1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
|
/*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* The Original Code is Copyright (C) Blender Foundation
* All rights reserved.
*
* The Original Code is: all of this file.
*
* Contributor(s): Janne Karhu, Lukas Toenne
*
* ***** END GPL LICENSE BLOCK *****
*/
/** \file blender/physics/intern/hair_volume.cpp
* \ingroup bph
*/
#include "MEM_guardedalloc.h"
extern "C" {
#include "BLI_math.h"
#include "BLI_utildefines.h"
#include "DNA_texture_types.h"
#include "BKE_effect.h"
}
#include "implicit.h"
#include "eigen_utils.h"
/* ================ Volumetric Hair Interaction ================
* adapted from
*
* Volumetric Methods for Simulation and Rendering of Hair
* (Petrovic, Henne, Anderson, Pixar Technical Memo #06-08, Pixar Animation Studios)
*
* as well as
*
* "Detail Preserving Continuum Simulation of Straight Hair"
* (McAdams, Selle 2009)
*/
/* Note about array indexing:
* Generally the arrays here are one-dimensional.
* The relation between 3D indices and the array offset is
* offset = x + res_x * y + res_x * res_y * z
*/
static float I[3][3] = {{1, 0, 0}, {0, 1, 0}, {0, 0, 1}};
BLI_INLINE int floor_int(float value)
{
return value > 0.0f ? (int)value : ((int)value) - 1;
}
BLI_INLINE float floor_mod(float value)
{
return value - floorf(value);
}
BLI_INLINE int hair_grid_size(const int res[3])
{
return res[0] * res[1] * res[2];
}
typedef struct HairGridVert {
int samples;
float velocity[3];
float density;
float velocity_smooth[3];
} HairGridVert;
typedef struct HairGrid {
HairGridVert *verts;
int res[3];
float gmin[3], gmax[3];
float cellsize, inv_cellsize;
float debug1, debug2;
int debug3, debug4;
} HairGrid;
#define HAIR_GRID_INDEX_AXIS(vec, res, gmin, scale, axis) ( min_ii( max_ii( (int)((vec[axis] - gmin[axis]) * scale), 0), res[axis]-2 ) )
BLI_INLINE int hair_grid_offset(const float vec[3], const int res[3], const float gmin[3], float scale)
{
int i, j, k;
i = HAIR_GRID_INDEX_AXIS(vec, res, gmin, scale, 0);
j = HAIR_GRID_INDEX_AXIS(vec, res, gmin, scale, 1);
k = HAIR_GRID_INDEX_AXIS(vec, res, gmin, scale, 2);
return i + (j + k*res[1])*res[0];
}
BLI_INLINE int hair_grid_interp_weights(const int res[3], const float gmin[3], float scale, const float vec[3], float uvw[3])
{
int i, j, k, offset;
i = HAIR_GRID_INDEX_AXIS(vec, res, gmin, scale, 0);
j = HAIR_GRID_INDEX_AXIS(vec, res, gmin, scale, 1);
k = HAIR_GRID_INDEX_AXIS(vec, res, gmin, scale, 2);
offset = i + (j + k*res[1])*res[0];
uvw[0] = (vec[0] - gmin[0]) * scale - (float)i;
uvw[1] = (vec[1] - gmin[1]) * scale - (float)j;
uvw[2] = (vec[2] - gmin[2]) * scale - (float)k;
// BLI_assert(0.0f <= uvw[0] && uvw[0] <= 1.0001f);
// BLI_assert(0.0f <= uvw[1] && uvw[1] <= 1.0001f);
// BLI_assert(0.0f <= uvw[2] && uvw[2] <= 1.0001f);
return offset;
}
BLI_INLINE void hair_grid_interpolate(const HairGridVert *grid, const int res[3], const float gmin[3], float scale, const float vec[3],
float *density, float velocity[3], float vel_smooth[3], float density_gradient[3], float velocity_gradient[3][3])
{
HairGridVert data[8];
float uvw[3], muvw[3];
int res2 = res[1] * res[0];
int offset;
offset = hair_grid_interp_weights(res, gmin, scale, vec, uvw);
muvw[0] = 1.0f - uvw[0];
muvw[1] = 1.0f - uvw[1];
muvw[2] = 1.0f - uvw[2];
data[0] = grid[offset ];
data[1] = grid[offset +1];
data[2] = grid[offset +res[0] ];
data[3] = grid[offset +res[0]+1];
data[4] = grid[offset+res2 ];
data[5] = grid[offset+res2 +1];
data[6] = grid[offset+res2+res[0] ];
data[7] = grid[offset+res2+res[0]+1];
if (density) {
*density = muvw[2]*( muvw[1]*( muvw[0]*data[0].density + uvw[0]*data[1].density ) +
uvw[1]*( muvw[0]*data[2].density + uvw[0]*data[3].density ) ) +
uvw[2]*( muvw[1]*( muvw[0]*data[4].density + uvw[0]*data[5].density ) +
uvw[1]*( muvw[0]*data[6].density + uvw[0]*data[7].density ) );
}
if (velocity) {
int k;
for (k = 0; k < 3; ++k) {
velocity[k] = muvw[2]*( muvw[1]*( muvw[0]*data[0].velocity[k] + uvw[0]*data[1].velocity[k] ) +
uvw[1]*( muvw[0]*data[2].velocity[k] + uvw[0]*data[3].velocity[k] ) ) +
uvw[2]*( muvw[1]*( muvw[0]*data[4].velocity[k] + uvw[0]*data[5].velocity[k] ) +
uvw[1]*( muvw[0]*data[6].velocity[k] + uvw[0]*data[7].velocity[k] ) );
}
}
