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root/radiance/ray/src/cv/bsdfinterp.c
Revision: 2.7
Committed: Mon Nov 26 07:02:20 2012 UTC (11 years, 4 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.6: +5 -6 lines
Log Message:
Fixed bug introduced during last change

File Contents

# User Rev Content
1 greg 2.1 #ifndef lint
2 greg 2.7 static const char RCSid[] = "$Id: bsdfinterp.c,v 2.6 2012/11/22 06:07:17 greg Exp $";
3 greg 2.1 #endif
4     /*
5     * Interpolate BSDF data from radial basis functions in advection mesh.
6     *
7     * G. Ward
8     */
9    
10     #define _USE_MATH_DEFINES
11     #include <stdio.h>
12     #include <stdlib.h>
13     #include <string.h>
14     #include <math.h>
15     #include "bsdfrep.h"
16    
17     /* Insert vertex in ordered list */
18     static void
19     insert_vert(RBFNODE **vlist, RBFNODE *v)
20     {
21     int i, j;
22    
23     for (i = 0; vlist[i] != NULL; i++) {
24     if (v == vlist[i])
25     return;
26     if (v->ord < vlist[i]->ord)
27     break;
28     }
29     for (j = i; vlist[j] != NULL; j++)
30     ;
31     while (j > i) {
32     vlist[j] = vlist[j-1];
33     --j;
34     }
35     vlist[i] = v;
36     }
37    
38     /* Sort triangle edges in standard order */
39     static int
40     order_triangle(MIGRATION *miga[3])
41     {
42     RBFNODE *vert[7];
43     MIGRATION *ord[3];
44     int i;
45     /* order vertices, first */
46     memset(vert, 0, sizeof(vert));
47     for (i = 3; i--; ) {
48     if (miga[i] == NULL)
49     return(0);
50     insert_vert(vert, miga[i]->rbfv[0]);
51     insert_vert(vert, miga[i]->rbfv[1]);
52     }
53     /* should be just 3 vertices */
54 greg 2.4 if ((vert[2] == NULL) | (vert[3] != NULL))
55 greg 2.1 return(0);
56     /* identify edge 0 */
57     for (i = 3; i--; )
58     if (miga[i]->rbfv[0] == vert[0] &&
59     miga[i]->rbfv[1] == vert[1]) {
60     ord[0] = miga[i];
61     break;
62     }
63     if (i < 0)
64     return(0);
65     /* identify edge 1 */
66     for (i = 3; i--; )
67     if (miga[i]->rbfv[0] == vert[1] &&
68     miga[i]->rbfv[1] == vert[2]) {
69     ord[1] = miga[i];
70     break;
71     }
72     if (i < 0)
73     return(0);
74     /* identify edge 2 */
75     for (i = 3; i--; )
76     if (miga[i]->rbfv[0] == vert[0] &&
77     miga[i]->rbfv[1] == vert[2]) {
78     ord[2] = miga[i];
79     break;
80     }
81     if (i < 0)
82     return(0);
83     /* reassign order */
84     miga[0] = ord[0]; miga[1] = ord[1]; miga[2] = ord[2];
85     return(1);
86     }
87    
88 greg 2.4 /* Determine if we are close enough to an edge */
89 greg 2.3 static int
90     on_edge(const MIGRATION *ej, const FVECT ivec)
91     {
92 greg 2.4 double cos_a, cos_b, cos_c, cos_aplusb;
93     /* use triangle inequality */
94     cos_a = DOT(ej->rbfv[0]->invec, ivec);
95     if (cos_a <= 0)
96     return(0);
97    
98     cos_b = DOT(ej->rbfv[1]->invec, ivec);
99     if (cos_b <= 0)
100     return(0);
101 greg 2.3
102 greg 2.4 cos_aplusb = cos_a*cos_b - sqrt((1.-cos_a*cos_a)*(1.-cos_b*cos_b));
