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root/radiance/ray/src/util/rsensor.c
Revision: 2.6
Committed: Sat Dec 13 00:44:05 2008 UTC (15 years, 4 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.5: +27 -13 lines
Log Message:
Improved sampling method very slightly

File Contents

# User Rev Content
1 greg 2.1 #ifndef lint
2 greg 2.6 static const char RCSid[] = "$Id: rsensor.c,v 2.5 2008/04/11 22:06:04 greg Exp $";
3 greg 2.1 #endif
4    
5     /*
6     * Compute sensor signal based on spatial sensitivity.
7     *
8     * Created Feb 2008 for Architectural Energy Corp.
9     */
10    
11     #include "ray.h"
12     #include "source.h"
13     #include "view.h"
14     #include "random.h"
15    
16     #define DEGREE (PI/180.)
17    
18     #define MAXNT 180 /* maximum number of theta divisions */
19     #define MAXNP 360 /* maximum number of phi divisions */
20    
21     extern char *progname; /* global argv[0] */
22     extern int nowarn; /* don't report warnings? */
23    
24     /* current sensor's perspective */
25 greg 2.5 VIEW ourview = {VT_ANG,{0.,0.,0.},{0.,0.,1.},{1.,0.,0.},
26     1.,180.,180.,0.,0.,0.,0.,
27     {0.,0.,0.},{0.,0.,0.},0.,0.};
28 greg 2.1
29     unsigned long nsamps = 10000; /* desired number of initial samples */
30     unsigned long nssamps = 9000; /* number of super-samples */
31 greg 2.2 int ndsamps = 32; /* number of direct samples */
32 greg 2.1 int nprocs = 1; /* number of rendering processes */
33    
34     float *sensor = NULL; /* current sensor data */
35     int sntp[2]; /* number of sensor theta and phi angles */
36     float maxtheta; /* maximum theta value for this sensor */
37     float tvals[MAXNT+1]; /* theta values (1-D table of 1-cos(t)) */
38     float *pvals = NULL; /* phi values (2-D table in radians) */
39     int ntheta = 0; /* polar angle divisions */
40     int nphi = 0; /* azimuthal angle divisions */
41     double gscale = 1.; /* global scaling value */
42    
43 greg 2.2 #define s_theta(t) sensor[(t+1)*(sntp[1]+1)]
44     #define s_phi(p) sensor[(p)+1]
45     #define s_val(t,p) sensor[(p)+1+(t+1)*(sntp[1]+1)]
46    
47 greg 2.1 static void comp_sensor(char *sfile);
48    
49     static void
50 greg 2.3 over_options() /* overriding options */
51 greg 2.1 {
52 greg 2.3 directvis = (ndsamps <= 0);
53     do_irrad = 0;
54     }
55    
56     static void
57     print_defaults() /* print out default parameters */
58     {
59     over_options();
60 greg 2.1 printf("-n %-9d\t\t\t# number of processes\n", nprocs);
61     printf("-rd %-9ld\t\t\t# ray directions\n", nsamps);
62     /* printf("-rs %-9ld\t\t\t# ray super-samples\n", nssamps); */
63     printf("-dn %-9d\t\t\t# direct number of samples\n", ndsamps);
64     printf("-vp %f %f %f\t# view point\n",
65     ourview.vp[0], ourview.vp[1], ourview.vp[2]);
66     printf("-vd %f %f %f\t# view direction\n",
67     ourview.vdir[0], ourview.vdir[1], ourview.vdir[2]);
68     printf("-vu %f %f %f\t# view up\n",
69     ourview.vup[0], ourview.vup[1], ourview.vup[2]);
70     printf("-vo %f\t\t\t# view fore clipping distance\n", ourview.vfore);
71     print_rdefaults();
72     }
73    
74     int
75     main(
76     int argc,
77     char *argv[]
78     )
79     {
80     int doheader = 1;
81 greg 2.3 int optwarn = 0;
82 greg 2.1 int i, rval;
83    
84     progname = argv[0];
85     /* set up rendering defaults */
86 greg 2.2 rand_samp = 1;
87 greg 2.6 dstrsrc = 0.65;
88 greg 2.2 srcsizerat = 0.1;
89 greg 2.1 directrelay = 3;
90     ambounce = 1;