if (vel_smooth) {
int k;
for (k = 0; k < 3; ++k) {
vel_smooth[k] = muvw[2]*( muvw[1]*( muvw[0]*data[0].velocity_smooth[k] + uvw[0]*data[1].velocity_smooth[k] ) +
uvw[1]*( muvw[0]*data[2].velocity_smooth[k] + uvw[0]*data[3].velocity_smooth[k] ) ) +
uvw[2]*( muvw[1]*( muvw[0]*data[4].velocity_smooth[k] + uvw[0]*data[5].velocity_smooth[k] ) +
uvw[1]*( muvw[0]*data[6].velocity_smooth[k] + uvw[0]*data[7].velocity_smooth[k] ) );
}
}
if (density_gradient) {
density_gradient[0] = muvw[1] * muvw[2] * ( data[0].density - data[1].density ) +
uvw[1] * muvw[2] * ( data[2].density - data[3].density ) +
muvw[1] * uvw[2] * ( data[4].density - data[5].density ) +
uvw[1] * uvw[2] * ( data[6].density - data[7].density );
density_gradient[1] = muvw[2] * muvw[0] * ( data[0].density - data[2].density ) +
uvw[2] * muvw[0] * ( data[4].density - data[6].density ) +
muvw[2] * uvw[0] * ( data[1].density - data[3].density ) +
uvw[2] * uvw[0] * ( data[5].density - data[7].density );
density_gradient[2] = muvw[2] * muvw[0] * ( data[0].density - data[4].density ) +
uvw[2] * muvw[0] * ( data[1].density - data[5].density ) +
muvw[2] * uvw[0] * ( data[2].density - data[6].density ) +
uvw[2] * uvw[0] * ( data[3].density - data[7].density );
}
if (velocity_gradient) {
/* XXX TODO */
zero_m3(velocity_gradient);
}
}
void BPH_hair_volume_vertex_grid_forces(HairGrid *grid, const float x[3], const float v[3],
float smoothfac, float pressurefac, float minpressure,
float f[3], float dfdx[3][3], float dfdv[3][3])
{
float gdensity, gvelocity[3], ggrad[3], gvelgrad[3][3], gradlen;
hair_grid_interpolate(grid->verts, grid->res, grid->gmin, grid->inv_cellsize, x, &gdensity, gvelocity, NULL, ggrad, gvelgrad);
zero_v3(f);
sub_v3_v3(gvelocity, v);
mul_v3_v3fl(f, gvelocity, smoothfac);
gradlen = normalize_v3(ggrad) - minpressure;
if (gradlen > 0.0f) {
mul_v3_fl(ggrad, gradlen);
madd_v3_v3fl(f, ggrad, pressurefac);
}
zero_m3(dfdx);
sub_m3_m3m3(dfdv, gvelgrad, I);
mul_m3_fl(dfdv, smoothfac);
}
void BPH_hair_volume_grid_interpolate(HairGrid *grid, const float x[3],
float *density, float velocity[3], float velocity_smooth[3], float density_gradient[3], float velocity_gradient[3][3])
{
hair_grid_interpolate(grid->verts, grid->res, grid->gmin, grid->inv_cellsize, x, density, velocity, velocity_smooth, density_gradient, velocity_gradient);
}
void BPH_hair_volume_grid_velocity(HairGrid *grid, const float x[3], const float v[3],
float fluid_factor,
float r_v[3])
{
float gdensity, gvelocity[3], gvel_smooth[3], ggrad[3], gvelgrad[3][3];
float v_pic[3], v_flip[3];
hair_grid_interpolate(grid->verts, grid->res, grid->gmin, grid->inv_cellsize, x, &gdensity, gvelocity, gvel_smooth, ggrad, gvelgrad);
/* velocity according to PIC method (Particle-in-Cell) */
copy_v3_v3(v_pic, gvel_smooth);
/* velocity according to FLIP method (Fluid-Implicit-Particle) */
sub_v3_v3v3(v_flip, gvel_smooth, gvelocity);
add_v3_v3(v_flip, v);
interp_v3_v3v3(r_v, v_pic, v_flip, fluid_factor);
}
void BPH_hair_volume_grid_clear(HairGrid *grid)
{
const int size = hair_grid_size(grid->res);
int i;
for (i = 0; i < size; ++i) {
zero_v3(grid->verts[i].velocity);
zero_v3(grid->verts[i].velocity_smooth);
grid->verts[i].density = 0.0f;
grid->verts[i].samples = 0;
}
}
BLI_INLINE bool hair_grid_point_valid(const float vec[3], float gmin[3], float gmax[3])
{
return !(vec[0] < gmin[0] || vec[1] < gmin[1] || vec[2] < gmin[2] ||
vec[0] > gmax[0] || vec[1] > gmax[1] || vec[2] > gmax[2]);
}
BLI_INLINE float dist_tent_v3f3(const float a[3], float x, float y, float z)
{
float w = (1.0f - fabsf(a[0] - x)) * (1.0f - fabsf(a[1] - y)) * (1.0f - fabsf(a[2] - z));
return w;
}
BLI_INLINE float weights_sum(const float weights[8])
{
float totweight = 0.0f;
int i;
for (i = 0; i < 8; ++i)
totweight += weights[i];
return totweight;
}
/* returns the grid array offset as well to avoid redundant calculation */
BLI_INLINE int hair_grid_weights(const int res[3], const float gmin[3], float scale, const float vec[3], float weights[8])
{
int i, j, k, offset;
float uvw[3];
i = HAIR_GRID_INDEX_AXIS(vec, res, gmin, scale, 0);
j = HAIR_GRID_INDEX_AXIS(vec, res, gmin, scale, 1);
k = HAIR_GRID_INDEX_AXIS(vec, res, gmin, scale, 2);
offset = i + (j + k*res[1])*res[0];
