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root/radiance/ray/src/gen/genssky.c
Revision: 2.6
Committed: Wed Oct 9 17:22:42 2024 UTC (7 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.5: +59 -25 lines
Log Message:
feat(genssky): Taoning added -L option to specify horiz. illuminance values

File Contents

# Content
1 #include "color.h"
2 #ifndef lint
3 static const char RCSid[] =
4 "$Id: genssky.c,v 2.5 2024/08/19 18:07:44 greg Exp $";
5 #endif
6 /* Main function for generating spectral sky */
7 /* Cloudy sky computed as weight average of clear and cie overcast sky */
8
9 #include "atmos.h"
10 #include "copyright.h"
11 #include "resolu.h"
12 #include "rtio.h"
13 #include <ctype.h>
14 #ifdef _WIN32
15 #include <windows.h>
16 #else
17 #include <errno.h>
18 #include <sys/stat.h>
19 #include <sys/types.h>
20 #endif
21
22 char *progname;
23
24 const double ARCTIC_LAT = 67.;
25 const double TROPIC_LAT = 23.;
26 const int SUMMER_START = 4;
27 const int SUMMER_END = 9;
28 const double GNORM = 0.777778;
29
30 const double D65EFF = 203.; /* standard illuminant D65 */
31
32 /* Mean normalized relative daylight spectra where CCT = 6415K for overcast; */
33 const double D6415[NSSAMP] = {0.63231, 1.06171, 1.00779, 1.36423, 1.34133,
34 1.27258, 1.26276, 1.26352, 1.22201, 1.13246,
35 1.0434, 1.05547, 0.98212, 0.94445, 0.9722,
36 0.82387, 0.87853, 0.82559, 0.75111, 0.78925};
37
38 /* European and North American zones */
39 struct {
40 char zname[8]; /* time zone name (all caps) */
41 float zmer; /* standard meridian */
42 } tzone[] = {{"YST", 135}, {"YDT", 120}, {"PST", 120}, {"PDT", 105},
43 {"MST", 105}, {"MDT", 90}, {"CST", 90}, {"CDT", 75},
44 {"EST", 75}, {"EDT", 60}, {"AST", 60}, {"ADT", 45},
45 {"NST", 52.5}, {"NDT", 37.5}, {"GMT", 0}, {"BST", -15},
46 {"CET", -15}, {"CEST", -30}, {"EET", -30}, {"EEST", -45},
47 {"AST", -45}, {"ADT", -60}, {"GST", -60}, {"GDT", -75},
48 {"IST", -82.5}, {"IDT", -97.5}, {"JST", -135}, {"NDT", -150},
49 {"NZST", -180}, {"NZDT", -195}, {"", 0}};
50
51 static int make_directory(const char *path) {
52 #ifdef _WIN32
53 if (CreateDirectory(path, NULL) || GetLastError() == ERROR_ALREADY_EXISTS) {
54 return 1;
55 }
56 return 0;
57 #else
58 if (mkdir(path, 0777) == 0 || errno == EEXIST) {
59 return 1;
60 }
61 return 0;
62 #endif
63 }
64
65 inline static float deg2rad(float deg) { return deg * (PI / 180.); }
66
67 static int cvthour(char *hs, int *tsolar, double *hour) {
68 char *cp = hs;
69 int i, j;
70
71 if ((*tsolar = *cp == '+'))
72 cp++; /* solar time? */
73 while (isdigit(*cp))
74 cp++;
75 if (*cp == ':')
76 *hour = atoi(hs) + atoi(++cp) / 60.0;
77 else {
78 *hour = atof(hs);
79 if (*cp == '.')