91 greg 2.2 maxdepth = -10;
92 greg 2.1 /* get options from command line */
93 greg 2.3 for (i = 1; i < argc; i++) {
94 greg 2.1 while ((rval = expandarg(&argc, &argv, i)) > 0)
95     ;
96     if (rval < 0) {
97     sprintf(errmsg, "cannot expand '%s'", argv[i]);
98     error(SYSTEM, errmsg);
99     }
100 greg 2.3 if (argv[i][0] != '-') {
101     if (i >= argc-1)
102     break; /* final octree argument */
103 greg 2.1 if (!ray_pnprocs) {
104 greg 2.3 over_options();
105 greg 2.1 if (doheader) { /* print header */
106 greg 2.6 newheader("RADIANCE", stdout);
107 greg 2.1 printargs(argc, argv, stdout);
108     fputformat("ascii", stdout);
109     putchar('\n');
110     }
111     /* start process(es) */
112     ray_pinit(argv[argc-1], nprocs);
113     }
114 greg 2.3 comp_sensor(argv[i]); /* process a sensor file */
115 greg 2.1 continue;
116     }
117     if (argv[i][1] == 'r') { /* sampling options */
118     if (argv[i][2] == 'd')
119     nsamps = atol(argv[++i]);
120     else if (argv[i][2] == 's')
121     nssamps = atol(argv[++i]);
122     else {
123     sprintf(errmsg, "bad option at '%s'", argv[i]);
124     error(USER, errmsg);
125     }
126     continue;
127     }
128     /* direct component samples */
129     if (argv[i][1] == 'd' && argv[i][2] == 'n') {
130     ndsamps = atoi(argv[++i]);
131     continue;
132     }
133     if (argv[i][1] == 'v') { /* next sensor view */
134     if (argv[i][2] == 'f') {
135     rval = viewfile(argv[++i], &ourview, NULL);
136     if (rval < 0) {
137     sprintf(errmsg,
138     "cannot open view file \"%s\"",
139     argv[i]);
140     error(SYSTEM, errmsg);
141     } else if (rval == 0) {
142     sprintf(errmsg,
143     "bad view file \"%s\"",
144     argv[i]);
145     error(USER, errmsg);
146     }
147     continue;
148     }
149     rval = getviewopt(&ourview, argc-i, argv+i);
150     if (rval >= 0) {
151     i += rval;
152     continue;
153     }
154     sprintf(errmsg, "bad view option at '%s'", argv[i]);
155     error(USER, errmsg);
156     }
157 greg 2.3 if (!strcmp(argv[i], "-w")) { /* toggle warnings */
158     nowarn = !nowarn;
159 greg 2.1 continue;
160     }
161     if (ray_pnprocs) {
162 greg 2.3 if (!optwarn++)
163     error(WARNING,
164 greg 2.1 "rendering options should appear before first sensor");
165     } else if (!strcmp(argv[i], "-defaults")) {
166     print_defaults();
167     return(0);
168     }
169     if (argv[i][1] == 'h') { /* header toggle */
170     doheader = !doheader;
171     continue;
172     }
173     if (!strcmp(argv[i], "-n")) { /* number of processes */
174     nprocs = atoi(argv[++i]);
175     if (nprocs <= 0)
176     error(USER, "illegal number of processes");
177     continue;
178     }
179     rval = getrenderopt(argc-i, argv+i);
180     if (rval < 0) {
181     sprintf(errmsg, "bad render option at '%s'", argv[i]);
182     error(USER, errmsg);
183     }
184     i += rval;
185     }
186 greg 2.3 if (!ray_pnprocs)
187     error(USER, i<argc ? "missing sensor file" : "missing octree");
188 greg 2.1 quit(0);
189     }
190    
191     /* Load sensor sensitivities (first row and column are angles) */
192     static float *
193     load_sensor(
194     int ntp[2],
195     char *sfile
196     )
197     {
198     char linebuf[8192];
199     int nelem = 1000;
200     float *sarr = (float *)malloc(sizeof(float)*nelem);
201     FILE *fp;
202     char *cp;
203     int i;
204    
205     fp = frlibopen(sfile);
206     if (fp == NULL) {
207     sprintf(errmsg, "cannot open sensor file '%s'", sfile);