uvw[0] = (vec[0] - gmin[0]) * scale;
uvw[1] = (vec[1] - gmin[1]) * scale;
uvw[2] = (vec[2] - gmin[2]) * scale;
weights[0] = dist_tent_v3f3(uvw, (float)i , (float)j , (float)k );
weights[1] = dist_tent_v3f3(uvw, (float)(i+1), (float)j , (float)k );
weights[2] = dist_tent_v3f3(uvw, (float)i , (float)(j+1), (float)k );
weights[3] = dist_tent_v3f3(uvw, (float)(i+1), (float)(j+1), (float)k );
weights[4] = dist_tent_v3f3(uvw, (float)i , (float)j , (float)(k+1));
weights[5] = dist_tent_v3f3(uvw, (float)(i+1), (float)j , (float)(k+1));
weights[6] = dist_tent_v3f3(uvw, (float)i , (float)(j+1), (float)(k+1));
weights[7] = dist_tent_v3f3(uvw, (float)(i+1), (float)(j+1), (float)(k+1));
// BLI_assert(fabsf(weights_sum(weights) - 1.0f) < 0.0001f);
return offset;
}
BLI_INLINE void grid_to_world(HairGrid *grid, float vecw[3], const float vec[3])
{
copy_v3_v3(vecw, vec);
mul_v3_fl(vecw, grid->cellsize);
add_v3_v3(vecw, grid->gmin);
}
void BPH_hair_volume_add_vertex(HairGrid *grid, const float x[3], const float v[3])
{
const int res[3] = { grid->res[0], grid->res[1], grid->res[2] };
float weights[8];
int di, dj, dk;
int offset;
if (!hair_grid_point_valid(x, grid->gmin, grid->gmax))
return;
offset = hair_grid_weights(res, grid->gmin, grid->inv_cellsize, x, weights);
for (di = 0; di < 2; ++di) {
for (dj = 0; dj < 2; ++dj) {
for (dk = 0; dk < 2; ++dk) {
int voffset = offset + di + (dj + dk*res[1])*res[0];
int iw = di + dj*2 + dk*4;
grid->verts[voffset].density += weights[iw];
madd_v3_v3fl(grid->verts[voffset].velocity, v, weights[iw]);
}
}
}
}
#if 0
BLI_INLINE void hair_volume_eval_grid_vertex(HairGridVert *vert, const float loc[3], float radius, float dist_scale,
const float x2[3], const float v2[3], const float x3[3], const float v3[3])
{
float closest[3], lambda, dist, weight;
lambda = closest_to_line_v3(closest, loc, x2, x3);
dist = len_v3v3(closest, loc);
weight = (radius - dist) * dist_scale;
if (weight > 0.0f) {
float vel[3];
interp_v3_v3v3(vel, v2, v3, lambda);
madd_v3_v3fl(vert->velocity, vel, weight);
vert->density += weight;
vert->samples += 1;
}
}
BLI_INLINE int major_axis_v3(const float v[3])
{
const float a = fabsf(v[0]);
const float b = fabsf(v[1]);
const float c = fabsf(v[2]);
return a > b ? (a > c ? 0 : 2) : (b > c ? 1 : 2);
}
BLI_INLINE void hair_volume_add_segment_2D(HairGrid *grid,
const float UNUSED(x1[3]), const float UNUSED(v1[3]), const float x2[3], const float v2[3],
const float x3[3], const float v3[3], const float UNUSED(x4[3]), const float UNUSED(v4[3]),
const float UNUSED(dir1[3]), const float dir2[3], const float UNUSED(dir3[3]),
int resj, int resk, int jmin, int jmax, int kmin, int kmax,
HairGridVert *vert, int stride_j, int stride_k, const float loc[3], int axis_j, int axis_k,
int debug_i)
{
const float radius = 1.5f;
const float dist_scale = grid->inv_cellsize;
int j, k;
/* boundary checks to be safe */
CLAMP_MIN(jmin, 0);
CLAMP_MAX(jmax, resj-1);
CLAMP_MIN(kmin, 0);
CLAMP_MAX(kmax, resk-1);
HairGridVert *vert_j = vert + jmin * stride_j;
float loc_j[3] = { loc[0], loc[1], loc[2] };
loc_j[axis_j] += (float)jmin;
for (j = jmin; j <= jmax; ++j, vert_j += stride_j, loc_j[axis_j] += 1.0f) {
HairGridVert *vert_k = vert_j + kmin * stride_k;
float loc_k[3] = { loc_j[0], loc_j[1], loc_j[2] };
loc_k[axis_k] += (float)kmin;
for (k = kmin; k <= kmax; ++k, vert_k += stride_k, loc_k[axis_k] += 1.0f) {
hair_volume_eval_grid_vertex(vert_k, loc_k, radius, dist_scale, x2, v2, x3, v3);
#if 0
{
float wloc[3], x2w[3], x3w[3];
grid_to_world(grid, wloc, loc_k);
grid_to_world(grid, x2w, x2);
grid_to_world(grid, x3w, x3);
if (vert_k->samples > 0)
BKE_sim_debug_data_add_circle(wloc, 0.01f, 1.0, 1.0, 0.3, "grid", 2525, debug_i, j, k);
if (grid->debug_value) {
BKE_sim_debug_data_add_dot(wloc, 1, 0, 0, "grid", 93, debug_i, j, k);
BKE_sim_debug_data_add_dot(x2w, 0.1, 0.1, 0.7, "grid", 649, debug_i, j, k);
BKE_sim_debug_data_add_line(wloc, x2w, 0.3, 0.8, 0.3, "grid", 253, debug_i, j, k);
BKE_sim_debug_data_add_line(wloc, x3w, 0.8, 0.3, 0.3, "grid", 254, debug_i, j, k);
// BKE_sim_debug_data_add_circle(x2w, len_v3v3(wloc, x2w), 0.2, 0.7, 0.2, "grid", 255, i, j, k);
}
}
#endif
}
}
}
/* Uses a variation of Bresenham's algorithm for rasterizing a 3D grid with a line segment.
