(&myRay));
80 }
81
82
83 void
84 rayclean() /* finish all pending rays */
85 {
86 RAY myRay;
87
88 while (process_ray(&myRay, ray_presult(&myRay, 0)))
89 ;
90 }
91
92
93 static void
94 mkaxes( /* compute u and v to go with n */
95 FVECT u,
96 FVECT v,
97 FVECT n
98 )
99 {
100 register int i;
101
102 v[0] = v[1] = v[2] = 0.0;
103 for (i = 0; i < 3; i++)
104 if (n[i] < 0.6 && n[i] > -0.6)
105 break;
106 v[i] = 1.0;
107 fcross(u, v, n);
108 normalize(u);
109 fcross(v, n, u);
110 }
111
112
113 static void
114 rounddir( /* compute uniform spherical direction */
115 register FVECT dv,
116 double alt,
117 double azi
118 )
119 {
120 double d1, d2;
121
122 dv[2] = 1. - 2.*alt;
123 d1 = sqrt(1. - dv[2]*dv[2]);
124 d2 = 2.*PI * azi;
125 dv[0] = d1*cos(d2);
126 dv[1] = d1*sin(d2);
127 }
128
129
130 void
131 flatdir( /* compute uniform hemispherical direction */
132 FVECT dv,
133 double alt,
134 double azi
135 )
136 {
137 double d1, d2;
138
139 d1 = sqrt(alt);
140 d2 = 2.*PI * azi;
141 dv[0] = d1*cos(d2);
142 dv[1] = d1*sin(d2);
143 dv[2] = sqrt(1. - alt);
144 }
145
146
147 int
148 my_default( /* default illum action */
149 OBJREC *ob,
150 struct illum_args *il,
151 char *nm
152 )
153 {
154 sprintf(errmsg, "(%s): cannot make illum for %s \"%s\"",
155 nm, ofun[ob->otype].funame, ob->oname);
156 error(WARNING, errmsg);
157 printobj(il->altmat, ob);
158 return(1);
159 }
160
161
162 int
163 my_face( /* make an illum face */
164 OBJREC *ob,
165 struct illum_args *il,
166 char *nm
167 )
168 {
169 #define MAXMISS (5*n*il->nsamps)
170 int dim[2];
171 int n, nalt, nazi, h, alti;
172 double sp[2], r1, r2;
173 FVECT dn, org, dir;
174 FVECT u, v;
175 double ur[2], vr[2];
176 MAT4 xfm;
177 int nmisses;
178 FACE *fa;
179 register int i, j;
180 /* get/check arguments */
181 fa = getface(ob);
182 if (fa->area == 0.0) {
183 freeface(ob);
184 return(my_default(ob, il, nm));
185 }
186 /* set up sampling */
187 if (il->sd != NULL) {
188 if (!getBSDF_xfm(xfm, fa->norm, il->udir)) {
189 objerror(ob, WARNING, "illegal up direction");
190 freeface(ob);
191 return(my_default(ob, il, nm));
192 }
193 n = il->sd->ninc;
194 } else {
195 if (il->sampdens <= 0) {
196 nalt = nazi = 1; /* diffuse assumption */
197 } else {
198 n = PI * il->sampdens;
199 nalt = sqrt(n/PI) + .5;
200 nazi = PI*nalt + .5;
201 }
202 n = nazi*nalt;
203 }
204 newdist(n);
205 /* take first edge >= sqrt(area) */
206 for (j = fa->nv-1, i = 0; i < fa->nv; j = i++) {
207 u[0] = VERTEX(fa,i)[0] - VERTEX(fa,j)[0];
208 u[1] = VERTEX(fa,i)[1] - VERTEX(fa,j)[1];
209 u[2] = VERTEX(fa,i)[2] - VERTEX(fa,j)[2];
210 if ((r1 = DOT(u,u)) >= fa->area-FTINY)
211 break;
212 }
213 if (i < fa->nv) { /* got one! -- let's align our axes */
214 r2 = 1.0/sqrt(r1);
215 u[0] *= r2; u[1] *= r2; u[2] *= r2;
216 fcross(v, fa->norm, u);
217 } else /* oh well, we'll just have to wing it */
218 mkaxes(u, v, fa->norm);
219 /* now, find limits in (u,v) coordinates */
220 ur[0] = vr[0] = FHUGE;
221 ur[1] = vr[1] = -FHUGE;
222 for (i = 0; i < fa->nv; i++) {
223 r1 = DOT(VERTEX(fa,i),u);
