[Bf-blender-cvs] [770bcfac9b0] geometry-nodes: Geometry Nodes: improve point distribute node
Jacques Lucke
noreply at git.blender.org
Thu Nov 12 13:31:12 CET 2020
Commit: 770bcfac9b007bc5e99001d6acdad434f6e1dc8b
Author: Jacques Lucke
Date: Thu Nov 12 13:24:46 2020 +0100
Branches: geometry-nodes
https://developer.blender.org/rB770bcfac9b007bc5e99001d6acdad434f6e1dc8b
Geometry Nodes: improve point distribute node
* Support vertex weights to control density.
* O(n) performance instead of O(n^2).
* More stable when density weights are changed.
The vertex group has to be specified using an index for now.
This is a technical limitation that will resolved a bit later.
===================================================================
M source/blender/nodes/geometry/nodes/node_geo_point_distribute.cc
===================================================================
diff --git a/source/blender/nodes/geometry/nodes/node_geo_point_distribute.cc b/source/blender/nodes/geometry/nodes/node_geo_point_distribute.cc
index 2c700248ed3..bc3136ce348 100644
--- a/source/blender/nodes/geometry/nodes/node_geo_point_distribute.cc
+++ b/source/blender/nodes/geometry/nodes/node_geo_point_distribute.cc
@@ -15,6 +15,7 @@
*/
#include "BLI_float3.hh"
+#include "BLI_hash.h"
#include "BLI_math_vector.h"
#include "BLI_rand.hh"
#include "BLI_span.hh"
@@ -23,6 +24,7 @@
#include "DNA_meshdata_types.h"
#include "DNA_pointcloud_types.h"
+#include "BKE_deform.h"
#include "BKE_mesh.h"
#include "BKE_mesh_runtime.h"
#include "BKE_pointcloud.h"
@@ -32,7 +34,8 @@
static bNodeSocketTemplate geo_node_point_distribute_in[] = {
{SOCK_GEOMETRY, N_("Geometry")},
{SOCK_FLOAT, N_("Density"), 10.0f, 0.0f, 0.0f, 0.0f, 0.0f, 100000.0f, PROP_NONE},
- {SOCK_FLOAT, N_("Minimum Radius"), 10.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1000.0f, PROP_NONE},
+ /* Use an index, because the vertex group names are not available in the mesh... */
+ {SOCK_INT, N_("Density Attribute Index"), -1, 0, 0, 0, -1, 1000},
{-1, ""},
};
@@ -41,87 +44,63 @@ static bNodeSocketTemplate geo_node_point_distribute_out[] = {
{-1, ""},
};
-static void mesh_loop_tri_corner_coords(
- const Mesh *mesh, const int index, float **r_v0, float **r_v1, float **r_v2)
-{
- MVert *mverts = mesh->mvert;
- MLoop *mloops = mesh->mloop;
-
- MLoopTri looptri = mesh->runtime.looptris.array[index];
- const MLoop *mloop_0 = &mloops[looptri.tri[0]];
- const MLoop *mloop_1 = &mloops[looptri.tri[1]];
- const MLoop *mloop_2 = &mloops[looptri.tri[2]];
- *r_v0 = mverts[mloop_0->v].co;
- *r_v1 = mverts[mloop_1->v].co;
- *r_v2 = mverts[mloop_2->v].co;
-}
-
-using blender::float3;
+namespace blender::nodes {
-static PointCloud *scatter_pointcloud_from_mesh(const Mesh *mesh,
- const float density,
- const float UNUSED(minimum_radius))
+static Vector<float3> scatter_points_from_mesh(const Mesh *mesh,
+ const float density,
+ const int density_attribute_index)
{
/* This only updates a cache and can be considered to be logically const. */
- BKE_mesh_runtime_looptri_ensure(const_cast<Mesh *>(mesh));
- const int looptris_len = mesh->runtime.looptris.len;
- blender::Array<float> weights(looptris_len);
-
- /* Calculate area for every triangle and the total area for the whole mesh. */
- float area_total = 0.0f;
- for (int i = 0; i < looptris_len; i++) {
- float *v0, *v1, *v2;
- mesh_loop_tri_corner_coords(mesh, i, &v0, &v1, &v2);
- const float tri_area = area_tri_v3(v0, v1, v2);
-
- weights[i] = tri_area;
- area_total += tri_area;
- }
+ const MLoopTri *looptris = BKE_mesh_runtime_looptri_ensure(const_cast<Mesh *>(mesh));
+ const int looptris_len = BKE_mesh_runtime_looptri_len(mesh);
- /* Fill an array with the sums of each weight. No need to normalize by the area of the largest
- * triangle since it's all relative anyway. Reuse the orginal weights array to avoid allocating
- * another.