*
* The radius of influence around a segment is assumed to be at most 2*cellsize,
* i.e. only cells containing the segment and their direct neighbors are examined.
*
*
*/
void BPH_hair_volume_add_segment(HairGrid *grid,
const float x1[3], const float v1[3], const float x2[3], const float v2[3],
const float x3[3], const float v3[3], const float x4[3], const float v4[3],
const float dir1[3], const float dir2[3], const float dir3[3])
{
const int res[3] = { grid->res[0], grid->res[1], grid->res[2] };
/* find the primary direction from the major axis of the direction vector */
const int axis0 = major_axis_v3(dir2);
const int axis1 = (axis0 + 1) % 3;
const int axis2 = (axis0 + 2) % 3;
/* vertex buffer offset factors along cardinal axes */
const int strides[3] = { 1, res[0], res[0] * res[1] };
const int stride0 = strides[axis0];
const int stride1 = strides[axis1];
const int stride2 = strides[axis2];
/* increment of secondary directions per step in the primary direction
* note: we always go in the positive direction along axis0, so the sign can be inverted
*/
const float inc1 = dir2[axis1] / dir2[axis0];
const float inc2 = dir2[axis2] / dir2[axis0];
/* start/end points, so increment along axis0 is always positive */
const float *start = x2[axis0] < x3[axis0] ? x2 : x3;
const float *end = x2[axis0] < x3[axis0] ? x3 : x2;
const float start0 = start[axis0], start1 = start[axis1], start2 = start[axis2];
const float end0 = end[axis0];
/* range along primary direction */
const int imin = max_ii(floor_int(start[axis0]) - 1, 0);
const int imax = min_ii(floor_int(end[axis0]) + 2, res[axis0]-1);
float h = 0.0f;
HairGridVert *vert0;
float loc0[3];
int j0, k0, j0_prev, k0_prev;
int i;
for (i = imin; i <= imax; ++i) {
float shift1, shift2; /* fraction of a full cell shift [0.0, 1.0) */
int jmin, jmax, kmin, kmax;
h = CLAMPIS((float)i, start0, end0);
shift1 = start1 + (h - start0) * inc1;
shift2 = start2 + (h - start0) * inc2;
j0_prev = j0;
j0 = floor_int(shift1);
k0_prev = k0;
k0 = floor_int(shift2);
if (i > imin) {
jmin = min_ii(j0, j0_prev);
jmax = max_ii(j0, j0_prev);
kmin = min_ii(k0, k0_prev);
kmax = max_ii(k0, k0_prev);
}
else {
jmin = jmax = j0;
kmin = kmax = k0;
}
vert0 = grid->verts + i * stride0;
loc0[axis0] = (float)i;
loc0[axis1] = 0.0f;
loc0[axis2] = 0.0f;
hair_volume_add_segment_2D(grid, x1, v1, x2, v2, x3, v3, x4, v4, dir1, dir2, dir3,
res[axis1], res[axis2], jmin-1, jmax+2, kmin-1, kmax+2,
vert0, stride1, stride2, loc0, axis1, axis2,
i);
}
}
#else
BLI_INLINE void hair_volume_eval_grid_vertex_sample(HairGridVert *vert, const float loc[3], float radius, float dist_scale,
const float x[3], const float v[3])
{
float dist, weight;
dist = len_v3v3(x, loc);
weight = (radius - dist) * dist_scale;
if (weight > 0.0f) {
madd_v3_v3fl(vert->velocity, v, weight);
vert->density += weight;
vert->samples += 1;
}
}
/* XXX simplified test implementation using a series of discrete sample along the segment,
* instead of finding the closest point for all affected grid vertices.