80 cp++;
81 }
82 while (isdigit(*cp))
83 cp++;
84 if (!*cp)
85 return (0);
86 if (*tsolar || !isalpha(*cp)) {
87 fprintf(stderr, "%s: bad time format: %s\n", progname, hs);
88 exit(1);
89 }
90 i = 0;
91 do {
92 for (j = 0; cp[j]; j++)
93 if (toupper(cp[j]) != tzone[i].zname[j])
94 break;
95 if (!cp[j] && !tzone[i].zname[j]) {
96 s_meridian = tzone[i].zmer * (PI / 180);
97 return (1);
98 }
99 } while (tzone[i++].zname[0]);
100
101 fprintf(stderr, "%s: unknown time zone: %s\n", progname, cp);
102 fprintf(stderr, "Known time zones:\n\t%s", tzone[0].zname);
103 for (i = 1; tzone[i].zname[0]; i++)
104 fprintf(stderr, " %s", tzone[i].zname);
105 putc('\n', stderr);
106 exit(1);
107 }
108
109 static void basename(const char *path, char *output, size_t outsize) {
110 const char *last_slash = strrchr(path, '/');
111 const char *last_backslash = strrchr(path, '\\');
112 const char *filename = path;
113 const char *last_dot;
114
115 if (last_slash && last_backslash) {
116 filename =
117 (last_slash > last_backslash) ? last_slash + 1 : last_backslash + 1;
118 } else if (last_slash) {
119 filename = last_slash + 1;
120 } else if (last_backslash) {
121 filename = last_backslash + 1;
122 }
123
124 last_dot = strrchr(filename, '.');
125 if (last_dot) {
126 size_t length = last_dot - filename;
127 if (length < outsize) {
128 strncpy(output, filename, length);
129 output[length] = '\0';
130 } else {
131 strncpy(output, filename, outsize - 1);
132 output[outsize - 1] = '\0';
133 }
134 }
135 }
136
137 static char *join_paths(const char *path1, const char *path2) {
138 size_t len1 = strlen(path1);
139 size_t len2 = strlen(path2);
140 int need_separator = (path1[len1 - 1] != DIRSEP);
141
142 char *result = malloc(len1 + len2 + (need_separator ? 2 : 1));
143 if (!result)
144 return NULL;
145
146 strcpy(result, path1);
147 if (need_separator) {
148 result[len1] = DIRSEP;
149 len1++;
150 }
151 strcpy(result + len1, path2);
152
153 return result;
154 }
155
156 static inline double wmean2(const double a, const double b, const double x) {
157 return a * (1 - x) + b * x;
158 }
159
160 static inline double wmean(const double a, const double x, const double b,
161 const double y) {
162 return (a * x + b * y) / (a + b);
163 }
164
165 static double get_overcast_zenith_brightness(const double sundir[3]) {
166 double zenithbr;
167 if (sundir[2] < 0) {
168 zenithbr = 0;
169 } else {
170 zenithbr = (8.6 * sundir[2] + .123) * 1000.0 / D65EFF;
171 }
172 return zenithbr;
173 }
174
175 /* from gensky.c */
176 static double get_overcast_brightness(const double dz, const double zenithbr) {
177 double groundbr = zenithbr * GNORM;
178 return wmean(pow(dz + 1.01, 10), zenithbr * (1 + 2 * dz) / 3,
179 pow(dz + 1.01, -10), groundbr);
180 }
181
182 static void write_header(const int argc, char **argv, const double cloud_cover,
183 const double grefl, const int res) {
184 int i;
185 printf("# ");
186 for (i = 0; i < argc; i++) {
187 printf("%s ", argv[i]);
188 }
189 printf("\n");
190 printf(
191 "#Cloud cover: %g\n#Ground reflectance: %g\n#Sky map resolution: %d\n\n",
