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Partially replace convex hull implementation with Bullet implementation

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* Bullet's convex hull implementation is significantly more robust
  than the one I implemented, as well as being faster.

* This fixes bug [#32864] "Convex Hull fails in some cases."
  projects.blender.org/tracker/?func=detail&aid=32864&group_id=9&atid=498

  That bug, and others like it, relate to the poor handling of
  co-planar surfaces in the input. Pretty much any model that is
  simple-subdivided a few times gave very bad results before, Bullet's
  implementation handles this much better.

* In order to ensure a smooth transition, the Bullet output is
  translated into the existing HullTriangle hash structure. This makes
  it easy to ensure that the existing slot output stays the same; the
  interactions between the slots are somewhat complicated, detangling
  is a TODO.

* Reviewed by Brecht:
  https://codereview.appspot.com/6741063
This commit is contained in:
Nicholas Bishop
2012-10-23 23:54:15 +00:00
parent 0b16c9e201
commit 1dadd3b7c6
8 changed files with 159 additions and 321 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
source/blender/bmesh/CMakeLists.txt
View File

@@ -29,6 +29,7 @@ set(INC
../blenlib
../makesdna
../../../intern/guardedalloc
../../../extern/bullet2/src
)
set(INC_SYS
@@ -113,4 +114,8 @@ if(MSVC)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /WX")
endif()
if(WITH_BULLET)
add_definitions(-DWITH_BULLET)
endif()
blender_add_lib(bf_bmesh "${SRC}" "${INC}" "${INC_SYS}")

5
source/blender/bmesh/SConscript
View File

@@ -13,7 +13,12 @@ incs = [
'../makesdna',
'../blenkernel',
'#/intern/guardedalloc',
'#/extern/bullet2/src'
]
defs = []
if env['WITH_BF_BULLET']:
defs.append('WITH_BULLET')
env.BlenderLib ( libname = 'bf_bmesh', sources = sources, includes = Split(incs), libtype = ['core','player'], defines=defs, priority=[100, 100], compileflags=cflags )

4
source/blender/bmesh/intern/bmesh_opdefines.c
View File

@@ -1162,6 +1162,7 @@ static BMOpDefine bmo_slide_vert_def = {
BMO_OP_FLAG_UNTAN_MULTIRES
};
#ifdef WITH_BULLET
/*
* Convex Hull
*
@@ -1191,6 +1192,7 @@ static BMOpDefine bmo_convex_hull_def = {
bmo_convex_hull_exec,
0
};
#endif
/*
* Symmetrize
@@ -1227,7 +1229,9 @@ BMOpDefine *opdefines[] = {
&bmo_collapse_uvs_def,
&bmo_connect_verts_def,
&bmo_contextual_create_def,
#ifdef WITH_BULLET
&bmo_convex_hull_def,
#endif
&bmo_create_circle_def,
&bmo_create_cone_def,
&bmo_create_cube_def,