*/
void BPH_hair_volume_add_segment(HairGrid *grid,
const float UNUSED(x1[3]), const float UNUSED(v1[3]), const float x2[3], const float v2[3],
const float x3[3], const float v3[3], const float UNUSED(x4[3]), const float UNUSED(v4[3]),
const float UNUSED(dir1[3]), const float UNUSED(dir2[3]), const float UNUSED(dir3[3]))
{
const float radius = 1.5f;
const float dist_scale = grid->inv_cellsize;
const int res[3] = { grid->res[0], grid->res[1], grid->res[2] };
const int stride[3] = { 1, res[0], res[0] * res[1] };
const int num_samples = 10;
int s;
for (s = 0; s < num_samples; ++s) {
float x[3], v[3];
int i, j, k;
float f = (float)s / (float)(num_samples-1);
interp_v3_v3v3(x, x2, x3, f);
interp_v3_v3v3(v, v2, v3, f);
int imin = max_ii(floor_int(x[0]) - 2, 0);
int imax = min_ii(floor_int(x[0]) + 2, res[0]-1);
int jmin = max_ii(floor_int(x[1]) - 2, 0);
int jmax = min_ii(floor_int(x[1]) + 2, res[1]-1);
int kmin = max_ii(floor_int(x[2]) - 2, 0);
int kmax = min_ii(floor_int(x[2]) + 2, res[2]-1);
for (k = kmin; k <= kmax; ++k) {
for (j = jmin; j <= jmax; ++j) {
for (i = imin; i <= imax; ++i) {
float loc[3] = { (float)i, (float)j, (float)k };
HairGridVert *vert = grid->verts + i * stride[0] + j * stride[1] + k * stride[2];
hair_volume_eval_grid_vertex_sample(vert, loc, radius, dist_scale, x, v);
}
}
}
}
}
#endif
void BPH_hair_volume_normalize_vertex_grid(HairGrid *grid)
{
int i, size = hair_grid_size(grid->res);
/* divide velocity with density */
for (i = 0; i < size; i++) {
float density = grid->verts[i].density;
if (density > 0.0f)
mul_v3_fl(grid->verts[i].velocity, 1.0f/density);
}
}
static const float density_threshold = 0.001f; /* cells with density below this are considered empty */
/* Contribution of target density pressure to the laplacian in the pressure poisson equation.
* This is based on the model found in
* "Two-way Coupled SPH and Particle Level Set Fluid Simulation" (Losasso et al., 2008)
*/
BLI_INLINE float hair_volume_density_divergence(float density, float target_density, float strength)
{
if (density > density_threshold && density > target_density)
return strength * logf(target_density / density);
else
return 0.0f;
}
bool BPH_hair_volume_solve_divergence(HairGrid *grid, float dt, float target_density, float target_strength)
{
const float flowfac = grid->cellsize;
const float inv_flowfac = 1.0f / grid->cellsize;
/*const int num_cells = hair_grid_size(grid->res);*/
const int res[3] = { grid->res[0], grid->res[1], grid->res[2] };
const int resA[3] = { grid->res[0] + 2, grid->res[1] + 2, grid->res[2] + 2 };
const int stride0 = 1;
const int stride1 = grid->res[0];
const int stride2 = grid->res[1] * grid->res[0];
const int strideA0 = 1;
const int strideA1 = grid->res[0] + 2;
const int strideA2 = (grid->res[1] + 2) * (grid->res[0] + 2);
const int num_cells = res[0] * res[1] * res[2];
const int num_cellsA = (res[0] + 2) * (res[1] + 2) * (res[2] + 2);
HairGridVert *vert_start = grid->verts - (stride0 + stride1 + stride2);
HairGridVert *vert;
int i, j, k;
#define MARGIN_i0 (i < 1)
#define MARGIN_j0 (j < 1)
#define MARGIN_k0 (k < 1)
#define MARGIN_i1 (i >= resA[0]-1)
#define MARGIN_j1 (j >= resA[1]-1)
#define MARGIN_k1 (k >= resA[2]-1)
#define NEIGHBOR_MARGIN_i0 (i < 2)
#define NEIGHBOR_MARGIN_j0 (j < 2)
#define NEIGHBOR_MARGIN_k0 (k < 2)
#define NEIGHBOR_MARGIN_i1 (i >= resA[0]-2)
#define NEIGHBOR_MARGIN_j1 (j >= resA[1]-2)
#define NEIGHBOR_MARGIN_k1 (k >= resA[2]-2)
BLI_assert(num_cells >= 1);
/* Calculate divergence */
lVector B(num_cellsA);
for (k = 0; k < resA[2]; ++k) {
for (j = 0; j < resA[1]; ++j) {
for (i = 0; i < resA[0]; ++i) {
int u = i * strideA0 + j * strideA1 + k * strideA2;
bool is_margin = MARGIN_i0 || MARGIN_i1 || MARGIN_j0 || MARGIN_j1 || MARGIN_k0 || MARGIN_k1;
if (is_margin) {
B[u] = 0.0f;
continue;
}
vert = vert_start + i * stride0 + j * stride1 + k * stride2;
const float *v0 = vert->velocity;
float dx = 0.0f, dy = 0.0f, dz = 0.0f;
if (!NEIGHBOR_MARGIN_i0)
dx += v0[0] - (vert - stride0)->velocity[0];
if (!NEIGHBOR_MARGIN_i1)
dx += (vert + stride0)->velocity[0] - v0[0];
if (!NEIGHBOR_MARGIN_j0)
dy += v0[1] - (vert - stride1)->velocity[1];
if (!NEIGHBOR_MARGIN_j1)
dy += (vert + stride1)->velocity[1] - v0[1];
if (!NEIGHBOR_MARGIN_k0)
dz += v0[2] - (vert - stride2)->velocity[2];
if (!NEIGHBOR_MARGIN_k1)
dz += (vert + stride2)->velocity[2] - v0[2];
float divergence = -0.5f * flowfac * (dx + dy + dz);
/* adjustment term for target density */
float target = hair_volume_density_divergence(vert->density, target_density, target_strength);
/* B vector contains the finite difference approximation of the velocity divergence.
* Note: according to the discretized Navier-Stokes equation the rhs vector
* and resulting pressure gradient should be multiplied by the (inverse) density;
* however, this is already included in the weighting of hair velocities on the grid!