224 if (r1 < ur[0]) ur[0] = r1;
225 if (r1 > ur[1]) ur[1] = r1;
226 r2 = DOT(VERTEX(fa,i),v);
227 if (r2 < vr[0]) vr[0] = r2;
228 if (r2 > vr[1]) vr[1] = r2;
229 }
230 dim[0] = random();
231 /* sample polygon */
232 nmisses = 0;
233 for (dim[1] = 0; dim[1] < n; dim[1]++)
234 for (i = 0; i < il->nsamps; i++) {
235 /* randomize direction */
236 h = ilhash(dim, 2) + i;
237 if (il->sd != NULL) {
238 r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
239 } else {
240 multisamp(sp, 2, urand(h));
241 alti = dim[1]/nazi;
242 r1 = (alti + sp[0])/nalt;
243 r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
244 flatdir(dn, r1, r2);
245 for (j = 0; j < 3; j++)
246 dir[j] = -dn[0]*u[j] - dn[1]*v[j] -
247 dn[2]*fa->norm[j];
248 }
249 /* randomize location */
250 do {
251 multisamp(sp, 2, urand(h+4862+nmisses));
252 r1 = ur[0] + (ur[1]-ur[0]) * sp[0];
253 r2 = vr[0] + (vr[1]-vr[0]) * sp[1];
254 for (j = 0; j < 3; j++)
255 org[j] = r1*u[j] + r2*v[j]
256 + fa->offset*fa->norm[j];
257 } while (!inface(org, fa) && nmisses++ < MAXMISS);
258 if (nmisses > MAXMISS) {
259 objerror(ob, WARNING, "bad aspect");
260 rayclean();
261 freeface(ob);
262 return(my_default(ob, il, nm));
263 }
264 if (il->sd != NULL && DOT(dir, fa->norm) < -FTINY)
265 r1 = -1.0001*il->thick - .0001;
266 else
267 r1 = .0001;
268 for (j = 0; j < 3; j++)
269 org[j] += r1*fa->norm[j];
270 /* send sample */
271 raysamp(dim[1], org, dir);
272 }
273 rayclean();
274 if (il->sd != NULL) { /* run distribution through BSDF */
275 nalt = sqrt(il->sd->nout/PI) + .5;
276 nazi = PI*nalt + .5;
277 redistribute(il->sd, nalt, nazi, u, v, fa->norm, xfm);
278 }
279 /* write out the face and its distribution */
280 if (average(il, distarr, n)) {
281 if (il->sampdens > 0)
282 flatout(il, distarr, nalt, nazi, u, v, fa->norm);
283 illumout(il, ob);
284 } else
285 printobj(il->altmat, ob);
286 /* clean up */
287 freeface(ob);
288 return(0);
289 #undef MAXMISS
290 }
291
292
293 int
294 my_sphere( /* make an illum sphere */
295 register OBJREC *ob,
296 struct illum_args *il,
297 char *nm
298 )
299 {
300 int dim[3];
301 int n, nalt, nazi;
302 double sp[4], r1, r2, r3;
303 FVECT org, dir;
304 FVECT u, v;
305 register int i, j;
306 /* check arguments */
307 if (ob->oargs.nfargs != 4)
308 objerror(ob, USER, "bad # of arguments");
309 /* set up sampling */
310 if (il->sampdens <= 0)
311 nalt = nazi = 1;
312 else {
313 n = 4.*PI * il->sampdens;
314 nalt = sqrt(2./PI*n) + .5;
315 nazi = PI/2.*nalt + .5;
316 }
317 if (il->sd != NULL)
318 objerror(ob, WARNING, "BSDF ignored");
319 n = nalt*nazi;
320 newdist(n);
321 dim[0] = random();
322 /* sample sphere */
323 for (dim[1] = 0; dim[1] < nalt; dim[1]++)
324 for (dim[2] = 0; dim[2] < nazi; dim[2]++)
325 for (i = 0; i < il->nsamps; i++) {
326 /* next sample point */
327 multisamp(sp, 4, urand(ilhash(dim,3)+i));
328 /* random direction */
329 r1 = (dim[1] + sp[0])/nalt;
330 r2 = (dim[2] + sp[1] - .5)/nazi;
331 rounddir(dir, r1, r2);
332 /* random location */
333 mkaxes(u, v, dir); /* yuck! */
334 r3 = sqrt(sp[2]);
335 r2 = 2.*PI*sp[3];
