Commit: 782b89d861b76ba82d16dfdac0fbc8c041c7e0d0
Author: Bastien Montagne
Date: Wed Nov 12 16:20:51 2014 +0100
Branches: mesh-transfer-data
https://developer.blender.org/rB782b89d861b76ba82d16dfdac0fbc8c041c7e0d0
Replace grid-sampling by random tess-based one, for face's normal projection
sampled mapping method.
Based on review & suggestions from Campbell, many thanks.
This commit adds a new func to BLI_geom, `BLI_tri_v2_sample_random_point()`,
which uses
given 2D tri and random generator to generate a random point on that triangle.
===================================================================
M source/blender/blenkernel/intern/mesh_mapping.c
M source/blender/blenlib/BLI_math_geom.h
M source/blender/blenlib/intern/math_geom.c
===================================================================
diff --git a/source/blender/blenkernel/intern/mesh_mapping.c
b/source/blender/blenkernel/intern/mesh_mapping.c
index 9795e22..050c4cb 100644
--- a/source/blender/blenkernel/intern/mesh_mapping.c
+++ b/source/blender/blenkernel/intern/mesh_mapping.c
@@ -37,6 +37,8 @@
#include "BLI_bitmap.h"
#include "BLI_math.h"
#include "BLI_memarena.h"
+#include "BLI_polyfill2d.h"
+#include "BLI_rand.h"
#include "BKE_bvhutils.h"
#include "BKE_customdata.h"
@@ -1980,6 +1982,11 @@ void BKE_dm2mesh_mapping_polys_compute(
}
}
else if (mode == M2MMAP_MODE_POLY_POLYINTERP_PNORPROJ) {
+ /* We cast our rays randomly, with a pseudo-even
distribution (since we spread across tessellated tris,
+ * with additional weighting based on each tri's
relative area).
+ */
+ RNG *rng = BLI_rng_new(0);
+
const size_t numpolys_src =
(size_t)dm_src->getNumPolys(dm_src);
/* Here it's simpler to just allocate for all polys :/
*/
@@ -1988,6 +1995,8 @@ void BKE_dm2mesh_mapping_polys_compute(
size_t tmp_poly_size = 32; /* Will be enough in 99% of
cases. */
float (*poly_vcos_2d)[2] =
MEM_mallocN(sizeof(*poly_vcos_2d) * tmp_poly_size, __func__);
+ /* Tessellated 2D poly, always (num_loops - 2)
triangles. */
+ int (*tri_vidx_2d)[3] =
MEM_mallocN(sizeof(*tri_vidx_2d) * (tmp_poly_size - 2), __func__);
for (i = 0; i < numpolys_dst; i++) {
/* For each dst poly, we sample some rays from
it (2D grid in pnor space)
@@ -1996,18 +2005,20 @@ void BKE_dm2mesh_mapping_polys_compute(
MPoly *mp = &polys_dst[i];
float tmp_co[3], tmp_no[3];
- int grid_size;
+ int tot_rays, done_rays = 0;
+ float poly_area_2d_inv, done_area = 0.0f;
+
const float zvec[3] = {0.0f, 0.0f, 1.0f};
float pcent_dst[3];
float to_pnor_2d_mat[3][3],
from_pnor_2d_mat[3][3];
float poly_dst_2d_min[2], poly_dst_2d_max[2],
poly_dst_2d_z;
float poly_dst_2d_size[2];
- float grid_step[2];
float totweights = 0.0f;
float hitdist_accum = 0.0f;
int nbr_sources = 0;
- int j, k;
+ int nbr_tris = mp->totloop - 2;
+ int j;
BKE_mesh_calc_poly_center(mp,
&loops_dst[mp->loopstart], verts_dst, pcent_dst);
copy_v3_v3(tmp_no, poly_nors_dst[i]);
@@ -2022,6 +2033,7 @@ void BKE_dm2mesh_mapping_polys_compute(
if ((size_t)mp->totloop > tmp_poly_size) {
tmp_poly_size = (size_t)mp->totloop;
poly_vcos_2d =
MEM_reallocN(poly_vcos_2d, sizeof(*poly_vcos_2d) * tmp_poly_size);
+ tri_vidx_2d = MEM_reallocN(tri_vidx_2d,
sizeof(*tri_vidx_2d) * (tmp_poly_size - 2));
}
rotation_between_vecs_to_mat3(to_pnor_2d_mat,
tmp_no, zvec);
@@ -2047,25 +2059,53 @@ void BKE_dm2mesh_mapping_polys_compute(
* with lower/upper bounds. */
sub_v2_v2v2(poly_dst_2d_size, poly_dst_2d_max,
poly_dst_2d_min);
- grid_size = (int)((max_ff(poly_dst_2d_size[0],
poly_dst_2d_size[1]) / ray_radius) + 0.5f);
- CLAMP(grid_size, 4, 20); /* min 16 rays/face,
max 400. */
+ if (ray_radius) {
+ tot_rays =
(int)((max_ff(poly_dst_2d_size[0], poly_dst_2d_size[1]) / ray_radius) + 0.5f);
+ CLAMP(tot_rays, 4, 20); /* min 16
rays/face, max 400. */
+ }
+ else {
+ tot_rays = 20; /* If no radius (pure
rays), give max number of rays! */
+ }
+ tot_rays *= tot_rays;
- mul_v2_v2fl(grid_step, poly_dst_2d_size, 1.0f /
(float)grid_size);
+ poly_area_2d_inv = 1.0f / area_poly_v2((const
float(*)[2])poly_vcos_2d, (unsigned int)mp->totloop);
- /* And now we can cast all our rays, and see
what we get! */
- for (j = 0; j < grid_size; j++) {
- for (k = 0; k < grid_size; k++) {
+ /* Tessellate our poly. */
+ if (mp->totloop == 3) {
+ tri_vidx_2d[0][0] = 0;
+ tri_vidx_2d[0][1] = 1;
+ tri_vidx_2d[0][2] = 2;
+ }
+ if (mp->totloop == 4) {
+ tri_vidx_2d[0][0] = 0;
+ tri_vidx_2d[0][1] = 1;
+ tri_vidx_2d[0][2] = 2;
+ tri_vidx_2d[1][0] = 0;
+ tri_vidx_2d[1][1] = 2;
+ tri_vidx_2d[1][2] = 3;
+ }
+ else {
+ BLI_polyfill_calc((const
float(*)[2])poly_vcos_2d, (unsigned int)mp->totloop, -1,
+ (unsigned int
(*)[3])tri_vidx_2d);
+ }
+
+ for (j = 0; j < nbr_tris; j++) {
+ float *v1 =
poly_vcos_2d[tri_vidx_2d[j][0]];
+ float *v2 =
poly_vcos_2d[tri_vidx_2d[j][1]];
+ float *v3 =
poly_vcos_2d[tri_vidx_2d[j][2]];
+ int nbr_rays;
+
+ /* All this allows us to get 'absolute'
number of rays for each tri, avoiding accumulating
+ * errors over iterations, and helping
better even distribution. */
+ done_area += area_tri_v2(v1, v2, v3);
+ nbr_rays = (int)((float)tot_rays *
done_area * poly_area_2d_inv + 0.5f) - done_rays;
+ done_rays += nbr_rays;
+
+ while (nbr_rays--) {
int n = (ray_radius > 0.0f) ?
