From e648542872a4887cd9f6c88501403033482df8ee Mon Sep 17 00:00:00 2001 From: Campbell Barton Date: Fri, 19 Oct 2012 07:31:51 +0000 Subject: [PATCH] decimate modifier rewrite to use bmesh (#ifdef-disabled by default for now). - maintains quads & ngons - supports some customdata (weight paint for example works fine). TODO - add suppory for loop data (UV's / VCol's). - outputs invalid geometry when heavily reducing some meshes, needs to be made stable in these cases. --- source/blender/bmesh/CMakeLists.txt | 2 + source/blender/bmesh/bmesh.h | 1 + source/blender/bmesh/intern/bmesh_decimate.c | 574 +++++++++++++++++++ source/blender/bmesh/intern/bmesh_decimate.h | 32 ++ 4 files changed, 609 insertions(+) create mode 100644 source/blender/bmesh/intern/bmesh_decimate.c create mode 100644 source/blender/bmesh/intern/bmesh_decimate.h diff --git a/source/blender/bmesh/CMakeLists.txt b/source/blender/bmesh/CMakeLists.txt index 20387684b66..1e56314ab6e 100644 --- a/source/blender/bmesh/CMakeLists.txt +++ b/source/blender/bmesh/CMakeLists.txt @@ -64,6 +64,8 @@ set(SRC intern/bmesh_construct.h intern/bmesh_core.c intern/bmesh_core.h + intern/bmesh_decimate.c + intern/bmesh_decimate.h intern/bmesh_inline.h intern/bmesh_interp.c intern/bmesh_interp.h diff --git a/source/blender/bmesh/bmesh.h b/source/blender/bmesh/bmesh.h index 955b1a729c5..a672ec0b6a7 100644 --- a/source/blender/bmesh/bmesh.h +++ b/source/blender/bmesh/bmesh.h @@ -252,6 +252,7 @@ extern "C" { #include "intern/bmesh_construct.h" #include "intern/bmesh_core.h" +#include "intern/bmesh_decimate.h" #include "intern/bmesh_interp.h" #include "intern/bmesh_iterators.h" #include "intern/bmesh_marking.h" diff --git a/source/blender/bmesh/intern/bmesh_decimate.c b/source/blender/bmesh/intern/bmesh_decimate.c new file mode 100644 index 00000000000..d8aa8adef55 --- /dev/null +++ b/source/blender/bmesh/intern/bmesh_decimate.c @@ -0,0 +1,574 @@ +/* + * ***** 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. + * + * Contributor(s): Campbell Barton + * + * ***** END GPL LICENSE BLOCK ***** + */ + +/** \file blender/bmesh/intern/bmesh_decimate.c + * \ingroup bmesh + * + * BMesh decimator. + */ + +#include + +#include "MEM_guardedalloc.h" + +#include "DNA_scene_types.h" + +#include "BLI_math.h" +#include "BLI_quadric.h" +#include "BLI_heap.h" + +#include "bmesh.h" +#include "bmesh_structure.h" +#include "bmesh_decimate.h" + +/* defines for testing */ +#define USE_CUSTOMDATA +#define USE_TRIANGULATE + +/* these checks are for rare cases that we can't avoid since they are valid meshes still */ +#define USE_SAFETY_CHECKS + +#define BOUNDARY_PRESERVE_WEIGHT 100.0f + + +/* BMesh Helper Functions + * ********************** */ + +/** + * \param vquadrics must be calloc'd + */ +static void bm_decim_build_quadrics(BMesh *bm, Quadric *vquadrics) +{ + BMIter iter; + BMFace *f; + BMEdge *e; + + BM_ITER_MESH (f, &iter, bm, BM_FACES_OF_MESH) { + BMLoop *l_first; + BMLoop *l_iter; + + const float *co = BM_FACE_FIRST_LOOP(f)->v->co; + const float *no = f->no; + const float offset = -dot_v3v3(no, co); + Quadric q; + + BLI_quadric_from_v3_dist(&q, no, offset); + + l_iter = l_first = BM_FACE_FIRST_LOOP(f); + do { + BLI_quadric_add_qu_qu(&vquadrics[BM_elem_index_get(l_iter->v)], &q); + } while ((l_iter = l_iter->next) != l_first); + } + + /* boundary edges */ + BM_ITER_MESH (e, &iter, bm, BM_EDGES_OF_MESH) { + if (UNLIKELY(BM_edge_is_boundary(e))) { + float edge_vector[3]; + float edge_cross[3]; + sub_v3_v3v3(edge_vector, e->v2->co, e->v1->co); + f = e->l->f; + cross_v3_v3v3(edge_cross, edge_vector, f->no); + + if (normalize_v3(edge_cross) != 0.0f) { + Quadric q; + BLI_quadric_from_v3_dist(&q, edge_vector, -dot_v3v3(edge_cross, e->v1->co)); + BLI_quadric_mul(&q, BOUNDARY_PRESERVE_WEIGHT); + + BLI_quadric_add_qu_qu(&vquadrics[BM_elem_index_get(e->v1)], &q); + BLI_quadric_add_qu_qu(&vquadrics[BM_elem_index_get(e->v2)], &q); + } + } + } +} + + +static void bm_decim_calc_target_co(BMEdge *e, float optimize_co[3], + const Quadric *vquadrics) +{ + /* compute an edge contration target for edge ei + * this is computed by summing it's vertices quadrics and + * optimizing the result. */ + Quadric q; + + BLI_quadric_add_qu_ququ(&q, + &vquadrics[BM_elem_index_get(e->v1)], + &vquadrics[BM_elem_index_get(e->v2)]); + + + if (BLI_quadric_optimize(&q, optimize_co)) { + return; /* all is good */ + } + else { + mid_v3_v3v3(optimize_co, e->v1->co, e->v2->co); + } +} + +static void bm_decim_build_edge_cost_single(BMEdge *e, + const Quadric *vquadrics, + Heap *eheap, HeapNode **eheap_table) +{ + const Quadric *q1, *q2; + float optimize_co[3]; + float cost; + + if (eheap_table[BM_elem_index_get(e)]) { + BLI_heap_remove(eheap, eheap_table[BM_elem_index_get(e)]); + } + + /* check we can collapse, some edges we better not touch */ + if (BM_edge_is_boundary(e)) { + if (e->l->f->len == 3) { + /* pass */ + } + else { + /* only collapse tri's */ + eheap_table[BM_elem_index_get(e)] = NULL; + return; + } + } + else if (BM_edge_is_manifold(e)) { + if ((e->l->f->len == 3) && (e->l->radial_next->f->len == 3)) { + /* pass */ + } + else { + /* only collapse tri's */ + eheap_table[BM_elem_index_get(e)] = NULL; + return; + } + } + else { + eheap_table[BM_elem_index_get(e)] = NULL; + return; + } + /* end sanity check */ + + + bm_decim_calc_target_co(e, optimize_co, vquadrics); + + q1 = &vquadrics[BM_elem_index_get(e->v1)]; + q2 = &vquadrics[BM_elem_index_get(e->v2)]; + + cost = (BLI_quadric_evaluate(q1, optimize_co) + BLI_quadric_evaluate(q2, optimize_co)); + + eheap_table[BM_elem_index_get(e)] = BLI_heap_insert(eheap, cost, e); +} + +static void bm_decim_build_edge_cost(BMesh *bm, + const Quadric *vquadrics, + Heap *eheap, HeapNode **eheap_table) +{ + BMIter iter; + BMEdge *e; + unsigned int i; + + BM_ITER_MESH_INDEX (e, &iter, bm, BM_EDGES_OF_MESH, i) { + eheap_table[i] = NULL; /* keep sanity check happy */ + bm_decim_build_edge_cost_single(e, vquadrics, eheap, eheap_table); + } +} + +#ifdef USE_TRIANGULATE +/* Temp Triangulation + * ****************** */ + +/** + * To keep things simple we can only collapse edges on triangulated data + * (limitation with edge collapse and error calculation functions). + * + * But to avoid annoying users by only giving triangle results, we can + * triangulate, keeping a reference between the faces, then join after + * if the edges don't collapse, this will also allow more choices when + * collapsing edges so even has some advantage over decimating quads + * directly. + * + * \return TRUE if any faces were triangulated. + */ + +static int bm_decim_triangulate_begin(BMesh *bm) +{ +#ifdef USE_SAFETY_CHECKS + const int check_double_edges = TRUE; +#else + const int check_double_edges = FALSE; +#endif + + BMIter iter; + BMFace *f; + // int has_quad; // could optimize this a little + int has_cut = FALSE; + + BLI_assert((bm->elem_index_dirty & BM_VERT) == 0); + + /* first clear loop index values */ + BM_ITER_MESH (f, &iter, bm, BM_FACES_OF_MESH) { + BMLoop *l_iter; + BMLoop *l_first; + + l_iter = l_first = BM_FACE_FIRST_LOOP(f); + do { + BM_elem_index_set(l_iter, -1); + } while ((l_iter = l_iter->next) != l_first); + + // has_quad |= (f->len == 4) + } + + /* adding new faces as we loop over faces + * is normally best avoided, however in this case its not so bad because any face touched twice + * will already be triangulated*/ + BM_ITER_MESH (f, &iter, bm, BM_FACES_OF_MESH) { + if (f->len == 4) { + BMLoop *f_l[4]; + BMLoop *l_iter; + BMLoop *l_a, *l_b; + + l_iter = BM_FACE_FIRST_LOOP(f); + + f_l[0] = l_iter; l_iter = l_iter->next; + f_l[1] = l_iter; l_iter = l_iter->next; + f_l[2] = l_iter; l_iter = l_iter->next; + f_l[3] = l_iter; l_iter = l_iter->next; + + if (len_squared_v3v3(f_l[0]->v->co, f_l[2]->v->co) < len_squared_v3v3(f_l[1]->v->co, f_l[3]->v->co)) { + l_a = f_l[0]; + l_b = f_l[2]; + } + else { + l_a = f_l[1]; + l_b = f_l[3]; + } + + { + BMFace *f_new; + BMLoop *l_new; + + /* warning, NO_DOUBLE option here isn't handled as nice as it could be + * - if there is a quad that has a free standing edge joining it along + * where we want to split the face, there isnt a good way we can handle this. + * currently that edge will get removed when joining the tris back into a quad. */ + f_new = BM_face_split(bm, f, l_a->v, l_b->v, &l_new, NULL, check_double_edges); + + if (f_new) { + /* the value of this doesn't matter, only that the 2 loops match and have unique values */ + const int f_index = BM_elem_index_get(f); + + /* since we just split theres only ever 2 loops */ + BLI_assert(BM_edge_is_manifold(l_new->e)); + + BM_elem_index_set(l_new, f_index); + BM_elem_index_set(l_new->radial_next, f_index); + + has_cut = TRUE; + } + } + } + } + + BLI_assert((bm->elem_index_dirty & BM_VERT) == 0); + + if (has_cut) { + /* now triangulation is done we need to correct index values */ + BM_mesh_elem_index_ensure(bm, BM_EDGE | BM_FACE); + } + + return has_cut; +} + +static void bm_decim_triangulate_end(BMesh *bm) +{ + /* decimation finished, now re-join */ + BMIter iter; + BMEdge *e; + + /* boundary edges */ + BM_ITER_MESH (e, &iter, bm, BM_EDGES_OF_MESH) { + BMLoop *l_a, *l_b; + if (BM_edge_loop_pair(e, &l_a, &l_b)) { + const int l_a_index = BM_elem_index_get(l_a); + if (l_a_index != -1) { + const int l_b_index = BM_elem_index_get(l_b); + if (l_a_index == l_b_index) { + /* highly unlikely to fail, but prevents possible double-ups */ + if (l_a->f->len == 3 && l_b->f->len == 3) { + BMFace *f[2] = {l_a->f, l_b->f}; + BM_faces_join(bm, f, 2, TRUE); + } + } + } + } + } +} + +#endif /* USE_TRIANGULATE */ + +/* Edge Collapse Functions + * *********************** */ + +/** + * special, highly limited edge collapse function + * intended for speed over flexibiliy. + * can only collapse edges connected to (1, 2) tris. + * + * Important - dont add vert/edge/face data on collapsing! + * + * \param ke_other let caller know what edges we remove besides \a ke + */ +static int bm_edge_collapse(BMesh *bm, BMEdge *ke, BMVert *kv, int ke_other[2], +#ifdef USE_CUSTOMDATA + const float customdata_fac +#else + const float UNUSED(customdata_fac) +#endif + ) +{ + BMVert *v_other = BM_edge_other_vert(ke, kv); + + BLI_assert(v_other != NULL); + + if (BM_edge_is_manifold(ke)) { + BMLoop *l_a, *l_b; + BMEdge *e_a_other[2], *e_b_other[2]; + int ok; + + ok = BM_edge_loop_pair(ke, &l_a, &l_b); + + BLI_assert(ok == TRUE); + BLI_assert(l_a->f->len == 3); + BLI_assert(l_b->f->len == 3); + + /* keep 'kv' 0th */ + if (BM_vert_in_edge(l_a->prev->e, kv)) { + e_a_other[0] = l_a->prev->e; + e_a_other[1] = l_a->next->e; + } + else { + e_a_other[1] = l_a->prev->e; + e_a_other[0] = l_a->next->e; + } + + if (BM_vert_in_edge(l_b->prev->e, kv)) { + e_b_other[0] = l_b->prev->e; + e_b_other[1] = l_b->next->e; + } + else { + e_b_other[1] = l_b->prev->e; + e_b_other[0] = l_b->next->e; + } + + BLI_assert(BM_edge_share_vert(e_a_other[0], e_b_other[0])); + BLI_assert(BM_edge_share_vert(e_a_other[1], e_b_other[1])); + + /* we could assert this case, but better just bail out */ +#if 0 + BLI_assert(e_a_other[0] != e_b_other[0]); + BLI_assert(e_a_other[0] != e_b_other[1]); + BLI_assert(e_b_other[0] != e_a_other[0]); + BLI_assert(e_b_other[0] != e_a_other[1]); +#endif + /* not totally common but we want to avoid */ + if (ELEM(e_a_other[0], e_b_other[0], e_b_other[1]) || + ELEM(e_a_other[1], e_b_other[0], e_b_other[1])) + { + return FALSE; + } + + ke_other[0] = BM_elem_index_get(e_a_other[0]); + ke_other[1] = BM_elem_index_get(e_b_other[0]); + +#ifdef USE_CUSTOMDATA + /* TODO, loops */ + // const float w[2] = {customdata_fac, 1.0f - customdata_fac}; + + /* before killing, do customdata */ + BM_data_interp_from_verts(bm, v_other, kv, v_other, customdata_fac); +#endif + + BM_edge_kill(bm, ke); + + BM_vert_splice(bm, kv, v_other); + + BM_edge_splice(bm, e_a_other[0], e_a_other[1]); + BM_edge_splice(bm, e_b_other[0], e_b_other[1]); + + // BM_mesh_validate(bm); + + return TRUE; + } + else if (BM_edge_is_boundary(ke)) { + /* same as above but only one triangle */ + BMLoop *l_a; + BMEdge *e_a_other[2]; + + l_a = ke->l; + + BLI_assert(l_a->f->len == 3); + + /* keep 'kv' 0th */ + if (BM_vert_in_edge(l_a->prev->e, kv)) { + e_a_other[0] = l_a->prev->e; + e_a_other[1] = l_a->next->e; + } + else { + e_a_other[1] = l_a->prev->e; + e_a_other[0] = l_a->next->e; + } + + ke_other[0] = BM_elem_index_get(e_a_other[0]); + ke_other[1] = -1; + +#ifdef USE_CUSTOMDATA + /* TODO, loops */ + // const float w[2] = {customdata_fac, 1.0f - customdata_fac}; + + /* before killing, do customdata */ + BM_data_interp_from_verts(bm, v_other, kv, v_other, customdata_fac); +#endif + + BM_edge_kill(bm, ke); + + BM_vert_splice(bm, kv, v_other); + + BM_edge_splice(bm, e_a_other[0], e_a_other[1]); + + // BM_mesh_validate(bm); + + return TRUE; + } + else { + return FALSE; + } +} + + +/* collapse e the edge, removing e->v2 */ +static void bm_decim_edge_collapse(BMesh *bm, BMEdge *e, + Quadric *vquadrics, + Heap *eheap, HeapNode **eheap_table) +{ + int ke_other[2]; + BMVert *v = e->v1; + int kv_index = BM_elem_index_get(e->v2); /* the vert is removed so only store the index */ + float optimize_co[3]; + float customdata_fac; + + bm_decim_calc_target_co(e, optimize_co, vquadrics); + + /* use for customdata merging */ + customdata_fac = line_point_factor_v3(optimize_co, e->v1->co, e->v2->co); + + if (bm_edge_collapse(bm, e, e->v2, ke_other, customdata_fac)) { + /* update