192 cloud_cover, grefl, res);
193 }
194
195 static void write_rad(const double *sun_radiance, const double intensity,
196 const FVECT sundir, const char *ddir,
197 const char *skyfile) {
198 if (sundir[2] > 0) {
199 printf("void spectrum sunrad\n0\n0\n22 380 780 ");
200 int i;
201 for (i = 0; i < NSSAMP; ++i) {
202 printf("%.3f ", sun_radiance[i]);
203 }
204 printf("\n\nsunrad light solar\n0\n0\n3 %.1f %.1f %.1f\n\n", intensity,
205 intensity, intensity);
206 printf("solar source sun\n0\n0\n4 %f %f %f 0.533\n\n", sundir[0], sundir[1],
207 sundir[2]);
208 }
209 printf("void specpict skyfunc\n5 noop %s . 'Atan2(Dy,Dx)/PI+1' "
210 "'1-Acos(Dz)/PI'\n0\n0\n\n",
211 skyfile);
212 }
213
214 static void write_hsr_header(FILE *fp, RESOLU *res) {
215 float wvsplit[4] = {380, 480, 588, 780};
216 newheader("RADIANCE", fp);
217 fputncomp(NSSAMP, fp);
218 fputwlsplit(wvsplit, fp);
219 fputformat(SPECFMT, fp);
220 fputc('\n', fp);
221 fputsresolu(res, fp);
222 }
223
224 static inline float frac(float x) { return x - floor(x); }
225
226 int gen_spect_sky(DATARRAY *tau_clear, DATARRAY *scat_clear,
227 DATARRAY *scat1m_clear, DATARRAY *irrad_clear,
228 const double cloud_cover, const FVECT sundir,
229 const double grefl, const int res, const char *outname,
230 const char *ddir, const double dirnorm, const double difhor) {
231 char skyfile[PATH_MAX];
232 if (!snprintf(skyfile, sizeof(skyfile), "%s%c%s_sky.hsr", ddir, DIRSEP,
233 outname)) {
234 fprintf(stderr, "Error setting sky file name\n");
235 return 0;
236 };
237 int xres = res;
238 int yres = xres / 2;
239 RESOLU rs = {PIXSTANDARD, xres, yres};
240 FILE *skyfp = fopen(skyfile, "w");
241 write_hsr_header(skyfp, &rs);
242
243 CNDX[3] = NSSAMP;
244
245 FVECT view_point = {0, 0, ER + 10};
246 const double radius = VLEN(view_point);
247 const double sun_ct = fdot(view_point, sundir) / radius;
248
249 double overcast_zenithbr = get_overcast_zenith_brightness(sundir);
250 double overcast_grndbr = overcast_zenithbr * GNORM;
251
252 double dif_ratio = 1;
253 if (difhor > 0) {
254 DATARRAY *indirect_irradiance_clear = get_indirect_irradiance(irrad_clear, radius, sun_ct);
255 double overcast_ghi = overcast_zenithbr * 7.0 * PI / 9.0;
256 double diffuse_irradiance = 0;
257 int l;
258 for (l = 0; l < NSSAMP; ++l) {
259 diffuse_irradiance += indirect_irradiance_clear->arr.d[l] * 20; /* 20nm interval */
260 }
261 free(indirect_irradiance_clear);
262 diffuse_irradiance = wmean2(diffuse_irradiance, overcast_ghi, cloud_cover);
263 dif_ratio = difhor / WHTEFFICACY / diffuse_irradiance / 1.15; /* fudge */
264 }
265 int i, j, k;
266 for (j = 0; j < yres; ++j) {
267 for (i = 0; i < xres; ++i) {
268 SCOLOR radiance = {0};
269 SCOLR sky_sclr = {0};
270
271 float px = i / (xres - 1.0);
272 float py = j / (yres - 1.0);
273 float lambda = ((1 - py) * PI) - (PI / 2.0);
274 float phi = (px * 2.0 * PI) - PI;
275
276 FVECT rdir = {cos(lambda) * cos(phi), cos(lambda) * sin(phi),
277 sin(lambda)};
278
279 const double mu = fdot(view_point, rdir) / radius;
280 const double nu = fdot(rdir, sundir);