455
source/blender/bmesh/operators/bmo_hull.c
View File

@@ -24,19 +24,17 @@
* \ingroup bmesh
*/
#ifdef WITH_BULLET
#include "MEM_guardedalloc.h"
#include "BLI_array.h"
#include "BLI_ghash.h"
#include "BLI_listbase.h"
#include "BLI_math.h"
#include "BLI_utildefines.h"
/*XXX: This operator doesn't work well (at all?) for flat surfaces with
* >3 sides - creating overlapping faces at times.
* An easy workaround is to add in some noise but this is
* weak and unreliable, ideally this would detect flat surfaces
* (possibly making them into ngons) - see
*/
#include "Bullet-C-Api.h"
/* XXX: using 128 for totelem and pchunk of mempool, no idea what good
* values would be though */
@@ -46,21 +44,15 @@
#include "intern/bmesh_operators_private.h" /* own include */
#define HULL_EPSILON_FLT 0.0001f
/* values above 0.0001 cause errors, see below for details, don't increase
* without checking against bug [#32027] */
#define HULL_EPSILON_DOT_FLT 0.00000001f
/* Internal operator flags */
typedef enum {
HULL_FLAG_INPUT = (1 << 0),
HULL_FLAG_TETRA_VERT = (1 << 1),
HULL_FLAG_INTERIOR_ELE = (1 << 2),
HULL_FLAG_OUTPUT_GEOM = (1 << 3),
HULL_FLAG_INTERIOR_ELE = (1 << 1),
HULL_FLAG_OUTPUT_GEOM = (1 << 2),
HULL_FLAG_DEL = (1 << 4),
HULL_FLAG_HOLE = (1 << 5)
HULL_FLAG_DEL = (1 << 3),
HULL_FLAG_HOLE = (1 << 4)
} HullFlags;
/* Store hull triangles separate from BMesh faces until the end; this
@@ -72,63 +64,6 @@ typedef struct HullTriangle {
int skip;
} HullTriangle;
/* These edges define the hole created in the hull by deleting faces
* that can "see" a new vertex (the boundary edges then form the edge
* of a new triangle fan that has the new vertex as its center) */
typedef struct HullBoundaryEdge {
struct HullBoundaryEdge *next, *prev;
BMVert *v[2];
} HullBoundaryEdge;
/*************************** Boundary Edges ***************************/
static int edge_match(BMVert *e1_v1, BMVert *e1_v2, BMVert *e2[2])
{
return (e1_v1 == e2[0] && e1_v2 == e2[1]) ||
(e1_v1 == e2[1] && e1_v2 == e2[0]);
}
/* Returns true if the edge (e1, e2) is already in edges; that edge is
* deleted here as well. if not found just returns 0 */
static int check_for_dup(ListBase *edges, BLI_mempool *pool,
BMVert *v1, BMVert *v2)
{
HullBoundaryEdge *e, *e_next;
for (e = edges->first; e; e = e_next) {
e_next = e->next;
if (edge_match(v1, v2, e->v)) {
/* remove the interior edge */
BLI_remlink(edges, e);
BLI_mempool_free(pool, e);
return 1;
}
}
return 0;
}
static void expand_boundary_edges(ListBase *edges, BLI_mempool *edge_pool,
const HullTriangle *t)
{
HullBoundaryEdge *e_new;
int i;
/* Insert each triangle edge into the boundary list; if any of
* its edges are already in there, remove the edge entirely */
for (i = 0; i < 3; i++) {
if (!check_for_dup(edges, edge_pool, t->v[i], t->v[(i + 1) % 3])) {
e_new = BLI_mempool_calloc(edge_pool);
e_new->v[0] = t->v[i];
e_new->v[1] = t->v[(i + 1) % 3];
BLI_addtail(edges, e_new);
}
}
}
/*************************** Hull Triangles ***************************/
@@ -152,75 +87,6 @@ static void hull_add_triangle(BMesh *bm, GHash *hull_triangles, BLI_mempool *poo
normal_tri_v3(t->no, v1->co, v2->co, v3->co);
}
static int hull_point_tri_side(const HullTriangle *t, const float co[3])
{
/* Added epsilon to fix bug [#31941], improves output when some
* vertices are nearly coplanar. Might need further tweaking for
* other cases though.
* ...
* Update: epsilon of 0.0001 causes [#32027], use HULL_EPSILON_DOT_FLT
* and give it a much smaller value
* */
float p[3], d;
sub_v3_v3v3(p, co, t->v[0]->co);
d = dot_v3v3(t->no, p);
if (d < -HULL_EPSILON_DOT_FLT) return -1;
else if (d > HULL_EPSILON_DOT_FLT) return 1;
else return 0;
}
/* Get all hull triangles that vertex 'v' is outside of */
static GHash *hull_triangles_v_outside(GHash *hull_triangles, const BMVert *v)
{
GHash *outside;
GHashIterator iter;
outside = BLI_ghash_ptr_new("outside");
GHASH_ITER (iter, hull_triangles) {
HullTriangle *t = BLI_ghashIterator_getKey(&iter);
if (hull_point_tri_side(t, v->co) > 0)
BLI_ghash_insert(outside, t, NULL);
}
return outside;
}
/* For vertex 'v', find which triangles must be deleted to extend the
* hull; find the boundary edges of that hole so that it can be filled
* with connections to the new vertex, and update the hull_triangles
* to delete the marked triangles */
static void add_point(BMesh *bm, GHash *hull_triangles, BLI_mempool *hull_pool,
