| 1 |
// Main function for generating spectral sky |
| 2 |
// Cloudy sky computed as weight average of clear and cie overcast sky |
| 3 |
|
| 4 |
#include "copyright.h" |
| 5 |
#include "atmos.h" |
| 6 |
#include "resolu.h" |
| 7 |
#include "view.h" |
| 8 |
|
| 9 |
|
| 10 |
char *progname; |
| 11 |
|
| 12 |
const double ARCTIC_LAT = 67.; |
| 13 |
const double TROPIC_LAT = 23.; |
| 14 |
const int SUMMER_START = 4; |
| 15 |
const int SUMMER_END = 9; |
| 16 |
const double GNORM = 0.777778; |
| 17 |
|
| 18 |
const double D65EFF = 203.; /* standard illuminant D65 */ |
| 19 |
|
| 20 |
// Mean normalized relative daylight spectra where CCT = 6415K for overcast; |
| 21 |
const double D6415[NSSAMP] = {0.63231, 1.06171, 1.00779, 1.36423, 1.34133, |
| 22 |
1.27258, 1.26276, 1.26352, 1.22201, 1.13246, |
| 23 |
1.0434, 1.05547, 0.98212, 0.94445, 0.9722, |
| 24 |
0.82387, 0.87853, 0.82559, 0.75111, 0.78925}; |
| 25 |
|
| 26 |
static inline double wmean2(const double a, const double b, const double x) { |
| 27 |
return a * (1 - x) + b * x; |
| 28 |
} |
| 29 |
|
| 30 |
static inline double wmean(const double a, const double x, const double b, |
| 31 |
const double y) { |
| 32 |
return (a * x + b * y) / (a + b); |
| 33 |
} |
| 34 |
|
| 35 |
static double get_zenith_brightness(const double sundir[3]) { |
| 36 |
double zenithbr; |
| 37 |
if (sundir[2] < 0) { |
| 38 |
zenithbr = 0; |
| 39 |
} else { |
| 40 |
zenithbr = (8.6 * sundir[2] + .123) * 1000.0 / D65EFF; |
| 41 |
} |
| 42 |
return zenithbr; |
| 43 |
} |
| 44 |
|
| 45 |
// from gensky.c |
| 46 |
static double get_overcast_brightness(const double dz, const double zenithbr) { |
| 47 |
double groundbr = zenithbr * GNORM; |
| 48 |
return wmean(pow(dz + 1.01, 10), zenithbr * (1 + 2 * dz) / 3, |
| 49 |
pow(dz + 1.01, -10), groundbr); |
| 50 |
} |
| 51 |
|
| 52 |
static void write_rad_file(FILE *fp, const double *sun_radiance, |
| 53 |
const FVECT sundir, const char skyfile[PATH_MAX], |
| 54 |
const char grndfile[PATH_MAX]) { |
| 55 |
if (sundir[2] > 0) { |
| 56 |
fprintf(fp, "void spectrum sunrad\n0\n0\n22 380 780 "); |
| 57 |
for (int i = 0; i < NSSAMP; ++i) { |
| 58 |
fprintf(fp, "%.1f ", sun_radiance[i] * WVLSPAN); |
| 59 |
} |
| 60 |
fprintf(fp, "\n\nsunrad light solar\n0\n0\n3 1 1 1\n\n"); |
| 61 |
fprintf(fp, "solar source sun\n0\n0\n4 %f %f %f 0.533\n\n", sundir[0], |
| 62 |
sundir[1], sundir[2]); |
| 63 |
} |
| 64 |
fprintf(fp, |
| 65 |
"void specpict skyfunc\n8 noop %s fisheye.cal fish_u fish_v -rx 90 " |
| 66 |
"-mx\n0\n0\n\n", |
| 67 |
skyfile); |
| 68 |
fprintf(fp, "skyfunc glow sky_glow\n0\n0\n4 1 1 1 0\n\n"); |
| 69 |
fprintf(fp, "sky_glow source sky\n0\n0\n4 0 0 1 180\n\n"); |
| 70 |
|
| 71 |
fprintf(fp, |
| 72 |
"void specpict grndmap\n8 noop %s fisheye.cal fish_u fish_v -rx -90 " |
| 73 |
"-my\n0\n0\n\n", |
| 74 |
grndfile); |
| 75 |
fprintf(fp, "grndmap glow ground_glow\n0\n0\n4 1 1 1 0\n\n"); |