281
282 /* hit ground */
283 if (rdir[2] < 0) {
284 get_ground_radiance(tau_clear, scat_clear, scat1m_clear, irrad_clear,
285 view_point, rdir, radius, mu, sun_ct, nu, grefl,
286 sundir, radiance);
287 } else {
288 get_sky_radiance(scat_clear, scat1m_clear, radius, mu, sun_ct, nu,
289 radiance);
290 }
291
292 for (k = 0; k < NSSAMP; ++k) {
293 radiance[k] *= WVLSPAN;
294 }
295
296 if (cloud_cover > 0) {
297 double skybr = get_overcast_brightness(rdir[2], overcast_zenithbr);
298 if (rdir[2] < 0) {
299 for (k = 0; k < NSSAMP; ++k) {
300 radiance[k] = wmean2(radiance[k], overcast_grndbr * D6415[k], cloud_cover);
301 }
302 } else {
303 for (k = 0; k < NSSAMP; ++k) {
304 radiance[k] = wmean2(radiance[k], skybr * D6415[k], cloud_cover);
305 }
306 }
307 }
308
309 for (k = 0; k < NSSAMP; ++k) {
310 radiance[k] *= dif_ratio;
311 }
312
313 scolor2scolr(sky_sclr, radiance, NSSAMP);
314 putbinary(sky_sclr, LSCOLR, 1, skyfp);
315 }
316 }
317 fclose(skyfp);
318
319 /* Get solar radiance */
320 double sun_radiance[NSSAMP] = {0};
321 get_solar_radiance(tau_clear, scat_clear, scat1m_clear, sundir, radius,
322 sun_ct, sun_radiance);
323 if (cloud_cover > 0) {
324 double skybr = get_overcast_brightness(sundir[2], overcast_zenithbr);
325 int i;
326 for (i = 0; i < NSSAMP; ++i) {
327 sun_radiance[i] =
328 wmean2(sun_radiance[i], D6415[i] * skybr / WVLSPAN, cloud_cover);
329 }
330 }
331
332 /* Normalize */
333 double sum = 0.0;
334 for (i = 0; i < NSSAMP; ++i) {
335 sum += sun_radiance[i];
336 }
337 double mean = sum / NSSAMP;
338 for (i = 0; i < NSSAMP; ++i) {
339 sun_radiance[i] /= mean;
340 }
341 double intensity = mean * WVLSPAN;
342 if (dirnorm > 0) {
343 intensity = dirnorm / SOLOMG / WHTEFFICACY;
344 }
345
346 write_rad(sun_radiance, intensity, sundir, ddir, skyfile);
347 return 1;
348 }
349
350 static DpPaths get_dppaths(const char *dir, const double aod, const char *mname,
351 const char *tag) {
352 DpPaths paths;
353
354 snprintf(paths.tau, PATH_MAX, "%s%ctau_%s_%s_%.2f.dat", dir, DIRSEP, tag,
355 mname, aod);
356 snprintf(paths.scat, PATH_MAX, "%s%cscat_%s_%s_%.2f.dat", dir, DIRSEP, tag,
357 mname, aod);
358 snprintf(paths.scat1m, PATH_MAX, "%s%cscat1m_%s_%s_%.2f.dat", dir, DIRSEP,
359 tag, mname, aod);
360 snprintf(paths.irrad, PATH_MAX, "%s%cirrad_%s_%s_%.2f.dat", dir, DIRSEP, tag,
361 mname, aod);
362
363 return paths;
364 }
365
366 static void set_rayleigh_density_profile(Atmosphere *atmos, char *tag,
367 const int is_summer,
368 const double s_latitude) {
369 if (fabs(s_latitude * 180.0 / PI) > ARCTIC_LAT) {
370 tag[0] = 's';
371 if (is_summer) {
372 tag[1] = 's';
373 atmos->rayleigh_density.layers[0].exp_scale = -1.0 / HR_SS;
374 atmos->beta_r0 = BR0_SS;
375 } else {
376 tag[1] = 'w';
377 atmos->rayleigh_density.layers[0].exp_scale = -1.0 / HR_SW;
378 atmos->beta_r0 = BR0_SW;
379 }
380 } else if (fabs(s_latitude * 180.0 / PI) > TROPIC_LAT) {
381 tag[0] = 'm';
382 if (is_summer) {
383 tag[1] = 's';
384 atmos->rayleigh_density.layers[0].exp_scale = -1.0 / HR_MS;
385 atmos->beta_r0 = BR0_MS;
386 } else {
387 tag[1] = 'w';