- *
- * TODO: Multiply by a vertex group / attribute here as well. */
- float weight_total = 0.0f;
- for (int i = 0; i < looptris_len; i++) {
- weight_total += weights[i];
- weights[i] = weight_total;
+ Array<float> vertex_density_factors(mesh->totvert);
+ if (density_attribute_index == -1) {
+ vertex_density_factors.fill(1.0f);
+ }
+ else {
+ MDeformVert *dverts = mesh->dvert;
+ BKE_defvert_extract_vgroup_to_vertweights(
+ dverts, density_attribute_index, mesh->totvert, vertex_density_factors.data(), false);
}
- /* Calculate the total number of points and create the pointcloud. */
- const int points_len = round_fl_to_int(area_total * density);
- PointCloud *pointcloud = BKE_pointcloud_new_nomain(points_len);
-
- /* Distribute the points. */
- blender::RandomNumberGenerator rng(0);
- for (int i = 0; i < points_len; i++) {
- const int random_weight_total = rng.get_float() * weight_total;
-
- /* Find the triangle index based on the weights. TODO: Use binary search. */
- int i_tri = 0;
- for (; i_tri < looptris_len; i_tri++) {
- if (weights[i_tri] > random_weight_total) {
- break;
- }
+ Vector<float3> points;
+
+ for (const int looptri_index : IndexRange(looptris_len)) {
+ const MLoopTri &looptri = looptris[looptri_index];
+ const int v0_index = mesh->mloop[looptri.tri[0]].v;
+ const int v1_index = mesh->mloop[looptri.tri[1]].v;
+ const int v2_index = mesh->mloop[looptri.tri[2]].v;
+ const float3 v0_pos = mesh->mvert[v0_index].co;
+ const float3 v1_pos = mesh->mvert[v1_index].co;
+ const float3 v2_pos = mesh->mvert[v2_index].co;
+ const float v0_density_factor = vertex_density_factors[v0_index];
+ const float v1_density_factor = vertex_density_factors[v1_index];
+ const float v2_density_factor = vertex_density_factors[v2_index];
+ const float looptri_density_factor = (v0_density_factor + v1_density_factor +
+ v2_density_factor) /
+ 3.0f;
+ const float area = area_tri_v3(v0_pos, v1_pos, v2_pos);
+
+ const int looptri_seed = BLI_hash_int(looptri_index);
+ RandomNumberGenerator looptri_rng(looptri_seed);
+
+ const float points_amount_fl = area * density * looptri_density_factor;
+ const float add_point_probability = fractf(points_amount_fl);
+ const bool add_point = add_point_probability > looptri_rng.get_float();
+ const int point_amount = (int)points_amount_fl + (int)add_point;
+
+ for (int i = 0; i < point_amount; i++) {
+ const float3 bary_coords = looptri_rng.get_barycentric_coordinates();
+ float3 point_pos;
+ interp_v3_v3v3v3(point_pos, v0_pos, v1_pos, v2_pos, bary_coords);
+ points.append(point_pos);
}
- BLI_assert(i_tri < looptris_len);
-
- /* Place the point randomly in the selected triangle. */
- float *v0, *v1, *v2;
- mesh_loop_tri_corner_coords(mesh, i_tri, &v0, &v1, &v2);
-
- float3 co = rng.get_triangle_sample_3d(v0, v1, v2);
- pointcloud->co[i][0] = co.x;
- pointcloud->co[i][1] = co.y;
- pointcloud->co[i][2] = co.z;
- pointcloud->radius[i] = 0.05f; /* TODO: Use radius attribute / vertex vgroup. */
}
- return pointcloud;
+ return points;
}
-namespace blender::nodes {
static void geo_point_distribute_exec(bNode *UNUSED(node),
GeoNodeInputs inputs,
GeoNodeOutputs outputs)
@@ -134,19 +113,28 @@ static void geo_point_distribute_exec(bNode *UNUSED(node),
}
const float density = inputs.extract<float>("Density");
- const float minimum_radius = inputs.extract<float>("Minimum Radius");
+ const int density_attribute_index = std::max(-1, inputs.extract<int>("Density Attribute Index"));
if (density <= 0.0f) {
+ geometry_set->replace_mesh(nullptr);
+ geometry_set->replace_pointcloud(nullptr);
outputs.set("Geometry", std::move(geometry_set));
return;
}
const Mesh *mesh_in = geometry_set->get_mesh_for_read();
- PointCloud *pointcloud_out = scatter_pointcloud_from_mesh(mesh_in, density, minimum_radius);
+ Vector<float3> points = scatter_points_from_mesh(mesh_in, density, density_attribute_index);
+
+ PointCloud *pointcloud = BKE_pointcloud_new_nomain(points.size());
+ memcpy(pointcloud->co, points.data(), sizeof(float3) * points.size());
+ for (const int i : points.index_range()) {
+ *(float3 *)(pointcloud->co + i) = points[i];
+ pointcloud->radius[i] = 0.05f;
+ }
- /* For now, replace any existing pointcloud in the geometry. */
make_geometry_set_mutable(geometry_set);
- geometry_set->replace_pointcloud(pointcloud_out);
+ geometry_set->replace_mesh(nullptr);
+ geometry_set->replace_pointcloud(pointcloud);
outputs.set("Geometry", std::move(geometry_set));
}
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