| 76 |
fprintf(fp, "ground_glow source ground_source\n0\n0\n4 0 0 -1 180\n\n"); |
| 77 |
} |
| 78 |
|
| 79 |
static void write_hsr_header(FILE *fp, RESOLU *res) { |
| 80 |
float wvsplit[4] = {380, 480, 588, |
| 81 |
780}; // RGB wavelength limits+partitions (nm) |
| 82 |
newheader("RADIANCE", fp); |
| 83 |
fputncomp(NSSAMP, fp); |
| 84 |
fputwlsplit(wvsplit, fp); |
| 85 |
fputformat(SPECFMT, fp); |
| 86 |
fputc('\n', fp); |
| 87 |
fputsresolu(res, fp); |
| 88 |
} |
| 89 |
|
| 90 |
int gen_spect_sky(DATARRAY *tau_clear, DATARRAY *scat_clear, |
| 91 |
DATARRAY *scat1m_clear, DATARRAY *irrad_clear, |
| 92 |
const double cloud_cover, const FVECT sundir, |
| 93 |
const double grefl, const int res, const char *outname) { |
| 94 |
|
| 95 |
char radfile[PATH_MAX]; |
| 96 |
char skyfile[PATH_MAX]; |
| 97 |
char grndfile[PATH_MAX]; |
| 98 |
if (!snprintf(radfile, sizeof(radfile), "%s.rad", outname)) { |
| 99 |
fprintf(stderr, "Error setting rad file name\n"); |
| 100 |
return 0; |
| 101 |
}; |
| 102 |
if (!snprintf(skyfile, sizeof(skyfile), "%s_sky.hsr", outname)) { |
| 103 |
fprintf(stderr, "Error setting sky file name\n"); |
| 104 |
return 0; |
| 105 |
}; |
| 106 |
if (!snprintf(grndfile, sizeof(grndfile), "%s_ground.hsr", outname)) { |
| 107 |
fprintf(stderr, "Error setting ground file name\n"); |
| 108 |
return 0; |
| 109 |
} |
| 110 |
RESOLU rs = {PIXSTANDARD, res, res}; |
| 111 |
FILE *skyfp = fopen(skyfile, "w"); |
| 112 |
FILE *grndfp = fopen(grndfile, "w"); |
| 113 |
write_hsr_header(grndfp, &rs); |
| 114 |
write_hsr_header(skyfp, &rs); |
| 115 |
VIEW skyview = {VT_ANG, {0., 0., 0.}, {0., 0., 1.}, {0., 1., 0.}, 1., |
| 116 |
180., 180., 0., 0., 0., |
| 117 |
0., {0., 0., 0.}, {0., 0., 0.}, 0., 0.}; |
| 118 |
VIEW grndview = { |
| 119 |
VT_ANG, {0., 0., 0.}, {0., 0., -1.}, {0., 1., 0.}, 1., 180., 180., 0., 0., |
| 120 |
0., 0., {0., 0., 0.}, {0., 0., 0.}, 0., 0.}; |
| 121 |
setview(&skyview); |
| 122 |
setview(&grndview); |
| 123 |
|
| 124 |
CNDX[3] = NSSAMP; |
| 125 |
|
| 126 |
FVECT view_point = {0, 0, ER}; |
| 127 |
const double radius = VLEN(view_point); |
| 128 |
const double sun_ct = fdot(view_point, sundir) / radius; |
| 129 |
for (unsigned int j = 0; j < res; ++j) { |
| 130 |
for (unsigned int i = 0; i < res; ++i) { |
| 131 |
RREAL loc[2]; |
| 132 |
FVECT rorg = {0}; |
| 133 |
FVECT rdir_sky = {0}; |
| 134 |
FVECT rdir_grnd = {0}; |
| 135 |
SCOLOR sky_radiance = {0}; |
| 136 |
SCOLOR ground_radiance = {0}; |
| 137 |
SCOLR sky_sclr = {0}; |
| 138 |
SCOLR ground_sclr = {0}; |
| 139 |
|
| 140 |
pix2loc(loc, &rs, i, j); |
| 141 |
viewray(rorg, rdir_sky, &skyview, loc[0], loc[1]); |
| 142 |
viewray(rorg, rdir_grnd, &grndview, loc[0], loc[1]); |
| 143 |
|
| 144 |
const double mu_sky = fdot(view_point, rdir_sky) / radius; |
| 145 |
const double nu_sky = fdot(rdir_sky, sundir); |
| 146 |
|
| 147 |