*/
B[u] = divergence - target;
#if 0
{
float wloc[3], loc[3];
float col0[3] = {0.0, 0.0, 0.0};
float colp[3] = {0.0, 1.0, 1.0};
float coln[3] = {1.0, 0.0, 1.0};
float col[3];
float fac;
loc[0] = (float)(i - 1);
loc[1] = (float)(j - 1);
loc[2] = (float)(k - 1);
grid_to_world(grid, wloc, loc);
if (divergence > 0.0f) {
fac = CLAMPIS(divergence * target_strength, 0.0, 1.0);
interp_v3_v3v3(col, col0, colp, fac);
}
else {
fac = CLAMPIS(-divergence * target_strength, 0.0, 1.0);
interp_v3_v3v3(col, col0, coln, fac);
}
if (fac > 0.05f)
BKE_sim_debug_data_add_circle(grid->debug_data, wloc, 0.01f, col[0], col[1], col[2], "grid", 5522, i, j, k);
}
#endif
}
}
}
/* Main Poisson equation system:
* This is derived from the discretezation of the Poisson equation
* div(grad(p)) = div(v)
*
* The finite difference approximation yields the linear equation system described here:
* http://en.wikipedia.org/wiki/Discrete_Poisson_equation
*/
lMatrix A(num_cellsA, num_cellsA);
/* Reserve space for the base equation system (without boundary conditions).
* Each column contains a factor 6 on the diagonal
* and up to 6 factors -1 on other places.
*/
A.reserve(Eigen::VectorXi::Constant(num_cellsA, 7));
for (k = 0; k < resA[2]; ++k) {
for (j = 0; j < resA[1]; ++j) {
for (i = 0; i < resA[0]; ++i) {
int u = i * strideA0 + j * strideA1 + k * strideA2;
bool is_margin = MARGIN_i0 || MARGIN_i1 || MARGIN_j0 || MARGIN_j1 || MARGIN_k0 || MARGIN_k1;
vert = vert_start + i * stride0 + j * stride1 + k * stride2;
if (!is_margin && vert->density > density_threshold) {
int neighbors_lo = 0;
int neighbors_hi = 0;
int non_solid_neighbors = 0;
int neighbor_lo_index[3];
int neighbor_hi_index[3];
int n;
/* check for upper bounds in advance
* to get the correct number of neighbors,
* needed for the diagonal element
*/
if (!NEIGHBOR_MARGIN_k0 && (vert - stride2)->density > density_threshold)
neighbor_lo_index[neighbors_lo++] = u - strideA2;
if (!NEIGHBOR_MARGIN_j0 && (vert - stride1)->density > density_threshold)
neighbor_lo_index[neighbors_lo++] = u - strideA1;
if (!NEIGHBOR_MARGIN_i0 && (vert - stride0)->density > density_threshold)
neighbor_lo_index[neighbors_lo++] = u - strideA0;
if (!NEIGHBOR_MARGIN_i1 && (vert + stride0)->density > density_threshold)
neighbor_hi_index[neighbors_hi++] = u + strideA0;
if (!NEIGHBOR_MARGIN_j1 && (vert + stride1)->density > density_threshold)
neighbor_hi_index[neighbors_hi++] = u + strideA1;
if (!NEIGHBOR_MARGIN_k1 && (vert + stride2)->density > density_threshold)
neighbor_hi_index[neighbors_hi++] = u + strideA2;
/*int liquid_neighbors = neighbors_lo + neighbors_hi;*/
non_solid_neighbors = 6;
for (n = 0; n < neighbors_lo; ++n)
A.insert(neighbor_lo_index[n], u) = -1.0f;
A.insert(u, u) = (float)non_solid_neighbors;
for (n = 0; n < neighbors_hi; ++n)
A.insert(neighbor_hi_index[n], u) = -1.0f;
}
else {
A.insert(u, u) = 1.0f;
}
}
}
}
ConjugateGradient cg;
cg.setMaxIterations(100);
cg.setTolerance(0.01f);
cg.compute(A);
lVector p = cg.solve(B);
if (cg.info() == Eigen::Success) {
/* Calculate velocity = grad(p) */
for (k = 0; k < resA[2]; ++k) {
for (j = 0; j < resA[1]; ++j) {
for (i = 0; i < resA[0]; ++i) {
int u = i * strideA0 + j * strideA1 + k * strideA2;
bool is_margin = MARGIN_i0 || MARGIN_i1 || MARGIN_j0 || MARGIN_j1 || MARGIN_k0 || MARGIN_k1;
if (is_margin)
continue;
vert = vert_start + i * stride0 + j * stride1 + k * stride2;
if (vert->density > density_threshold) {
float p_left = p[u - strideA0];
float p_right = p[u + strideA0];
float p_down = p[u - strideA1];
float p_up = p[u + strideA1];
float p_bottom = p[u - strideA2];
float p_top = p[u + strideA2];
/* finite difference estimate of pressure gradient */
float dvel[3];
dvel[0] = p_right - p_left;
dvel[1] = p_up - p_down;
dvel[2] = p_top - p_bottom;
mul_v3_fl(dvel, -0.5f * inv_flowfac);
/* pressure gradient describes velocity delta */
add_v3_v3v3(vert->velocity_smooth, vert->velocity, dvel);
}
else {
zero_v3(vert->velocity_smooth);
}
}
}
}
#if 0
{
int axis = 0;
float offset = 0.0f;
int slice = (offset - grid->gmin[axis]) / grid->cellsize;
for (k = 0; k < resA[2]; ++k) {