103     if (cos_aplusb <= 0)
104     return(0);
105    
106     cos_c = DOT(ej->rbfv[0]->invec, ej->rbfv[1]->invec);
107    
108     return(cos_c - cos_aplusb < .001);
109 greg 2.3 }
110    
111     /* Determine if we are inside the given triangle */
112     static int
113     in_tri(const RBFNODE *v1, const RBFNODE *v2, const RBFNODE *v3, const FVECT p)
114     {
115     FVECT vc;
116     int sgn1, sgn2, sgn3;
117     /* signed volume test */
118     VCROSS(vc, v1->invec, v2->invec);
119     sgn1 = (DOT(p, vc) > 0);
120     VCROSS(vc, v2->invec, v3->invec);
121     sgn2 = (DOT(p, vc) > 0);
122     if (sgn1 != sgn2)
123     return(0);
124     VCROSS(vc, v3->invec, v1->invec);
125     sgn3 = (DOT(p, vc) > 0);
126     return(sgn2 == sgn3);
127     }
128    
129 greg 2.6 /* Test (and set) bitmap for edge */
130 greg 2.4 static int
131     check_edge(unsigned char *emap, int nedges, const MIGRATION *mig, int mark)
132     {
133     int ejndx, bit2check;
134    
135     if (mig->rbfv[0]->ord > mig->rbfv[1]->ord)
136     ejndx = mig->rbfv[1]->ord + (nedges-1)*mig->rbfv[0]->ord;
137     else
138     ejndx = mig->rbfv[0]->ord + (nedges-1)*mig->rbfv[1]->ord;
139    
140     bit2check = 1<<(ejndx&07);
141    
142     if (emap[ejndx>>3] & bit2check)
143     return(0);
144     if (mark)
145     emap[ejndx>>3] |= bit2check;
146     return(1);
147     }
148    
149 greg 2.3 /* Compute intersection with the given position over remaining mesh */
150     static int
151     in_mesh(MIGRATION *miga[3], unsigned char *emap, int nedges,
152     const FVECT ivec, MIGRATION *mig)
153     {
154     MIGRATION *ej1, *ej2;
155     RBFNODE *tv;
156     /* check visitation record */
157 greg 2.4 if (!check_edge(emap, nedges, mig, 1))
158 greg 2.3 return(0);
159     if (on_edge(mig, ivec)) {
160     miga[0] = mig; /* close enough to edge */
161     return(1);
162     }
163     /* do triangles either side */
164     for (ej1 = mig->rbfv[0]->ejl; ej1 != NULL;
165     ej1 = nextedge(mig->rbfv[0],ej1)) {
166 greg 2.4 if (ej1 == mig)
167     continue;
168     tv = opp_rbf(mig->rbfv[0],ej1);
169     for (ej2 = tv->ejl; ej2 != NULL; ej2 = nextedge(tv,ej2))
170     if (opp_rbf(tv,ej2) == mig->rbfv[1]) {
171     int do_ej1 = check_edge(emap, nedges, ej1, 0);
172     int do_ej2 = check_edge(emap, nedges, ej2, 0);
173     if (do_ej1 && in_mesh(miga, emap, nedges, ivec, ej1))
174     return(1);
175     if (do_ej2 && in_mesh(miga, emap, nedges, ivec, ej2))
176     return(1);
177     /* check just once */
178     if (do_ej1 & do_ej2 && in_tri(mig->rbfv[0],
179     mig->rbfv[1], tv, ivec)) {
180     miga[0] = mig;
181     miga[1] = ej1;
182     miga[2] = ej2;
183     return(1);
184 greg 2.3 }
185 greg 2.4 }
186 greg 2.3 }
187 greg 2.4 return(0); /* not near this edge */
188 greg 2.3 }
189    
190 greg 2.1 /* Find edge(s) for interpolating the given vector, applying symmetry */
191     int
192     get_interp(MIGRATION *miga[3], FVECT invec)
193     {
194     miga[0] = miga[1] = miga[2] = NULL;