const double mu_grnd = fdot(view_point, rdir_grnd) / radius; |
| 148 |
const double nu_grnd = fdot(rdir_grnd, sundir); |
| 149 |
|
| 150 |
get_sky_radiance(scat_clear, scat1m_clear, radius, mu_sky, sun_ct, nu_sky, |
| 151 |
sky_radiance); |
| 152 |
get_ground_radiance(tau_clear, scat_clear, scat1m_clear, irrad_clear, |
| 153 |
view_point, rdir_grnd, radius, mu_grnd, sun_ct, |
| 154 |
nu_grnd, grefl, sundir, ground_radiance); |
| 155 |
|
| 156 |
for (int k = 0; k < NSSAMP; ++k) { |
| 157 |
sky_radiance[k] *= WVLSPAN; |
| 158 |
ground_radiance[k] *= WVLSPAN; |
| 159 |
} |
| 160 |
|
| 161 |
if (cloud_cover > 0) { |
| 162 |
double zenithbr = get_zenith_brightness(sundir); |
| 163 |
double grndbr = zenithbr * GNORM; |
| 164 |
double skybr = get_overcast_brightness(rdir_sky[2], zenithbr); |
| 165 |
for (int k = 0; k < NSSAMP; ++k) { |
| 166 |
sky_radiance[k] = |
| 167 |
wmean2(sky_radiance[k], skybr * D6415[k], cloud_cover); |
| 168 |
ground_radiance[k] = |
| 169 |
wmean2(ground_radiance[k], grndbr * D6415[k], cloud_cover); |
| 170 |
} |
| 171 |
} |
| 172 |
|
| 173 |
scolor2scolr(sky_sclr, sky_radiance, 20); |
| 174 |
putbinary(sky_sclr, LSCOLR, 1, skyfp); |
| 175 |
|
| 176 |
scolor2scolr(ground_sclr, ground_radiance, 20); |
| 177 |
putbinary(ground_sclr, LSCOLR, 1, grndfp); |
| 178 |
} |
| 179 |
} |
| 180 |
fclose(skyfp); |
| 181 |
fclose(grndfp); |
| 182 |
|
| 183 |
// Get solar radiance |
| 184 |
double sun_radiance[NSSAMP] = {0}; |
| 185 |
get_solar_radiance(tau_clear, scat_clear, scat1m_clear, sundir, radius, |
| 186 |
sun_ct, sun_radiance); |
| 187 |
if (cloud_cover > 0) { |
| 188 |
double zenithbr = get_zenith_brightness(sundir); |
| 189 |
double skybr = get_overcast_brightness(sundir[2], zenithbr); |
| 190 |
for (int i = 0; i < NSSAMP; ++i) { |
| 191 |
sun_radiance[i] = |
| 192 |
wmean2(sun_radiance[i], D6415[i] * skybr / WVLSPAN, cloud_cover); |
| 193 |
} |
| 194 |
} |
| 195 |
|
| 196 |
FILE *rfp = fopen(radfile, "w"); |
| 197 |
write_rad_file(rfp, sun_radiance, sundir, skyfile, grndfile); |
| 198 |
fclose(rfp); |
| 199 |
return 1; |
| 200 |
} |
| 201 |
|
| 202 |
static DpPaths get_dppaths(const double aod, const char *tag) { |
| 203 |
DpPaths paths; |
| 204 |
|
| 205 |
snprintf(paths.tau, PATH_MAX, "tau_%s_%.2f.dat", tag, aod); |
| 206 |
snprintf(paths.scat, PATH_MAX, "scat_%s_%.2f.dat", tag, aod); |
| 207 |
snprintf(paths.scat1m, PATH_MAX, "scat1m_%s_%.2f.dat", tag, aod); |
| 208 |
snprintf(paths.irrad, PATH_MAX, "irrad_%s_%.2f.dat", tag, aod); |
| 209 |
|
| 210 |
return paths; |
| 211 |
} |
| 212 |
|
| 213 |
static void set_rayleigh_density_profile(Atmosphere *atmos, char *tag, const int is_summer, |
| 214 |
const double s_latitude) { |
| 215 |
// Set rayleigh density profile |
| 216 |
if (fabs(s_latitude*180.0 / PI) > ARCTIC_LAT) { |
| 217 |
tag[0] = 's'; |
| 218 |
if (is_summer) { |
| 219 |
tag[1] = 's'; |
| 220 |