208     error(SYSTEM, errmsg);
209     }
210     fgets(linebuf, sizeof(linebuf), fp);
211     if (!strncmp(linebuf, "Elevation ", 10))
212     fgets(linebuf, sizeof(linebuf), fp);
213     /* get phi values */
214     sarr[0] = .0f;
215     if (strncmp(linebuf, "degrees", 7)) {
216     sprintf(errmsg, "Missing 'degrees' in sensor file '%s'", sfile);
217     error(USER, errmsg);
218     }
219     cp = sskip(linebuf);
220     ntp[1] = 0;
221     for ( ; ; ) {
222     sarr[ntp[1]+1] = atof(cp);
223     cp = fskip(cp);
224     if (cp == NULL)
225     break;
226     ++ntp[1];
227     }
228     ntp[0] = 0; /* get thetas + data */
229     while (fgets(linebuf, sizeof(linebuf), fp) != NULL) {
230     ++ntp[0];
231     if ((ntp[0]+1)*(ntp[1]+1) > nelem) {
232     nelem += (nelem>>2) + ntp[1];
233     sarr = (float *)realloc((void *)sarr,
234     sizeof(float)*nelem);
235     if (sarr == NULL)
236     error(SYSTEM, "out of memory in load_sensor()");
237     }
238     cp = linebuf;
239     i = ntp[0]*(ntp[1]+1);
240     for ( ; ; ) {
241     sarr[i] = atof(cp);
242     cp = fskip(cp);
243     if (cp == NULL)
244     break;
245     ++i;
246     }
247     if (i == ntp[0]*(ntp[1]+1))
248     break;
249     if (i != (ntp[0]+1)*(ntp[1]+1)) {
250     sprintf(errmsg,
251     "bad column count near line %d in sensor file '%s'",
252     ntp[0]+1, sfile);
253     error(USER, errmsg);
254     }
255     }
256     nelem = i;
257     fclose(fp);
258     errmsg[0] = '\0'; /* sanity checks */
259     if (ntp[0] <= 0)
260     sprintf(errmsg, "no data in sensor file '%s'", sfile);
261     else if (fabs(sarr[ntp[1]+1]) > FTINY)
262     sprintf(errmsg, "minimum theta must be 0 in sensor file '%s'",
263     sfile);
264     else if (fabs(sarr[1]) > FTINY)
265     sprintf(errmsg, "minimum phi must be 0 in sensor file '%s'",
266     sfile);
267     else if (sarr[ntp[1]] <= FTINY)
268     sprintf(errmsg,
269     "maximum phi must be positive in sensor file '%s'",
270     sfile);
271     else if (sarr[ntp[0]*(ntp[1]+1)] <= FTINY)
272     sprintf(errmsg,
273     "maximum theta must be positive in sensor file '%s'",
274     sfile);
275     if (errmsg[0])
276     error(USER, errmsg);
277     return((float *)realloc((void *)sarr, sizeof(float)*nelem));
278     }
279    
280     /* Initialize probability table */
281     static void
282     init_ptable(
283     char *sfile
284     )
285     {
286     int samptot = nsamps;
287     float *rowp, *rowp1;
288     double rowsum[MAXNT], rowomega[MAXNT];
289     double thdiv[MAXNT+1], phdiv[MAXNP+1];
290     double tsize, psize;
291     double prob, frac, frac1;
292     int i, j, t, p;
293     /* free old table */
294     if (sensor != NULL)
295     free((void *)sensor);
296     if (pvals != NULL)
297     free((void *)pvals);
298     if (sfile == NULL || !*sfile) {
299 greg 2.2 sensor = NULL;
300     sntp[0] = sntp[1] = 0;
301 greg 2.1 pvals = NULL;
302     ntheta = nphi = 0;
303     return;
304     }
305     /* load sensor table */
306     sensor = load_sensor(sntp, sfile);
307     if (sntp[0] > MAXNT) {
308     sprintf(errmsg, "Too many theta rows in sensor file '%s'",
309     sfile);
310     error(INTERNAL, errmsg);
311     }
312     if (sntp[1] > MAXNP) {
313     sprintf(errmsg, "Too many phi columns in sensor file '%s'",
314     sfile);
315     error(INTERNAL, errmsg);
316     }
317     /* compute boundary angles */
318 greg 2.2 maxtheta = 1.5f*s_theta(sntp[0]-1) - 0.5f*s_theta(sntp[0]-2);
319 greg 2.1 thdiv[0] = .0;
320     for (t = 1; t < sntp[0]; t++)