195     if (single_plane_incident) { /* isotropic BSDF? */
196     RBFNODE *rbf; /* find edge we're on */
197     for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) {
198     if (input_orient*rbf->invec[2] < input_orient*invec[2])
199     break;
200     if (rbf->next != NULL &&
201     input_orient*rbf->next->invec[2] <
202     input_orient*invec[2]) {
203     for (miga[0] = rbf->ejl; miga[0] != NULL;
204     miga[0] = nextedge(rbf,miga[0]))
205 greg 2.5 if (opp_rbf(rbf,miga[0]) == rbf->next) {
206     double nf = 1.-rbf->invec[2]*rbf->invec[2];
207     if (nf > FTINY) {
208     nf = sqrt((1.-invec[2]*invec[2])/nf);
209     invec[0] = nf*rbf->invec[0];
210     invec[1] = nf*rbf->invec[1];
211     }
212 greg 2.1 return(0);
213 greg 2.5 }
214 greg 2.1 break;
215     }
216     }
217     return(-1); /* outside range! */
218     }
219     { /* else use triangle mesh */
220 greg 2.3 int sym = use_symmetry(invec);
221     int nedges = 0;
222     MIGRATION *mep;
223     unsigned char *emap;
224     /* clear visitation map */
225     for (mep = mig_list; mep != NULL; mep = mep->next)
226     ++nedges;
227     emap = (unsigned char *)calloc((nedges*(nedges-1) + 7)>>3, 1);
228     if (emap == NULL) {
229     fprintf(stderr, "%s: Out of memory in get_interp()\n",
230     progname);
231     exit(1);
232     }
233     /* identify intersection */
234     if (!in_mesh(miga, emap, nedges, invec, mig_list))
235     sym = -1; /* outside mesh */
236     else if (miga[1] != NULL &&
237     (miga[2] == NULL || !order_triangle(miga))) {
238 greg 2.1 #ifdef DEBUG
239     fputs("Munged triangle in get_interp()\n", stderr);
240     #endif
241 greg 2.3 sym = -1;
242 greg 2.1 }
243 greg 2.3 free(emap);
244 greg 2.1 return(sym); /* return in standard order */
245     }
246     }
247    
248     /* Advect and allocate new RBF along edge */
249     static RBFNODE *
250     e_advect_rbf(const MIGRATION *mig, const FVECT invec)
251     {
252     RBFNODE *rbf;
253     int n, i, j;
254     double t, full_dist;
255     /* get relative position */
256     t = acos(DOT(invec, mig->rbfv[0]->invec));
257 greg 2.5 if (t < M_PI/grid_res) { /* near first DSF */
258 greg 2.1 n = sizeof(RBFNODE) + sizeof(RBFVAL)*(mig->rbfv[0]->nrbf-1);
259     rbf = (RBFNODE *)malloc(n);
260     if (rbf == NULL)
261     goto memerr;
262     memcpy(rbf, mig->rbfv[0], n); /* just duplicate */
263     return(rbf);
264     }
265     full_dist = acos(DOT(mig->rbfv[0]->invec, mig->rbfv[1]->invec));
266 greg 2.5 if (t > full_dist-M_PI/grid_res) { /* near second DSF */
267 greg 2.1 n = sizeof(RBFNODE) + sizeof(RBFVAL)*(mig->rbfv[1]->nrbf-1);
268     rbf = (RBFNODE *)malloc(n);
269     if (rbf == NULL)
270     goto memerr;
271     memcpy(rbf, mig->rbfv[1], n); /* just duplicate */
272     return(rbf);
273     }
274     t /= full_dist;
275     n = 0; /* count migrating particles */
276     for (i = 0; i < mtx_nrows(mig); i++)
277     for (j = 0; j < mtx_ncols(mig); j++)
278 greg 2.2 n += (mtx_coef(mig,i,j) > FTINY);