atmos->rayleigh_density.layers[0].exp_scale = -1.0 / HR_SS; |
| 221 |
atmos->beta_r0 = BR0_SS; |
| 222 |
} else { |
| 223 |
tag[1] = 'w'; |
| 224 |
atmos->rayleigh_density.layers[0].exp_scale = -1.0 / HR_SW; |
| 225 |
atmos->beta_r0 = BR0_SW; |
| 226 |
} |
| 227 |
} else if (fabs(s_latitude*180.0/PI) > TROPIC_LAT) { |
| 228 |
tag[0] = 'm'; |
| 229 |
if (is_summer) { |
| 230 |
tag[1] = 's'; |
| 231 |
atmos->rayleigh_density.layers[0].exp_scale = -1.0 / HR_MS; |
| 232 |
atmos->beta_r0 = BR0_MS; |
| 233 |
} else { |
| 234 |
tag[1] = 'w'; |
| 235 |
atmos->rayleigh_density.layers[0].exp_scale = -1.0 / HR_MW; |
| 236 |
atmos->beta_r0 = BR0_MW; |
| 237 |
} |
| 238 |
} else { |
| 239 |
tag[0] = 't'; |
| 240 |
tag[1] = 'r'; |
| 241 |
atmos->rayleigh_density.layers[0].exp_scale = -1.0 / HR_T; |
| 242 |
atmos->beta_r0 = BR0_T; |
| 243 |
} |
| 244 |
tag[2] = '\0'; |
| 245 |
} |
| 246 |
|
| 247 |
static Atmosphere init_atmos(const double aod, const double grefl) { |
| 248 |
Atmosphere atmos = { |
| 249 |
.ozone_density = {.layers = |
| 250 |
{ |
| 251 |
{.width = 25000.0, |
| 252 |
.exp_term = 0.0, |
| 253 |
.exp_scale = 0.0, |
| 254 |
.linear_term = 1.0 / 15000.0, |
| 255 |
.constant_term = -2.0 / 3.0}, |
| 256 |
{.width = AH, |
| 257 |
.exp_term = 0.0, |
| 258 |
.exp_scale = 0.0, |
| 259 |
.linear_term = -1.0 / 15000.0, |
| 260 |
.constant_term = 8.0 / 3.0}, |
| 261 |
}}, |
| 262 |
.rayleigh_density = {.layers = |
| 263 |
{ |
| 264 |
{.width = AH, |
| 265 |
.exp_term = 1.0, |
| 266 |
.exp_scale = -1.0 / HR_MS, |
| 267 |
.linear_term = 0.0, |
| 268 |
.constant_term = 0.0}, |
| 269 |
}}, |
| 270 |
.beta_r0 = BR0_MS, |
| 271 |
.beta_scale = aod / AOD0_CA, |
| 272 |
.beta_m = NULL, |
| 273 |
.grefl = grefl |
| 274 |
}; |
| 275 |
return atmos; |
| 276 |
} |
| 277 |
|
| 278 |
int main(int argc, char *argv[]) { |
| 279 |
progname = argv[0]; |
| 280 |
int month, day; |
| 281 |
double hour; |
| 282 |
FVECT sundir; |
| 283 |
int num_threads = 1; |
| 284 |
int sorder = 4; |
| 285 |
int year = 0; |
| 286 |
int tsolar = 0; |
| 287 |
double grefl = 0.2; |
| 288 |
double ccover = 0.0; |
| 289 |
int res = 128; |
| 290 |
double aod = AOD0_CA; |
| 291 |
char *outname = "out"; |
| 292 |
char *mie_path = getpath("mie_ca.dat", getrlibpath(), R_OK); |
| 293 |
char lstag[3]; |
| 294 |
|
| 295 |
if (argc < 4) { |
| 296 |
fprintf(stderr, "Usage: %s month day hour -y year -a lat -o lon -m tz -d aod -r res -n nproc -c ccover -l mie -g grefl -f outpath\n", |
| 297 |
argv[0]); |
| 298 |
return 0; |
| 299 |
} |
| 300 |
|
| 301 |
month = atoi(argv[1]); |
| 302 |
day = atoi(argv[2]); |
| 303 |
hour = atof(argv[3]); |
| 304 |
|
| 305 |
if (!compute_sundir(year, month, day, hour, tsolar, sundir)) { |
| 306 |
fprintf(stderr, "Cannot compute solar angle\n"); |
| 307 |
exit(1); |
| 308 |
} |
| 309 |
|
| 310 |
for (int i = 4; i < argc; i++) { |
| 311 |
if (argv[i][0] == '-') { |
| 312 |
switch (argv[i][1]) { |