321 greg 2.2 thdiv[t] = DEGREE/2.*(s_theta(t-1) + s_theta(t));
322 greg 2.1 thdiv[sntp[0]] = maxtheta*DEGREE;
323     phdiv[0] = .0;
324     for (p = 1; p < sntp[1]; p++)
325 greg 2.2 phdiv[p] = DEGREE/2.*(s_phi(p-1) + s_phi(p));
326 greg 2.1 phdiv[sntp[1]] = 2.*PI;
327     /* size our table */
328     tsize = 1. - cos(maxtheta*DEGREE);
329 greg 2.2 psize = PI*tsize/(maxtheta*DEGREE);
330 greg 2.1 if (sntp[0]*sntp[1] < samptot) /* don't overdo resolution */
331     samptot = sntp[0]*sntp[1];
332 greg 2.2 ntheta = (int)(sqrt((double)samptot*tsize/psize) + 0.5);
333 greg 2.1 if (ntheta > MAXNT)
334     ntheta = MAXNT;
335     nphi = samptot/ntheta;
336     pvals = (float *)malloc(sizeof(float)*ntheta*(nphi+1));
337     if (pvals == NULL)
338     error(SYSTEM, "out of memory in init_ptable()");
339     gscale = .0; /* compute our inverse table */
340     for (i = 0; i < sntp[0]; i++) {
341 greg 2.2 rowp = &s_val(i,0);
342 greg 2.1 rowsum[i] = 0.;
343     for (j = 0; j < sntp[1]; j++)
344     rowsum[i] += *rowp++;
345     rowomega[i] = cos(thdiv[i]) - cos(thdiv[i+1]);
346     rowomega[i] *= 2.*PI / (double)sntp[1];
347     gscale += rowsum[i] * rowomega[i];
348     }
349 greg 2.2 for (i = 0; i < ntheta; i++) {
350 greg 2.1 prob = (double)i / (double)ntheta;
351     for (t = 0; t < sntp[0]; t++)
352     if ((prob -= rowsum[t]*rowomega[t]/gscale) <= .0)
353     break;
354     if (t >= sntp[0])
355     error(INTERNAL, "code error 1 in init_ptable()");
356     frac = 1. + prob/(rowsum[t]*rowomega[t]/gscale);
357     tvals[i] = 1. - ( (1.-frac)*cos(thdiv[t]) +
358     frac*cos(thdiv[t+1]) );
359 greg 2.2 /* offset b/c sensor values are centered */
360     if (t <= 0 || frac > 0.5)
361     frac -= 0.5;
362     else if (t >= sntp[0]-1 || frac < 0.5) {
363     frac += 0.5;
364     --t;
365     }
366 greg 2.1 pvals[i*(nphi+1)] = .0f;
367     for (j = 1; j < nphi; j++) {
368     prob = (double)j / (double)nphi;
369 greg 2.2 rowp = &s_val(t,0);
370     rowp1 = &s_val(t+1,0);
371 greg 2.1 for (p = 0; p < sntp[1]; p++) {
372 greg 2.2 if ((prob -= (1.-frac)*rowp[p]/rowsum[t] +
373     frac*rowp1[p]/rowsum[t+1]) <= .0)
374 greg 2.1 break;
375     if (p >= sntp[1])
376     error(INTERNAL,
377     "code error 2 in init_ptable()");
378 greg 2.2 frac1 = 1. + prob/((1.-frac)*rowp[p]/rowsum[t]
379     + frac*rowp1[p]/rowsum[t+1]);
380 greg 2.1 pvals[i*(nphi+1) + j] = (1.-frac1)*phdiv[p] +
381     frac1*phdiv[p+1];
382     }
383     }
384     pvals[i*(nphi+1) + nphi] = (float)(2.*PI);
385     }
386 greg 2.2 tvals[0] = .0f;
387 greg 2.1 tvals[ntheta] = (float)tsize;
388     }
389    
390     /* Get normalized direction from random variables in [0,1) range */
391     static void
392     get_direc(
393     FVECT dvec,
394     double x,
395     double y
396     )
397     {
398     double xfrac = x*ntheta;
399     int tndx = (int)xfrac;
400     double yfrac = y*nphi;
401     int pndx = (int)yfrac;
402     double rad, phi;
403     FVECT dv;
404     int i;
405    
406     xfrac -= (double)tndx;
407     yfrac -= (double)pndx;
408     pndx += tndx*(nphi+1);
409    
410     dv[2] = 1. - ((1.-xfrac)*tvals[tndx] + xfrac*tvals[tndx+1]);
411     rad = sqrt(1. - dv[2]*dv[2]);
412     phi = (1.-yfrac)*pvals[pndx] + yfrac*pvals[pndx+1];
413     dv[0] = -rad*sin(phi);
414     dv[1] = rad*cos(phi);
415     for (i = 3; i--; )
416     dvec[i] = dv[0]*ourview.hvec[i] +
417     dv[1]*ourview.vvec[i] +
418     dv[2]*ourview.vdir[i] ;
419     }
420    
421     /* Get sensor value in the specified direction (normalized) */