279 greg 2.1 #ifdef DEBUG
280     fprintf(stderr, "Input RBFs have %d, %d nodes -> output has %d\n",
281     mig->rbfv[0]->nrbf, mig->rbfv[1]->nrbf, n);
282     #endif
283     rbf = (RBFNODE *)malloc(sizeof(RBFNODE) + sizeof(RBFVAL)*(n-1));
284     if (rbf == NULL)
285     goto memerr;
286     rbf->next = NULL; rbf->ejl = NULL;
287     VCOPY(rbf->invec, invec);
288     rbf->nrbf = n;
289     rbf->vtotal = 1.-t + t*mig->rbfv[1]->vtotal/mig->rbfv[0]->vtotal;
290     n = 0; /* advect RBF lobes */
291     for (i = 0; i < mtx_nrows(mig); i++) {
292     const RBFVAL *rbf0i = &mig->rbfv[0]->rbfa[i];
293     const float peak0 = rbf0i->peak;
294     const double rad0 = R2ANG(rbf0i->crad);
295     FVECT v0;
296     float mv;
297     ovec_from_pos(v0, rbf0i->gx, rbf0i->gy);
298     for (j = 0; j < mtx_ncols(mig); j++)
299 greg 2.2 if ((mv = mtx_coef(mig,i,j)) > FTINY) {
300 greg 2.1 const RBFVAL *rbf1j = &mig->rbfv[1]->rbfa[j];
301     double rad1 = R2ANG(rbf1j->crad);
302     FVECT v;
303     int pos[2];
304     rbf->rbfa[n].peak = peak0 * mv * rbf->vtotal;
305     rbf->rbfa[n].crad = ANG2R(sqrt(rad0*rad0*(1.-t) +
306     rad1*rad1*t));
307     ovec_from_pos(v, rbf1j->gx, rbf1j->gy);
308 greg 2.6 geodesic(v, v0, v, t*full_dist, GEOD_RAD);
309 greg 2.1 pos_from_vec(pos, v);
310     rbf->rbfa[n].gx = pos[0];
311     rbf->rbfa[n].gy = pos[1];
312     ++n;
313     }
314     }
315     rbf->vtotal *= mig->rbfv[0]->vtotal; /* turn ratio into actual */
316     return(rbf);
317     memerr:
318     fprintf(stderr, "%s: Out of memory in e_advect_rbf()\n", progname);
319     exit(1);
320     return(NULL); /* pro forma return */
321     }
322    
323     /* Partially advect between recorded incident angles and allocate new RBF */
324     RBFNODE *
325     advect_rbf(const FVECT invec)
326     {
327     FVECT sivec;
328     MIGRATION *miga[3];
329     RBFNODE *rbf;
330     int sym;
331     float mbfact, mcfact;
332     int n, i, j, k;
333     FVECT v0, v1, v2;
334 greg 2.7 double s, t, t_full;
335 greg 2.1
336     VCOPY(sivec, invec); /* find triangle/edge */
337     sym = get_interp(miga, sivec);
338     if (sym < 0) /* can't interpolate? */
339     return(NULL);
340     if (miga[1] == NULL) { /* advect along edge? */
341     rbf = e_advect_rbf(miga[0], sivec);
342 greg 2.5 if (single_plane_incident)
343     rotate_rbf(rbf, invec);
344     else
345     rev_rbf_symmetry(rbf, sym);
346 greg 2.1 return(rbf);
347     }
348     #ifdef DEBUG
349     if (miga[0]->rbfv[0] != miga[2]->rbfv[0] |
350     miga[0]->rbfv[1] != miga[1]->rbfv[0] |
351     miga[1]->rbfv[1] != miga[2]->rbfv[1]) {
352     fprintf(stderr, "%s: Triangle vertex screw-up!\n", progname);
353     exit(1);
354     }
355     #endif
356     /* figure out position */
357     fcross(v0, miga[2]->rbfv[0]->invec, miga[2]->rbfv[1]->invec);
358     normalize(v0);
359     fcross(v2, miga[1]->rbfv[0]->invec, miga[1]->rbfv[1]->invec);
360     normalize(v2);
361     fcross(v1, sivec, miga[1]->rbfv[1]->invec);