| 313 |
case 'a': |
| 314 |
s_latitude = atof(argv[++i]) * (PI / 180.0); |
| 315 |
break; |
| 316 |
case 'g': |
| 317 |
grefl = atof(argv[++i]); |
| 318 |
break; |
| 319 |
case 'c': |
| 320 |
ccover = atof(argv[++i]); |
| 321 |
break; |
| 322 |
case 'd': |
| 323 |
aod = atof(argv[++i]); |
| 324 |
break; |
| 325 |
case 'i': |
| 326 |
sorder = atoi(argv[++i]); |
| 327 |
break; |
| 328 |
case 'l': |
| 329 |
mie_path = argv[++i]; |
| 330 |
break; |
| 331 |
case 'm': |
| 332 |
s_meridian = atof(argv[++i]) * (PI / 180.0); |
| 333 |
break; |
| 334 |
case 'o': |
| 335 |
s_longitude = atof(argv[++i]) * (PI / 180.0); |
| 336 |
break; |
| 337 |
case 'n': |
| 338 |
num_threads = atoi(argv[++i]); |
| 339 |
break; |
| 340 |
case 'y': |
| 341 |
year = atoi(argv[++i]); |
| 342 |
break; |
| 343 |
case 'f': |
| 344 |
outname = argv[++i]; |
| 345 |
break; |
| 346 |
case 'r': |
| 347 |
res = atoi(argv[++i]); |
| 348 |
break; |
| 349 |
default: |
| 350 |
fprintf(stderr, "Unknown option %s\n", argv[i]); |
| 351 |
exit(1); |
| 352 |
} |
| 353 |
} |
| 354 |
} |
| 355 |
|
| 356 |
Atmosphere clear_atmos = init_atmos(aod, grefl); |
| 357 |
|
| 358 |
int is_summer = (month >= SUMMER_START && month <= SUMMER_END); |
| 359 |
if (s_latitude < 0) { |
| 360 |
is_summer = !is_summer; |
| 361 |
} |
| 362 |
set_rayleigh_density_profile(&clear_atmos, lstag, is_summer, s_latitude); |
| 363 |
|
| 364 |
// Load mie density data |
| 365 |
DATARRAY *mie_dp = getdata(mie_path); |
| 366 |
if (mie_dp == NULL) { |
| 367 |
fprintf(stderr, "Error reading mie data\n"); |
| 368 |
return 0; |
| 369 |
} |
| 370 |
clear_atmos.beta_m = mie_dp; |
| 371 |
|
| 372 |
DpPaths clear_paths = get_dppaths(aod, lstag); |
| 373 |
|
| 374 |
if (getpath(clear_paths.tau, ".", R_OK) == NULL || |
| 375 |
getpath(clear_paths.scat, ".", R_OK) == NULL || |
| 376 |
getpath(clear_paths.scat1m, ".", R_OK) == NULL || |
| 377 |
getpath(clear_paths.irrad, ".", R_OK) == NULL) { |
| 378 |
printf("# Precomputing...\n"); |
| 379 |
if (!precompute(sorder, clear_paths, &clear_atmos, num_threads)) { |
| 380 |
fprintf(stderr, "Precompute failed\n"); |
| 381 |
return 0; |
| 382 |
} |
| 383 |
} |
| 384 |
|
| 385 |
DATARRAY *tau_clear_dp = getdata(clear_paths.tau); |
| 386 |
DATARRAY *irrad_clear_dp = getdata(clear_paths.irrad); |
| 387 |
DATARRAY *scat_clear_dp = getdata(clear_paths.scat); |
| 388 |
DATARRAY *scat1m_clear_dp = getdata(clear_paths.scat1m); |
| 389 |
|
| 390 |
if (!gen_spect_sky(tau_clear_dp, scat_clear_dp, scat1m_clear_dp, |
| 391 |
irrad_clear_dp, ccover, sundir, grefl, res, outname)) { |
| 392 |
fprintf(stderr, "gen_spect_sky failed\n"); |
| 393 |
exit(1); |
| 394 |
} |
| 395 |
|
| 396 |
freedata(mie_dp); |
| 397 |
freedata(tau_clear_dp); |
| 398 |
freedata(scat_clear_dp); |
| 399 |
freedata(irrad_clear_dp); |
| 400 |
freedata(scat1m_clear_dp); |
| 401 |
|
| 402 |
return 1; |
| 403 |
} |