for (j = 0; j < resA[1]; ++j) {
for (i = 0; i < resA[0]; ++i) {
int u = i * strideA0 + j * strideA1 + k * strideA2;
bool is_margin = MARGIN_i0 || MARGIN_i1 || MARGIN_j0 || MARGIN_j1 || MARGIN_k0 || MARGIN_k1;
if (i != slice)
continue;
vert = vert_start + i * stride0 + j * stride1 + k * stride2;
float wloc[3], loc[3];
float col0[3] = {0.0, 0.0, 0.0};
float colp[3] = {0.0, 1.0, 1.0};
float coln[3] = {1.0, 0.0, 1.0};
float col[3];
float fac;
loc[0] = (float)(i - 1);
loc[1] = (float)(j - 1);
loc[2] = (float)(k - 1);
grid_to_world(grid, wloc, loc);
float pressure = p[u];
if (pressure > 0.0f) {
fac = CLAMPIS(pressure * grid->debug1, 0.0, 1.0);
interp_v3_v3v3(col, col0, colp, fac);
}
else {
fac = CLAMPIS(-pressure * grid->debug1, 0.0, 1.0);
interp_v3_v3v3(col, col0, coln, fac);
}
if (fac > 0.05f)
BKE_sim_debug_data_add_circle(grid->debug_data, wloc, 0.01f, col[0], col[1], col[2], "grid", 5533, i, j, k);
if (!is_margin) {
float dvel[3];
sub_v3_v3v3(dvel, vert->velocity_smooth, vert->velocity);
// BKE_sim_debug_data_add_vector(grid->debug_data, wloc, dvel, 1, 1, 1, "grid", 5566, i, j, k);
}
if (!is_margin) {
float d = CLAMPIS(vert->density * grid->debug2, 0.0f, 1.0f);
float col0[3] = {0.3, 0.3, 0.3};
float colp[3] = {0.0, 0.0, 1.0};
float col[3];
interp_v3_v3v3(col, col0, colp, d);
// if (d > 0.05f)
// BKE_sim_debug_data_add_dot(grid->debug_data, wloc, col[0], col[1], col[2], "grid", 5544, i, j, k);
}
}
}
}
}
#endif
return true;
}
else {
/* Clear result in case of error */
for (i = 0, vert = grid->verts; i < num_cells; ++i, ++vert) {
zero_v3(vert->velocity_smooth);
}
return false;
}
}
#if 0 /* XXX weighting is incorrect, disabled for now */
/* Velocity filter kernel
* See http://en.wikipedia.org/wiki/Filter_%28large_eddy_simulation%29
*/
BLI_INLINE void hair_volume_filter_box_convolute(HairVertexGrid *grid, float invD, const int kernel_size[3], int i, int j, int k)
{
int res = grid->res;
int p, q, r;
int minp = max_ii(i - kernel_size[0], 0), maxp = min_ii(i + kernel_size[0], res-1);
int minq = max_ii(j - kernel_size[1], 0), maxq = min_ii(j + kernel_size[1], res-1);
int minr = max_ii(k - kernel_size[2], 0), maxr = min_ii(k + kernel_size[2], res-1);
int offset, kernel_offset, kernel_dq, kernel_dr;
HairGridVert *verts;
float *vel_smooth;
offset = i + (j + k*res)*res;
verts = grid->verts;
vel_smooth = verts[offset].velocity_smooth;
kernel_offset = minp + (minq + minr*res)*res;
kernel_dq = res;
kernel_dr = res * res;
for (r = minr; r <= maxr; ++r) {
for (q = minq; q <= maxq; ++q) {
for (p = minp; p <= maxp; ++p) {
madd_v3_v3fl(vel_smooth, verts[kernel_offset].velocity, invD);
kernel_offset += 1;
}
kernel_offset += kernel_dq;
}
kernel_offset += kernel_dr;
}
}
void BPH_hair_volume_vertex_grid_filter_box(HairVertexGrid *grid, int kernel_size)
{
int size = hair_grid_size(grid->res);
int kernel_sizev[3] = {kernel_size, kernel_size, kernel_size};
int tot;
float invD;
int i, j, k;
if (kernel_size <= 0)
return;
tot = kernel_size * 2 + 1;
invD = 1.0f / (float)(tot*tot*tot);
/* clear values for convolution */
for (i = 0; i < size; ++i) {
zero_v3(grid->verts[i].velocity_smooth);
}
for (i = 0; i < grid->res; ++i) {
for (j = 0; j < grid->res; ++j) {
for (k = 0; k < grid->res; ++k) {
hair_volume_filter_box_convolute(grid, invD, kernel_sizev, i, j, k);
}
}
}
/* apply as new velocity */
for (i = 0; i < size; ++i) {
copy_v3_v3(grid->verts[i].velocity, grid->verts[i].velocity_smooth);
}
}
#endif
HairGrid *BPH_hair_volume_create_vertex_grid(float cellsize, const float gmin[3], const float gmax[3])
{
float scale;
float extent[3];
int resmin[3], resmax[3], res[3];
float gmin_margin[3], gmax_margin[3];
int size;
HairGrid *grid;
int i;
/* sanity check */
if (cellsize <= 0.0f)
cellsize = 1.0f;
scale = 1.0f / cellsize;
sub_v3_v3v3(extent, gmax, gmin);
for (i = 0; i < 3; ++i) {
resmin[i] = floor_int(gmin[i] * scale);
resmax[i] = floor_int(gmax[i] * scale) + 1;
/* add margin of 1 cell */
resmin[i] -= 1;
resmax[i] += 1;
res[i] = resmax[i] - resmin[i] + 1;
/* sanity check: avoid null-sized grid */
if (res[i] < 4) {
res[i] = 4;