BLI_mempool *edge_pool, GHash *outside, BMVert *v)
{
ListBase edges = {NULL, NULL};
HullBoundaryEdge *e, *e_next;
GHashIterator iter;
GHASH_ITER (iter, outside) {
HullTriangle *t = BLI_ghashIterator_getKey(&iter);
int i;
expand_boundary_edges(&edges, edge_pool, t);
/* Mark triangle's vertices as interior */
for (i = 0; i < 3; i++)
BMO_elem_flag_enable(bm, t->v[i], HULL_FLAG_INTERIOR_ELE);
/* Delete the triangle */
BLI_ghash_remove(hull_triangles, t, NULL, NULL);
BLI_mempool_free(hull_pool, t);
}
/* Fill hole boundary with triangles to new point */
for (e = edges.first; e; e = e_next) {
e_next = e->next;
hull_add_triangle(bm, hull_triangles, hull_pool, e->v[0], e->v[1], v);
BLI_mempool_free(edge_pool, e);
}
}
static BMFace *hull_find_example_face(BMesh *bm, BMEdge *e)
{
BMIter iter;
@@ -362,158 +228,6 @@ static void hull_final_edges_free(HullFinalEdges *final_edges)
/************************* Initial Tetrahedron ************************/
static void hull_add_tetrahedron(BMesh *bm, GHash *hull_triangles, BLI_mempool *pool,
BMVert *tetra[4])
{
float center[3];
int i, indices[4][3] = {
{0, 1, 2},
{0, 2, 3},
{1, 0, 3},
{2, 1, 3}
};
/* Calculate center */
zero_v3(center);
for (i = 0; i < 4; i++)
add_v3_v3(center, tetra[i]->co);
mul_v3_fl(center, 0.25f);
for (i = 0; i < 4; i++) {
BMVert *v1 = tetra[indices[i][0]];
BMVert *v2 = tetra[indices[i][1]];
BMVert *v3 = tetra[indices[i][2]];
float no[3], d[3];
normal_tri_v3(no, v1->co, v2->co, v3->co);
sub_v3_v3v3(d, center, v1->co);
if (dot_v3v3(no, d) > 0)
SWAP(BMVert *, v1, v3);
hull_add_triangle(bm, hull_triangles, pool, v1, v2, v3);
}
}
/* For each axis, get the minimum and maximum input vertices */
static void hull_get_min_max(BMesh *bm, BMOperator *op,
BMVert *min[3], BMVert *max[3])
{
BMOIter oiter;
BMVert *v;
min[0] = min[1] = min[2] = NULL;
max[0] = max[1] = max[2] = NULL;
BMO_ITER (v, &oiter, bm, op, "input", BM_VERT) {
int i;
for (i = 0; i < 3; i++) {
if (!min[i] || v->co[i] < min[i]->co[i])
min[i] = v;
if (!max[i] || v->co[i] > max[i]->co[i])
max[i] = v;
}
}
}
/* Returns true if input is coplanar */
static int hull_find_large_tetrahedron(BMesh *bm, BMOperator *op,
BMVert *tetra[4])
{
BMVert *min[3], *max[3], *v;
BMOIter oiter;
float widest_axis_len, largest_dist, plane_normal[3];
int i, j, widest_axis;
tetra[0] = tetra[1] = tetra[2] = tetra[3] = NULL;
hull_get_min_max(bm, op, min, max);
/* Check for flat axis */
for (i = 0; i < 3; i++) {
if (min[i] == max[i]) {
return TRUE;
}
}
/* Find widest axis */
widest_axis_len = 0.0f;
widest_axis = 0; /* set here in the unlikey case this isn't set below */
for (i = 0; i < 3; i++) {
float len = (max[i]->co[i] - min[i]->co[i]);
if (len >= widest_axis_len) {
widest_axis_len = len;
widest_axis = i;
}
}
/* Use widest axis for first two points */
tetra[0] = min[widest_axis];
tetra[1] = max[widest_axis];
BMO_elem_flag_enable(bm, tetra[0], HULL_FLAG_TETRA_VERT);
BMO_elem_flag_enable(bm, tetra[1], HULL_FLAG_TETRA_VERT);
/* Choose third vertex farthest from existing line segment */
largest_dist = 0;
for (i = 0; i < 3; i++) {
BMVert *v;
float dist;
if (i == widest_axis)
continue;
v = min[i];
for (j = 0; j < 2; j++) {
dist = dist_to_line_segment_v3(v->co, tetra[0]->co, tetra[1]->co);
if (dist > largest_dist) {
largest_dist = dist;
tetra[2] = v;
}
v = max[i];
}
}
if (tetra[2]) {
BMO_elem_flag_enable(bm, tetra[2], HULL_FLAG_TETRA_VERT);
}
else {
return TRUE;
}
/* Check for colinear vertices */
if (largest_dist < HULL_EPSILON_FLT)
return TRUE;
/* Choose fourth point farthest from existing plane */
largest_dist = 0;
normal_tri_v3(plane_normal, tetra[0]->co, tetra[1]->co, tetra[2]->co);
BMO_ITER (v, &oiter, bm, op, "input", BM_VERT) {
if (!BMO_elem_flag_test(bm, v, HULL_FLAG_TETRA_VERT)) {
float dist = fabsf(dist_to_plane_v3(v->co, tetra[0]->co, plane_normal));
if (dist > largest_dist) {
largest_dist = dist;
tetra[3] = v;
}
}
}
if (tetra[3]) {
BMO_elem_flag_enable(bm, tetra[3], HULL_FLAG_TETRA_VERT);
}
else {
return TRUE;
}
if (largest_dist < HULL_EPSILON_FLT)
return TRUE;
return FALSE;
}
/**************************** Final Output ****************************/
static void hull_remove_overlapping(BMesh *bm, GHash *hull_triangles,
@@ -666,11 +380,132 @@ static void hull_tag_holes(BMesh *bm, BMOperator *op)
}
}
static int hull_input_vert_count(BMesh *bm, BMOperator *op)
{
BMOIter oiter;
BMVert *v;
int count = 0;
BMO_ITER (v, &oiter, bm, op, "input", BM_VERT) {