336 r1 = r3*ob->oargs.farg[3]*cos(r2);
337 r2 = r3*ob->oargs.farg[3]*sin(r2);
338 r3 = ob->oargs.farg[3]*sqrt(1.01-r3*r3);
339 for (j = 0; j < 3; j++) {
340 org[j] = ob->oargs.farg[j] + r1*u[j] + r2*v[j] +
341 r3*dir[j];
342 dir[j] = -dir[j];
343 }
344 /* send sample */
345 raysamp(dim[1]*nazi+dim[2], org, dir);
346 }
347 rayclean();
348 /* write out the sphere and its distribution */
349 if (average(il, distarr, n)) {
350 if (il->sampdens > 0)
351 roundout(il, distarr, nalt, nazi);
352 else
353 objerror(ob, WARNING, "diffuse distribution");
354 illumout(il, ob);
355 } else
356 printobj(il->altmat, ob);
357 /* clean up */
358 return(1);
359 }
360
361
362 int
363 my_ring( /* make an illum ring */
364 OBJREC *ob,
365 struct illum_args *il,
366 char *nm
367 )
368 {
369 int dim[2];
370 int n, nalt, nazi, alti;
371 double sp[2], r1, r2, r3;
372 int h;
373 FVECT dn, org, dir;
374 FVECT u, v;
375 MAT4 xfm;
376 CONE *co;
377 register int i, j;
378 /* get/check arguments */
379 co = getcone(ob, 0);
380 /* set up sampling */
381 if (il->sd != NULL) {
382 if (!getBSDF_xfm(xfm, co->ad, il->udir)) {
383 objerror(ob, WARNING, "illegal up direction");
384 freecone(ob);
385 return(my_default(ob, il, nm));
386 }
387 n = il->sd->ninc;
388 } else {
389 if (il->sampdens <= 0) {
390 nalt = nazi = 1; /* diffuse assumption */
391 } else {
392 n = PI * il->sampdens;
393 nalt = sqrt(n/PI) + .5;
394 nazi = PI*nalt + .5;
395 }
396 n = nazi*nalt;
397 }
398 newdist(n);
399 mkaxes(u, v, co->ad);
400 dim[0] = random();
401 /* sample disk */
402 for (dim[1] = 0; dim[1] < n; dim[1]++)
403 for (i = 0; i < il->nsamps; i++) {
404 /* next sample point */
405 h = ilhash(dim,2) + i;
406 /* randomize direction */
407 if (il->sd != NULL) {
408 r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
409 } else {
410 multisamp(sp, 2, urand(h));
411 alti = dim[1]/nazi;
412 r1 = (alti + sp[0])/nalt;
413 r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
414 flatdir(dn, r1, r2);
415 for (j = 0; j < 3; j++)
416 dir[j] = -dn[0]*u[j] - dn[1]*v[j] - dn[2]*co->ad[j];
417 }
418 /* randomize location */
419 multisamp(sp, 2, urand(h+8371));
420 r3 = sqrt(CO_R0(co)*CO_R0(co) +
421 sp[0]*(CO_R1(co)*CO_R1(co) - CO_R0(co)*CO_R0(co)));
422 r2 = 2.*PI*sp[1];
423 r1 = r3*cos(r2);
424 r2 = r3*sin(r2);
425 if (il->sd != NULL && DOT(dir, co->ad) < -FTINY)
426 r3 = -1.0001*il->thick - .0001;
427 else
428 r3 = .0001;
429 for (j = 0; j < 3; j++)
430 org[j] = CO_P0(co)[j] + r1*u[j] + r2*v[j] +
431 r3*co->ad[j];
432 /* send sample */
433 raysamp(dim[1], org, dir);
434 }
435 rayclean();
436 if (il->sd != NULL) { /* run distribution through BSDF */
437 nalt = sqrt(il->sd->nout/PI) + .5;
438 nazi = PI*nalt + .5;
439 redistribute(il->sd, nalt, nazi, u, v, co->ad, xfm);
440 }
441 /* write out the ring and its distribution */
442 if (average(il, distarr, n)) {
443 if (il->sampdens > 0)
444 flatout(il, distarr, nalt, nazi, u, v, co->ad);
445 illumout(il, ob);
446 } else
447 printobj(il->altmat, ob);
448 /* clean up */
449 freecone(ob);
450 return(1);
451 }