--- ray/src/gen/gensky.c 1989/02/02 11:16:29 1.1 +++ ray/src/gen/gensky.c 2003/02/22 02:07:23 2.20 @@ -1,9 +1,6 @@ -/* Copyright (c) 1986 Regents of the University of California */ - #ifndef lint -static char SCCSid[] = "$SunId$ LBL"; +static const char RCSid[] = "$Id: gensky.c,v 2.20 2003/02/22 02:07:23 greg Exp $"; #endif - /* * gensky.c - program to generate sky functions. * Our zenith is along the Z-axis, the X-axis @@ -15,35 +12,80 @@ static char SCCSid[] = "$SunId$ LBL"; #include +#include + +#include + #include +#include -extern char *strcpy(), *strcat(), *malloc(); -extern double stadj(), sdec(), sazi(), salt(); +#include "color.h" -#define PI 3.141592654 +extern double stadj(), sdec(), sazi(), salt(), tz2mer(); +#ifndef PI +#define PI 3.14159265358979323846 +#endif + #define DOT(v1,v2) (v1[0]*v2[0]+v1[1]*v2[1]+v1[2]*v2[2]) +#define S_CLEAR 1 +#define S_OVER 2 +#define S_UNIF 3 +#define S_INTER 4 + +#define overcast (skytype==S_OVER|skytype==S_UNIF) + double normsc(); /* sun calculation constants */ extern double s_latitude; extern double s_longitude; extern double s_meridian; + +#undef toupper +#define toupper(c) ((c) & ~0x20) /* ASCII trick to convert case */ + + /* European and North American zones */ +struct { + char zname[8]; /* time zone name (all caps) */ + float zmer; /* standard meridian */ +} tzone[] = { + "YST", 135, "YDT", 120, + "PST", 120, "PDT", 105, + "MST", 105, "MDT", 90, + "CST", 90, "CDT", 75, + "EST", 75, "EDT", 60, + "AST", 60, "ADT", 45, + "NST", 52.5, "NDT", 37.5, + "GMT", 0, "BST", -15, + "CET", -15, "CEST", -30, + "EET", -30, "EEST", -45, + "AST", -45, "ADT", -60, + "GST", -60, "GDT", -75, + "IST", -82.5, "IDT", -97.5, + "JST", -135, "NDT", -150, + "NZST", -180, "NZDT", -195, + "", 0 +}; /* required values */ -int month, day; -double hour; +int month, day; /* date */ +double hour; /* time */ +int tsolar; /* 0=standard, 1=solar */ +double altitude, azimuth; /* or solar angles */ /* default values */ -int cloudy = 0; +int skytype = S_CLEAR; /* sky type */ int dosun = 1; -double zenithbr = -1.0; +double zenithbr = 0.0; +int u_zenith = 0; /* -1=irradiance, 1=radiance */ double turbidity = 2.75; double gprefl = 0.2; /* computed values */ double sundir[3]; double groundbr; double F2; -double solarbr; +double solarbr = 0.0; +int u_solar = 0; /* -1=irradiance, 1=radiance */ char *progname; char errmsg[128]; @@ -53,7 +95,6 @@ main(argc, argv) int argc; char *argv[]; { - extern double atof(); int i; progname = argv[0]; @@ -63,24 +104,47 @@ char *argv[]; } if (argc < 4) userror("arg count"); - month = atoi(argv[1]); - day = atoi(argv[2]); - hour = atof(argv[3]); + if (!strcmp(argv[1], "-ang")) { + altitude = atof(argv[2]) * (PI/180); + azimuth = atof(argv[3]) * (PI/180); + month = 0; + } else { + month = atoi(argv[1]); + if (month < 1 || month > 12) + userror("bad month"); + day = atoi(argv[2]); + if (day < 1 || day > 31) + userror("bad day"); + cvthour(argv[3]); + } for (i = 4; i < argc; i++) if (argv[i][0] == '-' || argv[i][0] == '+') switch (argv[i][1]) { case 's': - cloudy = 0; + skytype = S_CLEAR; dosun = argv[i][0] == '+'; break; + case 'r': + case 'R': + u_solar = argv[i][1]=='R' ? -1 : 1; + solarbr = atof(argv[++i]); + break; case 'c': - cloudy = 1; - dosun = 0; + skytype = S_OVER; break; + case 'u': + skytype = S_UNIF; + break; + case 'i': + skytype = S_INTER; + dosun = argv[i][0] == '+'; + break; case 't': turbidity = atof(argv[++i]); break; case 'b': + case 'B': + u_zenith = argv[i][1]=='B' ? -1 : 1; zenithbr = atof(argv[++i]); break; case 'g': @@ -102,91 +166,150 @@ char *argv[]; else userror("bad option"); + if (fabs(s_meridian-s_longitude) > 45*PI/180) + fprintf(stderr, + "%s: warning: %.1f hours btwn. standard meridian and longitude\n", + progname, (s_longitude-s_meridian)*12/PI); + printhead(argc, argv); computesky(); printsky(); + + exit(0); } computesky() /* compute sky parameters */ { - int jd; - double sd, st; - double altitude, azimuth; + double normfactor; /* compute solar direction */ - jd = jdate(month, day); /* Julian date */ - sd = sdec(jd); /* solar declination */ - st = hour + stadj(jd); /* solar time */ - altitude = salt(sd, st); - azimuth = sazi(sd, st); + if (month) { /* from date and time */ + int jd; + double sd, st; + + jd = jdate(month, day); /* Julian date */ + sd = sdec(jd); /* solar declination */ + if (tsolar) /* solar time */ + st = hour; + else + st = hour + stadj(jd); + altitude = salt(sd, st); + azimuth = sazi(sd, st); + printf("# Local solar time: %.2f\n", st); + printf("# Solar altitude and azimuth: %.1f %.1f\n", + 180./PI*altitude, 180./PI*azimuth); + } + if (!overcast && altitude > 87.*PI/180.) { + fprintf(stderr, +"%s: warning - sun too close to zenith, reducing altitude to 87 degrees\n", + progname); + printf( +"# warning - sun too close to zenith, reducing altitude to 87 degrees\n"); + altitude = 87.*PI/180.; + } sundir[0] = -sin(azimuth)*cos(altitude); sundir[1] = -cos(azimuth)*cos(altitude); sundir[2] = sin(altitude); + /* Compute normalization factor */ + switch (skytype) { + case S_UNIF: + normfactor = 1.0; + break; + case S_OVER: + normfactor = 0.777778; + break; + case S_CLEAR: + F2 = 0.274*(0.91 + 10.0*exp(-3.0*(PI/2.0-altitude)) + + 0.45*sundir[2]*sundir[2]); + normfactor = normsc()/F2/PI; + break; + case S_INTER: + F2 = (2.739 + .9891*sin(.3119+2.6*altitude)) * + exp(-(PI/2.0-altitude)*(.4441+1.48*altitude)); + normfactor = normsc()/F2/PI; + break; + } /* Compute zenith brightness */ - if (zenithbr <= 0.0) - if (cloudy) { + if (u_zenith == -1) + zenithbr /= normfactor*PI; + else if (u_zenith == 0) { + if (overcast) zenithbr = 8.6*sundir[2] + .123; - zenithbr *= 1000.0/683.0; - } else { + else zenithbr = (1.376*turbidity-1.81)*tan(altitude)+0.38; - zenithbr *= 1000.0/683.0; - } - /* Compute horizontal radiance */ - if (cloudy) { - groundbr = zenithbr*0.777778; - printf("# Ground ambient level: %f\n", groundbr); - } else { - F2 = 0.274*(0.91 + 10.0*exp(-3.0*(PI/2.0-altitude)) + - 0.45*sundir[2]*sundir[2]); - groundbr = zenithbr*normsc(PI/2.0-altitude)/F2/PI; - printf("# Ground ambient level: %f\n", groundbr); - if (sundir[2] > 0.0) { - if (sundir[2] > .16) - solarbr = 2.47e6 - 3.15e5/sundir[2]; - else - solarbr = 5e5; - groundbr += solarbr*6e-5*sundir[2]/PI; - } else - dosun = 0; + if (skytype == S_INTER) + zenithbr = (zenithbr + 8.6*sundir[2] + .123)/2.0; + if (zenithbr < 0.0) + zenithbr = 0.0; + else + zenithbr *= 1000.0/SKYEFFICACY; } + /* Compute horizontal radiance */ + groundbr = zenithbr*normfactor; + printf("# Ground ambient level: %.1f\n", groundbr); + if (!overcast && sundir[2] > 0.0 && (!u_solar || solarbr > 0.0)) { + if (u_solar == -1) + solarbr /= 6e-5*sundir[2]; + else if (u_solar == 0) { + solarbr = 1.5e9/SUNEFFICACY * + (1.147 - .147/(sundir[2]>.16?sundir[2]:.16)); + if (skytype == S_INTER) + solarbr *= 0.15; /* fudge factor! */ + } + groundbr += 6e-5/PI*solarbr*sundir[2]; + } else + dosun = 0; groundbr *= gprefl; } printsky() /* print