count++;
}
return count;
}
static BMVert **hull_input_verts_copy(BMesh *bm, BMOperator *op,
const int num_input_verts)
{
BMOIter oiter;
BMVert *v;
BMVert **input_verts = MEM_callocN(sizeof(*input_verts) *
num_input_verts, AT);
int i = 0;
BMO_ITER (v, &oiter, bm, op, "input", BM_VERT) {
input_verts[i++] = v;
}
return input_verts;
}
static float (*hull_verts_for_bullet(BMVert **input_verts,
const int num_input_verts))[3]
{
float (*coords)[3] = MEM_callocN(sizeof(*coords) * num_input_verts, AT);
int i;
for (i = 0; i < num_input_verts; i++) {
copy_v3_v3(coords[i], input_verts[i]->co);
}
return coords;
}
static BMVert **hull_verts_from_bullet(plConvexHull hull,
BMVert **input_verts,
const int num_input_verts)
{
const int num_verts = plConvexHullNumVertices(hull);
BMVert **hull_verts = MEM_mallocN(sizeof(*hull_verts) *
num_verts, AT);
int i;
for (i = 0; i < num_verts; i++) {
float co[3];
int original_index;
plConvexHullGetVertex(hull, i, co, &original_index);
if (original_index >= 0 && original_index < num_input_verts) {
hull_verts[i] = input_verts[original_index];
}
else
BLI_assert(!"Unexpected new vertex in hull output");
}
return hull_verts;
}
static void hull_from_bullet(BMesh *bm, BMOperator *op,
GHash *hull_triangles,
BLI_mempool *pool)
{
int *fvi = NULL;
BLI_array_declare(fvi);
BMVert **input_verts;
float (*coords)[3];
BMVert **hull_verts;
plConvexHull hull;
int i, count = 0;
const int num_input_verts = hull_input_vert_count(bm, op);
input_verts = hull_input_verts_copy(bm, op, num_input_verts);
coords = hull_verts_for_bullet(input_verts, num_input_verts);
hull = plConvexHullCompute(coords, num_input_verts);
hull_verts = hull_verts_from_bullet(hull, input_verts, num_input_verts);
count = plConvexHullNumFaces(hull);
for (i = 0; i < count; i++) {
const int len = plConvexHullGetFaceSize(hull, i);
if (len > 2) {
BMVert *fv[3];
int j;
/* Get face vertex indices */
BLI_array_empty(fvi);
BLI_array_grow_items(fvi, len);
plConvexHullGetFaceVertices(hull, i, fvi);
/* Note: here we throw away any NGons from Bullet and turn
* them into triangle fans. Would be nice to use these
* directly, but will have to wait until HullTriangle goes
* away (TODO) */
fv[0] = hull_verts[fvi[0]];
for (j = 2; j < len; j++) {
fv[1] = hull_verts[fvi[j - 1]];
fv[2] = hull_verts[fvi[j]];
hull_add_triangle(bm, hull_triangles, pool,
fv[0], fv[1], fv[2]);
}
}
}
BLI_array_free(fvi);
MEM_freeN(hull_verts);
MEM_freeN(coords);
MEM_freeN(input_verts);
}
void bmo_convex_hull_exec(BMesh *bm, BMOperator *op)
{
HullFinalEdges *final_edges;
BLI_mempool *hull_pool, *edge_pool;
BMVert *v, *tetra[4];
BLI_mempool *hull_pool;
BMElemF *ele;
BMOIter oiter;
GHash *hull_triangles;
@@ -682,15 +517,6 @@ void bmo_convex_hull_exec(BMesh *bm, BMOperator *op)
return;
}
/* Initialize the convex hull by building a tetrahedron. A
* degenerate tetrahedron can cause problems, so report error and
* fail if the result is coplanar */
if (hull_find_large_tetrahedron(bm, op, tetra)) {
BMO_error_raise(bm, op, BMERR_CONVEX_HULL_FAILED,
"Input vertices are coplanar");
return;
}
/* Tag input elements */
BMO_ITER (ele, &oiter, bm, op, "input", BM_ALL) {
BMO_elem_flag_enable(bm, ele, HULL_FLAG_INPUT);
@@ -700,26 +526,11 @@ void bmo_convex_hull_exec(BMesh *bm, BMOperator *op)
BMO_elem_flag_enable(bm, ele, HULL_FLAG_INTERIOR_ELE);
}
edge_pool = BLI_mempool_create(sizeof(HullBoundaryEdge), 128, 128, 0);
hull_pool = BLI_mempool_create(sizeof(HullTriangle), 128, 128, 0);
hull_triangles = BLI_ghash_ptr_new("hull_triangles");
/* Add tetrahedron triangles */
hull_add_tetrahedron(bm, hull_triangles, hull_pool, tetra);
hull_from_bullet(bm, op, hull_triangles, hull_pool);
/* Expand hull to cover new vertices outside the existing hull */
BMO_ITER (v, &oiter, bm, op, "input", BM_VERT) {
if (!BMO_elem_flag_test(bm, v, HULL_FLAG_TETRA_VERT)) {
GHash *outside = hull_triangles_v_outside(hull_triangles, v);
if (BLI_ghash_size(outside)) {
/* Expand hull and delete interior triangles */
add_point(bm, hull_triangles, hull_pool, edge_pool, outside, v);
}
BLI_ghash_free(outside, NULL, NULL);
}
}
BLI_mempool_destroy(edge_pool);
final_edges = hull_final_edges(hull_triangles);
hull_mark_interior_elements(bm, op, final_edges);
@@ -762,3 +573,5 @@ void bmo_convex_hull_exec(BMesh *bm, BMOperator *op)
BMO_slot_buffer_from_enabled_flag(bm, op, "geomout", BM_ALL,
HULL_FLAG_OUTPUT_GEOM);
}
#endif /* WITH_BULLET */