422     static float
423     sens_val(
424     FVECT dvec
425     )
426     {
427     FVECT dv;
428     float theta, phi;
429     int t, p;
430    
431     dv[2] = DOT(dvec, ourview.vdir);
432     theta = (float)((1./DEGREE) * acos(dv[2]));
433     if (theta >= maxtheta)
434     return(.0f);
435     dv[0] = DOT(dvec, ourview.hvec);
436     dv[1] = DOT(dvec, ourview.vvec);
437     phi = (float)((1./DEGREE) * atan2(-dv[0], dv[1]));
438     while (phi < .0f) phi += 360.f;
439     t = (int)(theta/maxtheta * sntp[0]);
440     p = (int)(phi*(1./360.) * sntp[1]);
441     /* hack for non-uniform sensor grid */
442 greg 2.2 while (t+1 < sntp[0] && theta >= s_theta(t+1))
443 greg 2.1 ++t;
444 greg 2.2 while (t-1 >= 0 && theta <= s_theta(t-1))
445 greg 2.1 --t;
446 greg 2.2 while (p+1 < sntp[1] && phi >= s_phi(p+1))
447 greg 2.1 ++p;
448 greg 2.2 while (p-1 >= 0 && phi <= s_phi(p-1))
449 greg 2.1 --p;
450 greg 2.2 return(s_val(t,p));
451 greg 2.1 }
452    
453     /* Compute sensor output */
454     static void
455     comp_sensor(
456     char *sfile
457     )
458     {
459     int ndirs = dstrsrc > FTINY ? ndsamps :
460     ndsamps > 0 ? 1 : 0;
461     char *err;
462     int nt, np;
463     COLOR vsum;
464     RAY rr;
465 greg 2.6 double sf;
466 greg 2.1 int i, j;
467     /* set view */
468     ourview.type = VT_ANG;
469     ourview.horiz = ourview.vert = 180.;
470     ourview.hoff = ourview.voff = .0;
471     err = setview(&ourview);
472     if (err != NULL)
473     error(USER, err);
474     /* assign probability table */
475     init_ptable(sfile);
476 greg 2.6 /* stratified MC sampling */
477 greg 2.1 setcolor(vsum, .0f, .0f, .0f);
478     nt = (int)(sqrt((double)nsamps*ntheta/nphi) + .5);
479     np = nsamps/nt;
480 greg 2.6 sf = gscale/nsamps;
481 greg 2.1 for (i = 0; i < nt; i++)
482 greg 2.2 for (j = 0; j < np; j++) {
483 greg 2.5 VCOPY(rr.rorg, ourview.vp);
484 greg 2.2 get_direc(rr.rdir, (i+frandom())/nt, (j+frandom())/np);
485 greg 2.5 if (ourview.vfore > FTINY)
486     VSUM(rr.rorg, rr.rorg, rr.rdir, ourview.vfore);
487     rr.rmax = .0;
488 greg 2.1 rayorigin(&rr, PRIMARY, NULL, NULL);
489 greg 2.6 scalecolor(rr.rcoef, sf);
490 greg 2.1 if (ray_pqueue(&rr) == 1)
491     addcolor(vsum, rr.rcol);
492     }
493 greg 2.6 /* remaining rays pure MC */
494     for (i = nsamps - nt*np; i-- > 0; ) {
495     VCOPY(rr.rorg, ourview.vp);
496     get_direc(rr.rdir, frandom(), frandom());
497     if (ourview.vfore > FTINY)
498     VSUM(rr.rorg, rr.rorg, rr.rdir, ourview.vfore);
499     rr.rmax = .0;
500     rayorigin(&rr, PRIMARY, NULL, NULL);
501     scalecolor(rr.rcoef, sf);
502     if (ray_pqueue(&rr) == 1)
503     addcolor(vsum, rr.rcol);
504     }
505     /* scale partial result */
506     scalecolor(vsum, sf);
507     /* add direct component */
508 greg 2.1 for (i = ndirs; i-- > 0; ) {
509     SRCINDEX si;
510     initsrcindex(&si);
511     while (srcray(&rr, NULL, &si)) {
512 greg 2.6 sf = sens_val(rr.rdir);
513     if (sf <= FTINY)
514 greg 2.1 continue;
515 greg 2.6 sf *= si.dom/ndirs;
516     scalecolor(rr.rcoef, sf);
517 greg 2.1 if (ray_pqueue(&rr) == 1) {
518     multcolor(rr.rcol, rr.rcoef);
519     addcolor(vsum, rr.rcol);
520     }
521     }
522     }
523 greg 2.6 /* finish our calculation */
524 greg 2.1 while (ray_presult(&rr, 0) > 0) {
525     multcolor(rr.rcol, rr.rcoef);
526     addcolor(vsum, rr.rcol);
527     }
528     /* print our result */
529     printf("%.4e %.4e %.4e\n", colval(vsum,RED),
530     colval(vsum,GRN), colval(vsum,BLU));
531     }