collapse info */ + int i; + + e = NULL; /* paranoid safety check */ + + copy_v3_v3(v->co, optimize_co); + + /* remove eheap */ + for (i = 0; i < 2; i++) { + /* highly unlikely 'eheap_table[ke_other[i]]' would be NULL, but do for sanity sake */ + if ((ke_other[i] != -1) && (eheap_table[ke_other[i]] != NULL)) { + BLI_heap_remove(eheap, eheap_table[ke_other[i]]); + eheap_table[ke_other[i]] = NULL; + } + } + + /* update vertex quadric, add kept vertex from killed vertex */ + BLI_quadric_add_qu_qu(&vquadrics[BM_elem_index_get(v)], &vquadrics[kv_index]); + + /* update connected normals */ + BM_vert_normal_update_all(v); + + /* update error costs and the eheap */ + if (LIKELY(v->e)) { + BMEdge *e_iter; + BMEdge *e_first; + e_iter = e_first = v->e; + do { + bm_decim_build_edge_cost_single(e_iter, vquadrics, eheap, eheap_table); + } while ((e_iter = bmesh_disk_edge_next(e_iter, v)) != e_first); + } + } +} + + +/* Main Decimate Function + * ********************** */ + +void BM_mesh_decimate(BMesh *bm, const float factor) +{ + Heap *eheap; /* edge heap */ + HeapNode **eheap_table; /* edge index aligned table pointing to the eheap */ + Quadric *vquadrics; /* vert index aligned quadrics */ + int tot_edge_orig; + int face_tot_target; + int use_triangulate; + + +#ifdef USE_TRIANGULATE + /* temp convert quads to triangles */ + use_triangulate = bm_decim_triangulate_begin(bm); +#endif + + + /* alloc vars */ + vquadrics = MEM_callocN(sizeof(Quadric) * bm->totvert, __func__); + eheap = BLI_heap_new(); + eheap_table = MEM_callocN(sizeof(HeapNode *) * bm->totedge, __func__); + tot_edge_orig = bm->totedge; + + + /* build initial edge collapse cost data */ + bm_decim_build_quadrics(bm, vquadrics); + + bm_decim_build_edge_cost(bm, vquadrics, eheap, eheap_table); + + face_tot_target = bm->totface * factor; + bm->elem_index_dirty |= BM_FACE | BM_EDGE | BM_VERT; + + + /* iterative edge collapse and maintain the eheap */ + while ((bm->totface > face_tot_target) && (BLI_heap_empty(eheap) == FALSE)) { + BMEdge *e = BLI_heap_popmin(eheap); + BLI_assert(BM_elem_index_get(e) < tot_edge_orig); /* handy to detect corruptions elsewhere */ + + /* under normal conditions wont be accessed again, + * but NULL just incase so we don't use freed node */ + eheap_table[BM_elem_index_get(e)] = NULL; + + bm_decim_edge_collapse(bm, e, vquadrics, eheap, eheap_table); + } + + +#ifdef USE_TRIANGULATE + /* its possible we only had triangles, skip this step in that case */ + if (LIKELY(use_triangulate)) { + /* temp convert quads to triangles */ + bm_decim_triangulate_end(bm); + } +#endif + + + /* free vars */ + MEM_freeN(vquadrics); + MEM_freeN(eheap_table); + BLI_heap_free(eheap, NULL); +} diff --git a/source/blender/bmesh/intern/bmesh_decimate.h b/source/blender/bmesh/intern/bmesh_decimate.h new file mode 100644 index 00000000000..e44aa576bda --- /dev/null +++ b/source/blender/bmesh/intern/bmesh_decimate.h @@ -0,0 +1,32 @@ +/* + * ***** 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. + * + * Contributor(s): Campbell Barton + * + * ***** END GPL LICENSE BLOCK ***** + */ + +#ifndef __BMESH_DECIMATE_H__ +#define __BMESH_DECIMATE_H__ + +/** \file blender/bmesh/intern/bmesh_decimate.h + * \ingroup bmesh + */ + +void BM_mesh_decimate(BMesh *bm, const float factor); + +#endif /* __BMESH_DECIMATE_H__ */