4
source/blender/editors/mesh/CMakeLists.txt
View File

@@ -73,4 +73,8 @@ if(WITH_INTERNATIONAL)
add_definitions(-DWITH_INTERNATIONAL)
endif()
if(WITH_BULLET)
add_definitions(-DWITH_BULLET)
endif()
blender_add_lib(bf_editor_mesh "${SRC}" "${INC}" "${INC_SYS}")

3
source/blender/editors/mesh/SConscript
View File

@@ -27,4 +27,7 @@ else:
if env['WITH_BF_INTERNATIONAL']:
defs.append('WITH_INTERNATIONAL')
if env['WITH_BF_BULLET']:
defs.append('WITH_BULLET')
env.BlenderLib ( 'bf_editors_mesh', sources, Split(incs), defs, libtype=['core'], priority=[45] )

2
source/blender/editors/mesh/editmesh_tools.c
View File

@@ -5389,6 +5389,7 @@ void MESH_OT_wireframe(wmOperatorType *ot)
RNA_def_boolean(ot->srna, "use_replace", TRUE, "Replace", "Remove original faces");
}
#ifdef WITH_BULLET
static int edbm_convex_hull_exec(bContext *C, wmOperator *op)
{
Object *obedit = CTX_data_edit_object(C);
@@ -5482,6 +5483,7 @@ void MESH_OT_convex_hull(wmOperatorType *ot)
join_triangle_props(ot);
}
#endif
static int mesh_symmetrize_exec(bContext *C, wmOperator *op)
{

2
source/blender/editors/mesh/mesh_ops.c
View File

@@ -165,7 +165,9 @@ void ED_operatortypes_mesh(void)
WM_operatortype_append(MESH_OT_wireframe);
WM_operatortype_append(MESH_OT_edge_split);
#ifdef WITH_BULLET
WM_operatortype_append(MESH_OT_convex_hull);
#endif
WM_operatortype_append(MESH_OT_symmetrize);