M2MMAP_RAYCAST_APPROXIMATE_NR : 1;
float w = 1.0f;
- tmp_co[0] = poly_dst_2d_min[0]
+ grid_step[0] * (float)j;
- tmp_co[1] = poly_dst_2d_min[1]
+ grid_step[1] * (float)k;
-
- if
(!isect_point_poly_v2(tmp_co, (const float (*)[2])poly_vcos_2d,
-
(unsigned int)mp->totloop, false))
- {
- continue;
- }
+
BLI_tri_v2_sample_random_point(v1, v2, v3, rng, tmp_co);
tmp_co[2] = poly_dst_2d_z;
mul_m3_v3(from_pnor_2d_mat,
tmp_co);
@@ -2087,6 +2127,7 @@ void BKE_dm2mesh_mapping_polys_compute(
}
}
}
+
if (totweights > 0.0f) {
for (j = 0; j < (int)numpolys_src; j++)
{
if (!weights[j]) {
@@ -2106,9 +2147,11 @@ void BKE_dm2mesh_mapping_polys_compute(
}
}
+ MEM_freeN(tri_vidx_2d);
MEM_freeN(poly_vcos_2d);
MEM_freeN(indices);
MEM_freeN(weights);
+ BLI_rng_free(rng);
}
else {
printf("WARNING! Unsupported mesh-to-mesh poly mapping
mode (%d)!\n", mode);
diff --git a/source/blender/blenlib/BLI_math_geom.h
b/source/blender/blenlib/BLI_math_geom.h
index ba32b29..1495ffa 100644
--- a/source/blender/blenlib/BLI_math_geom.h
+++ b/source/blender/blenlib/BLI_math_geom.h
@@ -42,6 +42,8 @@ extern "C" {
# pragma GCC diagnostic ignored "-Wredundant-decls"
#endif
+struct RNG;
+
/********************************** Polygons *********************************/
void cent_tri_v3(float r[3], const float a[3], const float b[3], const float
c[3]);
@@ -63,6 +65,8 @@ float cotangent_tri_weight_v3(const float v1[3], const float
v2[3], const float
MINLINE float cross_tri_v2(const float v1[2], const float v2[2], const float
v3[2]);
float cross_poly_v2(const float verts[][2], unsigned int nr);
+void BLI_tri_v2_sample_random_point(const float v1[2], const float v2[2],
const float v3[2], struct RNG *rng, float r_pt[2]);
+
/********************************* Planes **********************************/
void plane_from_point_normal_v3(float r_plane[4], const float plane_co[3],
const float plane_no[3]);
diff --git a/source/blender/blenlib/intern/math_geom.c
b/source/blender/blenlib/intern/math_geom.c
index 0153134..c50c3c6 100644
--- a/source/blender/blenlib/intern/math_geom.c
+++ b/source/blender/blenlib/intern/math_geom.c
@@ -31,6 +31,7 @@
#include "BLI_math.h"
#include "BLI_utildefines.h"
+#include "BLI_rand.h"
#include "BLI_strict_flags.h"
@@ -208,6 +209,29 @@ float cotangent_tri_weight_v3(const float v1[3], const
float v2[3], const float
}
}
+/**
+ * Generate a random point inside given tri.
+ */
+void BLI_tri_v2_sample_random_point(const float v1[2], const float v2[2],
const float v3[2], RNG *rng, float r_pt[2])
+{
+ float u = BLI_rng_get_float(rng);
+ float v = BLI_rng_get_float(rng);
+
+ float uside[2], vside[2];
+
+ if ((u + v) > 1.0f) {
+ u = 1.0f - u;
+ v = 1.0f - v;
+ }
+
+ sub_v2_v2v2(uside, v2, v1);
+ sub_v2_v2v2(vside, v3, v1);
+
+ copy_v2_v2(r_pt, v1);
+ madd_v2_v2fl(r_pt, uside, u);
+ madd_v2_v2fl(r_pt, vside, v);
+}
+
/********************************* Planes **********************************/
/**
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