out sky */ { - register int i; - if (dosun) { printf("\nvoid light solar\n"); printf("0\n0\n"); - printf("3 %f %f %f\n", solarbr, solarbr, solarbr); + printf("3 %.2e %.2e %.2e\n", solarbr, solarbr, solarbr); printf("\nsolar source sun\n"); printf("0\n0\n"); printf("4 %f %f %f 0.5\n", sundir[0], sundir[1], sundir[2]); } printf("\nvoid brightfunc skyfunc\n"); - printf("2 skybright skybright.cal\n"); + printf("2 skybr skybright.cal\n"); printf("0\n"); - if (cloudy) - printf("3 1 %f %f\n", zenithbr, groundbr); + if (overcast) + printf("3 %d %.2e %.2e\n", skytype, zenithbr, groundbr); else - printf("7 -1 %f %f %f %f %f %f\n", zenithbr, groundbr, F2, + printf("7 %d %.2e %.2e %.2e %f %f %f\n", + skytype, zenithbr, groundbr, F2, sundir[0], sundir[1], sundir[2]); } printdefaults() /* print default values */ { - if (cloudy) + switch (skytype) { + case S_OVER: printf("-c\t\t\t\t# Cloudy sky\n"); - else if (dosun) - printf("+s\t\t\t\t# Sunny sky with sun\n"); - else - printf("-s\t\t\t\t# Sunny sky without sun\n"); + break; + case S_UNIF: + printf("-u\t\t\t\t# Uniform cloudy sky\n"); + break; + case S_INTER: + if (dosun) + printf("+i\t\t\t\t# Intermediate sky with sun\n"); + else + printf("-i\t\t\t\t# Intermediate sky without sun\n"); + break; + case S_CLEAR: + if (dosun) + printf("+s\t\t\t\t# Sunny sky with sun\n"); + else + printf("-s\t\t\t\t# Sunny sky without sun\n"); + break; + } printf("-g %f\t\t\t# Ground plane reflectance\n", gprefl); if (zenithbr > 0.0) printf("-b %f\t\t\t# Zenith radiance (watts/ster/m2\n", zenithbr); @@ -204,26 +327,73 @@ char *msg; if (msg != NULL) fprintf(stderr, "%s: Use error - %s\n", progname, msg); fprintf(stderr, "Usage: %s month day hour [options]\n", progname); + fprintf(stderr, " Or: %s -ang altitude azimuth [options]\n", progname); fprintf(stderr, " Or: %s -defaults\n", progname); exit(1); } double -normsc(theta) /* compute normalization factor (E0*F2/L0) */ -double theta; +normsc() /* compute normalization factor (E0*F2/L0) */ { - static double nf[5] = {2.766521, 0.547665, - -0.369832, 0.009237, 0.059229}; + static double nfc[2][5] = { + /* clear sky approx. */ + {2.766521, 0.547665, -0.369832, 0.009237, 0.059229}, + /* intermediate sky approx. */ + {3.5556, -2.7152, -1.3081, 1.0660, 0.60227}, + }; + register double *nf; double x, nsc; register int i; /* polynomial approximation */ - x = (theta - PI/4.0)/(PI/4.0); - nsc = nf[4]; - for (i = 3; i >= 0; i--) + nf = nfc[skytype==S_INTER]; + x = (altitude - PI/4.0)/(PI/4.0); + nsc = nf[i=4]; + while (i--) nsc = nsc*x + nf[i]; return(nsc); +} + + +cvthour(hs) /* convert hour string */ +char *hs; +{ + register char *cp = hs; + register int i, j; + + if (tsolar = *cp == '+') cp++; /* solar time? */ + while (isdigit(*cp)) cp++; + if (*cp == ':') + hour = atoi(hs) + atoi(++cp)/60.0; + else { + hour = atof(hs); + if (*cp == '.') cp++; + } + while (isdigit(*cp)) cp++; + if (!*cp) + return; + if (tsolar || !isalpha(*cp)) { + fprintf(stderr, "%s: bad time format: %s\n", progname, hs); + exit(1); + } + i = 0; + do { + for (j = 0; cp[j]; j++) + if (toupper(cp[j]) != tzone[i].zname[j]) + break; + if (!cp[j] && !tzone[i].zname[j]) { + s_meridian = tzone[i].zmer * (PI/180); + return; + } + } while (tzone[i++].zname[0]); + + fprintf(stderr, "%s: unknown time zone: %s\n", progname, cp); + fprintf(stderr, "Known time zones:\n\t%s", tzone[0].zname); + for (i = 1; tzone[i].zname[0]; i++) + fprintf(stderr, " %s", tzone[i].zname); + putc('\n', stderr); + exit(1); }