388 atmos->rayleigh_density.layers[0].exp_scale = -1.0 / HR_MW;
389 atmos->beta_r0 = BR0_MW;
390 }
391 } else {
392 tag[0] = 't';
393 tag[1] = 'r';
394 atmos->rayleigh_density.layers[0].exp_scale = -1.0 / HR_T;
395 atmos->beta_r0 = BR0_T;
396 }
397 tag[2] = '\0';
398 }
399
400 static Atmosphere init_atmos(const double aod, const double grefl) {
401 Atmosphere atmos = {.ozone_density = {.layers =
402 {
403 {.width = 25000.0,
404 .exp_term = 0.0,
405 .exp_scale = 0.0,
406 .linear_term = 1.0 / 15000.0,
407 .constant_term = -2.0 / 3.0},
408 {.width = AH,
409 .exp_term = 0.0,
410 .exp_scale = 0.0,
411 .linear_term = -1.0 / 15000.0,
412 .constant_term = 8.0 / 3.0},
413 }},
414 .rayleigh_density = {.layers =
415 {
416 {.width = AH,
417 .exp_term = 1.0,
418 .exp_scale = -1.0 / HR_MS,
419 .linear_term = 0.0,
420 .constant_term = 0.0},
421 }},
422 .beta_r0 = BR0_MS,
423 .beta_scale = aod / AOD0_CA,
424 .beta_m = NULL,
425 .grefl = grefl};
426 return atmos;
427 }
428
429 int main(int argc, char *argv[]) {
430 progname = argv[0];
431 int month, day;
432 double hour;
433 FVECT sundir;
434 int num_threads = 1;
435 int sorder = 4;
436 int year = 0;
437 int tsolar = 0;
438 int got_meridian = 0;
439 double grefl = 0.2;
440 double ccover = 0.0;
441 int res = 64;
442 double aod = AOD0_CA;
443 char *outname = "out";
444 char *mie_path = getpath("mie_ca.dat", getrlibpath(), R_OK);
445 char mie_name[20] = "mie_ca";
446 char lstag[3];
447 char *ddir = ".";
448 int i;
449 double dirnorm = 0; /* direct normal illuminance */
450 double difhor = 0; /* diffuse horizontal illuminance */
451
452 if (argc == 2 && !strcmp(argv[1], "-defaults")) {
453 printf("-i %d\t\t\t\t#scattering order\n", sorder);
454 printf("-g %f\t\t\t#ground reflectance\n", grefl);
455 printf("-c %f\t\t\t#cloud cover\n", ccover);
456 printf("-r %d\t\t\t\t#image resolution\n", res);
457 printf("-d %f\t\t\t#broadband aerosol optical depth\n", AOD0_CA);
458 printf("-f %s\t\t\t\t#output name (-f)\n", outname);
459 printf("-p %s\t\t\t\t#atmos data directory\n", ddir);
460 exit(0);
461 }
462
463 if (argc < 4) {
464 fprintf(stderr,
465 "Usage: %s month day hour -y year -a lat -o lon -m tz -d aod -r "
466 "res -n nproc -c ccover -l mie -L dirnorm_illum difhor_illum "
467 "-g grefl -f outpath\n",
468 argv[0]);
469 return 0;
470 }
471
472 month = atoi(argv[1]);
473 if (month < 1 || month > 12) {
474 fprintf(stderr, "bad month");
475 exit(1);
476 }
477 day = atoi(argv[2]);
478 if (day < 1 || day > 31) {
479 fprintf(stderr, "bad month");
480 exit(1);
481 }
482 got_meridian = cvthour(argv[3], &tsolar, &hour);
483
484 if (!compute_sundir(year, month, day, hour, tsolar, sundir)) {
485 fprintf(stderr, "Cannot compute solar angle\n");
486 exit(1);
487 }
488
489 for (i = 4; i < argc; i++) {
490 if (argv[i][0] == '-') {
491 switch (argv[i][1]) {
492 case 'a':
493 s_latitude = atof(argv[++i]) * (PI / 180.0);
494 break;
495 case 'c':
496 ccover = atof(argv[++i]);
497 break;
498 case 'd':
499 aod = atof(argv[++i]);
500 break;
501 case 'f':
502 outname = argv[++i];
503 break;
504 case 'g':