362     normalize(v1);
363 greg 2.7 s = acos(DOT(v0,v1)) / acos(DOT(v0,v2));
364 greg 2.1 geodesic(v1, miga[0]->rbfv[0]->invec, miga[0]->rbfv[1]->invec,
365 greg 2.7 s, GEOD_REL);
366 greg 2.6 t = acos(DOT(v1,sivec)) /
367     (t_full = acos(DOT(v1,miga[1]->rbfv[1]->invec)));
368 greg 2.1 n = 0; /* count migrating particles */
369     for (i = 0; i < mtx_nrows(miga[0]); i++)
370     for (j = 0; j < mtx_ncols(miga[0]); j++)
371 greg 2.2 for (k = (mtx_coef(miga[0],i,j) > FTINY) *
372 greg 2.1 mtx_ncols(miga[2]); k--; )
373 greg 2.4 n += (mtx_coef(miga[2],i,k) > FTINY ||
374 greg 2.2 mtx_coef(miga[1],j,k) > FTINY);
375 greg 2.1 #ifdef DEBUG
376     fprintf(stderr, "Input RBFs have %d, %d, %d nodes -> output has %d\n",
377     miga[0]->rbfv[0]->nrbf, miga[0]->rbfv[1]->nrbf,
378     miga[2]->rbfv[1]->nrbf, n);
379     #endif
380     rbf = (RBFNODE *)malloc(sizeof(RBFNODE) + sizeof(RBFVAL)*(n-1));
381     if (rbf == NULL) {
382     fprintf(stderr, "%s: Out of memory in advect_rbf()\n", progname);
383     exit(1);
384     }
385     rbf->next = NULL; rbf->ejl = NULL;
386     VCOPY(rbf->invec, sivec);
387     rbf->nrbf = n;
388     n = 0; /* compute RBF lobes */
389     mbfact = s * miga[0]->rbfv[1]->vtotal/miga[0]->rbfv[0]->vtotal *
390     (1.-t + t*miga[1]->rbfv[1]->vtotal/miga[1]->rbfv[0]->vtotal);
391     mcfact = (1.-s) *
392     (1.-t + t*miga[2]->rbfv[1]->vtotal/miga[2]->rbfv[0]->vtotal);
393     for (i = 0; i < mtx_nrows(miga[0]); i++) {
394     const RBFVAL *rbf0i = &miga[0]->rbfv[0]->rbfa[i];
395     const float w0i = rbf0i->peak;
396     const double rad0i = R2ANG(rbf0i->crad);
397     ovec_from_pos(v0, rbf0i->gx, rbf0i->gy);
398     for (j = 0; j < mtx_ncols(miga[0]); j++) {
399 greg 2.2 const float ma = mtx_coef(miga[0],i,j);
400 greg 2.1 const RBFVAL *rbf1j;
401     double rad1j, srad2;
402     if (ma <= FTINY)
403     continue;
404     rbf1j = &miga[0]->rbfv[1]->rbfa[j];
405     rad1j = R2ANG(rbf1j->crad);
406     srad2 = (1.-s)*(1.-t)*rad0i*rad0i + s*(1.-t)*rad1j*rad1j;
407     ovec_from_pos(v1, rbf1j->gx, rbf1j->gy);
408 greg 2.7 geodesic(v1, v0, v1, s, GEOD_REL);
409 greg 2.1 for (k = 0; k < mtx_ncols(miga[2]); k++) {
410 greg 2.2 float mb = mtx_coef(miga[1],j,k);
411     float mc = mtx_coef(miga[2],i,k);
412 greg 2.1 const RBFVAL *rbf2k;
413     double rad2k;
414     FVECT vout;
415     int pos[2];
416 greg 2.4 if ((mb <= FTINY) & (mc <= FTINY))
417 greg 2.1 continue;
418     rbf2k = &miga[2]->rbfv[1]->rbfa[k];
419     rbf->rbfa[n].peak = w0i * ma * (mb*mbfact + mc*mcfact);
420     rad2k = R2ANG(rbf2k->crad);
421     rbf->rbfa[n].crad = ANG2R(sqrt(srad2 + t*rad2k*rad2k));
422     ovec_from_pos(v2, rbf2k->gx, rbf2k->gy);
423 greg 2.6 geodesic(vout, v1, v2, t*t_full, GEOD_RAD);
424 greg 2.1 pos_from_vec(pos, vout);
425     rbf->rbfa[n].gx = pos[0];
426     rbf->rbfa[n].gy = pos[1];
427     ++n;
428     }
429     }
430     }
431     rbf->vtotal = miga[0]->rbfv[0]->vtotal * (mbfact + mcfact);
432     rev_rbf_symmetry(rbf, sym);
433     return(rbf);
434     }