resmax[i] = resmin[i] + 4;
}
/* sanity check: avoid too large grid size */
if (res[i] > MAX_HAIR_GRID_RES) {
res[i] = MAX_HAIR_GRID_RES;
resmax[i] = resmin[i] + MAX_HAIR_GRID_RES;
}
gmin_margin[i] = (float)resmin[i] * cellsize;
gmax_margin[i] = (float)resmax[i] * cellsize;
}
size = hair_grid_size(res);
grid = (HairGrid *)MEM_callocN(sizeof(HairGrid), "hair grid");
grid->res[0] = res[0];
grid->res[1] = res[1];
grid->res[2] = res[2];
copy_v3_v3(grid->gmin, gmin_margin);
copy_v3_v3(grid->gmax, gmax_margin);
grid->cellsize = cellsize;
grid->inv_cellsize = scale;
grid->verts = (HairGridVert *)MEM_callocN(sizeof(HairGridVert) * size, "hair voxel data");
return grid;
}
void BPH_hair_volume_free_vertex_grid(HairGrid *grid)
{
if (grid) {
if (grid->verts)
MEM_freeN(grid->verts);
MEM_freeN(grid);
}
}
void BPH_hair_volume_set_debug_value(HairGrid *grid, float debug1, float debug2, int debug3, int debug4)
{
grid->debug1 = debug1;
grid->debug2 = debug2;
grid->debug3 = debug3;
grid->debug4 = debug4;
}
void BPH_hair_volume_grid_geometry(HairGrid *grid, float *cellsize, int res[3], float gmin[3], float gmax[3])
{
if (cellsize) *cellsize = grid->cellsize;
if (res) copy_v3_v3_int(res, grid->res);
if (gmin) copy_v3_v3(gmin, grid->gmin);
if (gmax) copy_v3_v3(gmax, grid->gmax);
}
#if 0
static HairGridVert *hair_volume_create_collision_grid(ClothModifierData *clmd, lfVector *lX, unsigned int numverts)
{
int res = hair_grid_res;
int size = hair_grid_size(res);
HairGridVert *collgrid;
ListBase *colliders;
ColliderCache *col = NULL;
float gmin[3], gmax[3], scale[3];
/* 2.0f is an experimental value that seems to give good results */
float collfac = 2.0f * clmd->sim_parms->collider_friction;
unsigned int v = 0;
int i = 0;
hair_volume_get_boundbox(lX, numverts, gmin, gmax);
hair_grid_get_scale(res, gmin, gmax, scale);
collgrid = MEM_mallocN(sizeof(HairGridVert) * size, "hair collider voxel data");
/* initialize grid */
for (i = 0; i < size; ++i) {
zero_v3(collgrid[i].velocity);
collgrid[i].density = 0.0f;
}
/* gather colliders */
colliders = get_collider_cache(clmd->scene, NULL, NULL);
if (colliders && collfac > 0.0f) {
for (col = colliders->first; col; col = col->next) {
MVert *loc0 = col->collmd->x;
MVert *loc1 = col->collmd->xnew;
float vel[3];
float weights[8];
int di, dj, dk;
for (v=0; v < col->collmd->numverts; v++, loc0++, loc1++) {
int offset;
if (!hair_grid_point_valid(loc1->co, gmin, gmax))
continue;
offset = hair_grid_weights(res, gmin, scale, lX[v], weights);
sub_v3_v3v3(vel, loc1->co, loc0->co);
for (di = 0; di < 2; ++di) {
for (dj = 0; dj < 2; ++dj) {
for (dk = 0; dk < 2; ++dk) {
int voffset = offset + di + (dj + dk*res)*res;
int iw = di + dj*2 + dk*4;
collgrid[voffset].density += weights[iw];
madd_v3_v3fl(collgrid[voffset].velocity, vel, weights[iw]);
}
}
}
}
}
}
free_collider_cache(&colliders);
/* divide velocity with density */
for (i = 0; i < size; i++) {
float density = collgrid[i].density;
if (density > 0.0f)
mul_v3_fl(collgrid[i].velocity, 1.0f/density);
}
return collgrid;
}
#endif
bool BPH_hair_volume_get_texture_data(HairGrid *grid, VoxelData *vd)
{
int totres, i;
int depth;
vd->resol[0] = grid->res[0];
vd->resol[1] = grid->res[1];
vd->resol[2] = grid->res[2];
totres = hair_grid_size(grid->res);
if (vd->hair_type == TEX_VD_HAIRVELOCITY) {
depth = 4;
vd->data_type = TEX_VD_RGBA_PREMUL;
}
else {
depth = 1;
vd->data_type = TEX_VD_INTENSITY;
}
if (totres > 0) {
vd->dataset = (float *)MEM_mapallocN(sizeof(float) * depth * (totres), "hair volume texture data");
for (i = 0; i < totres; ++i) {
switch (vd->hair_type) {
case TEX_VD_HAIRDENSITY:
vd->dataset[i] = grid->verts[i].density;
break;
case TEX_VD_HAIRRESTDENSITY:
vd->dataset[i] = 0.0f; // TODO
break;
case TEX_VD_HAIRVELOCITY: {
vd->dataset[i + 0*totres] = grid->verts[i].velocity[0];
vd->dataset[i + 1*totres] = grid->verts[i].velocity[1];
vd->dataset[i + 2*totres] = grid->verts[i].velocity[2];
vd->dataset[i + 3*totres] = len_v3(grid->verts[i].velocity);
break;
}
case TEX_VD_HAIRENERGY:
vd->dataset[i] = 0.0f; // TODO
break;
}
}
}
else {
vd->dataset = NULL;
}
return true;
}
|