505 grefl = atof(argv[++i]);
506 break;
507 case 'i':
508 sorder = atoi(argv[++i]);
509 break;
510 case 'l':
511 mie_path = argv[++i];
512 basename(mie_path, mie_name, sizeof(mie_name));
513 break;
514 case 'm':
515 if (got_meridian) {
516 ++i;
517 break;
518 }
519 s_meridian = atof(argv[++i]) * (PI / 180.0);
520 break;
521 case 'n':
522 num_threads = atoi(argv[++i]);
523 break;
524 case 'o':
525 s_longitude = atof(argv[++i]) * (PI / 180.0);
526 break;
527 case 'L':
528 dirnorm = atof(argv[++i]);
529 difhor = atof(argv[++i]);
530 break;
531 case 'p':
532 ddir = argv[++i];
533 break;
534 case 'r':
535 res = atoi(argv[++i]);
536 break;
537 case 'y':
538 year = atoi(argv[++i]);
539 break;
540 default:
541 fprintf(stderr, "Unknown option %s\n", argv[i]);
542 exit(1);
543 }
544 }
545 }
546 if (year && (year < 1950) | (year > 2050))
547 fprintf(stderr, "%s: warning - year should be in range 1950-2050\n",
548 progname);
549 if (month && !tsolar && fabs(s_meridian - s_longitude) > 45 * PI / 180)
550 fprintf(stderr,
551 "%s: warning - %.1f hours btwn. standard meridian and longitude\n",
552 progname, (s_longitude - s_meridian) * 12 / PI);
553
554 Atmosphere clear_atmos = init_atmos(aod, grefl);
555
556 int is_summer = (month >= SUMMER_START && month <= SUMMER_END);
557 if (s_latitude < 0) {
558 is_summer = !is_summer;
559 }
560 set_rayleigh_density_profile(&clear_atmos, lstag, is_summer, s_latitude);
561
562 /* Load mie density data */
563 DATARRAY *mie_dp = getdata(mie_path);
564 if (mie_dp == NULL) {
565 fprintf(stderr, "Error reading mie data\n");
566 return 0;
567 }
568 clear_atmos.beta_m = mie_dp;
569
570 char gsdir[PATH_MAX];
571 size_t siz = strlen(ddir);
572 if (ISDIRSEP(ddir[siz - 1]))
573 ddir[siz - 1] = '\0';
574 snprintf(gsdir, PATH_MAX, "%s%catmos_data", ddir, DIRSEP);
575 if (!make_directory(gsdir)) {
576 fprintf(stderr, "Failed creating atmos_data directory");
577 exit(1);
578 }
579 DpPaths clear_paths = get_dppaths(gsdir, aod, mie_name, lstag);
580
581 if (getpath(clear_paths.tau, ".", R_OK) == NULL ||
582 getpath(clear_paths.scat, ".", R_OK) == NULL ||
583 getpath(clear_paths.scat1m, ".", R_OK) == NULL ||
584 getpath(clear_paths.irrad, ".", R_OK) == NULL) {
585 printf("# Pre-computing...\n");
586 if (!precompute(sorder, clear_paths, &clear_atmos, num_threads)) {
587 fprintf(stderr, "Pre-compute failed\n");
588 return 0;
589 }
590 }
591
592 DATARRAY *tau_clear_dp = getdata(clear_paths.tau);
593 DATARRAY *irrad_clear_dp = getdata(clear_paths.irrad);
594 DATARRAY *scat_clear_dp = getdata(clear_paths.scat);
595 DATARRAY *scat1m_clear_dp = getdata(clear_paths.scat1m);
596
597 write_header(argc, argv, ccover, grefl, res);
598
599 if (!gen_spect_sky(tau_clear_dp, scat_clear_dp, scat1m_clear_dp,
600 irrad_clear_dp, ccover, sundir, grefl, res, outname, ddir,
601 dirnorm, difhor)) {
602 fprintf(stderr, "gen_spect_sky failed\n");
603 exit(1);
604 }
605
606 freedata(mie_dp);
607 freedata(tau_clear_dp);
608 freedata(scat_clear_dp);
609 freedata(irrad_clear_dp);
610 freedata(scat1m_clear_dp);
611
612 return 1;
613 }