diff options
| -rw-r--r-- | source/blender/blenlib/BLI_kdopbvh.h | 1 | ||||
| -rw-r--r-- | source/blender/blenlib/intern/BLI_kdopbvh.c | 19 | ||||
| -rw-r--r-- | source/blender/editors/space_node/drawnode.c | 10 | ||||
| -rw-r--r-- | source/blender/makesdna/DNA_node_types.h | 5 | ||||
| -rw-r--r-- | source/blender/makesrna/intern/rna_nodetree.c | 26 | ||||
| -rw-r--r-- | source/blender/nodes/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | source/blender/nodes/NOD_static_types.h | 2 | ||||
| -rw-r--r-- | source/blender/nodes/geometry/node_geometry_util.hh | 8 | ||||
| -rw-r--r-- | source/blender/nodes/geometry/nodes/node_geo_point_distribute.cc | 178 | ||||
| -rw-r--r-- | source/blender/nodes/geometry/nodes/node_geo_point_distribute_poisson_disk.cc | 280 |
10 files changed, 521 insertions, 9 deletions
diff --git a/source/blender/blenlib/BLI_kdopbvh.h b/source/blender/blenlib/BLI_kdopbvh.h index c34b71a60f9..5e0ea4f2a99 100644 --- a/source/blender/blenlib/BLI_kdopbvh.h +++ b/source/blender/blenlib/BLI_kdopbvh.h @@ -178,6 +178,7 @@ int *BLI_bvhtree_intersect_plane(BVHTree *tree, float plane[4], uint *r_intersec int BLI_bvhtree_get_len(const BVHTree *tree); int BLI_bvhtree_get_tree_type(const BVHTree *tree); float BLI_bvhtree_get_epsilon(const BVHTree *tree); +void BLI_bvhtree_get_bounding_box(BVHTree *tree, float r_bb_min[3], float r_bb_max[3]); /* find nearest node to the given coordinates * (if nearest is given it will only search nodes where diff --git a/source/blender/blenlib/intern/BLI_kdopbvh.c b/source/blender/blenlib/intern/BLI_kdopbvh.c index f126c5a977b..0f90ad3a490 100644 --- a/source/blender/blenlib/intern/BLI_kdopbvh.c +++ b/source/blender/blenlib/intern/BLI_kdopbvh.c @@ -1076,6 +1076,25 @@ float BLI_bvhtree_get_epsilon(const BVHTree *tree) return tree->epsilon; } +/** + * This function returns the bounding box of the BVH tree. + */ +void BLI_bvhtree_get_bounding_box(BVHTree *tree, float r_bb_min[3], float r_bb_max[3]) +{ + BVHNode *root = tree->nodes[tree->totleaf]; + if (root != NULL) { + const float bb_min[3] = {root->bv[0], root->bv[2], root->bv[4]}; + const float bb_max[3] = {root->bv[1], root->bv[3], root->bv[5]}; + copy_v3_v3(r_bb_min, bb_min); + copy_v3_v3(r_bb_max, bb_max); + } + else { + BLI_assert(false); + zero_v3(r_bb_min); + zero_v3(r_bb_max); + } +} + /** \} */ /* -------------------------------------------------------------------- */ diff --git a/source/blender/editors/space_node/drawnode.c b/source/blender/editors/space_node/drawnode.c index 421d645d7bd..2857c08cad6 100644 --- a/source/blender/editors/space_node/drawnode.c +++ b/source/blender/editors/space_node/drawnode.c @@ -3208,6 +3208,13 @@ static void node_geometry_buts_attribute_mix(uiLayout *layout, uiItemR(col, ptr, "input_type_b", DEFAULT_FLAGS, IFACE_("B"), ICON_NONE); } +static void node_geometry_buts_attribute_point_distribute(uiLayout *layout, + bContext *UNUSED(C), + PointerRNA *ptr) +{ + uiItemR(layout, ptr, "distribute_method", DEFAULT_FLAGS, "", ICON_NONE); +} + static void node_geometry_set_butfunc(bNodeType *ntype) { switch (ntype->type) { @@ -3235,6 +3242,9 @@ static void node_geometry_set_butfunc(bNodeType *ntype) case GEO_NODE_ATTRIBUTE_MIX: ntype->draw_buttons = node_geometry_buts_attribute_mix; break; + case GEO_NODE_POINT_DISTRIBUTE: + ntype->draw_buttons = node_geometry_buts_attribute_point_distribute; + break; } } diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h index 9cf64743843..34a5372892c 100644 --- a/source/blender/makesdna/DNA_node_types.h +++ b/source/blender/makesdna/DNA_node_types.h @@ -1501,6 +1501,11 @@ typedef enum GeometryNodeAttributeInputMode { GEO_NODE_ATTRIBUTE_INPUT_COLOR = 3, } GeometryNodeAttributeInputMode; +typedef enum GeometryNodePointDistributeMethod { + GEO_NODE_POINT_DISTRIBUTE_RANDOM = 0, + GEO_NODE_POINT_DISTRIBUTE_POISSON = 1, +} GeometryNodePointDistributeMethod; + #ifdef __cplusplus } #endif diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c index 34f4d287d6e..1731a42583b 100644 --- a/source/blender/makesrna/intern/rna_nodetree.c +++ b/source/blender/makesrna/intern/rna_nodetree.c @@ -452,6 +452,20 @@ static const EnumPropertyItem rna_node_geometry_attribute_input_type_items[] = { {0, NULL, 0, NULL, NULL}, }; +static const EnumPropertyItem rna_node_geometry_point_distribute_method_items[] = { + {GEO_NODE_POINT_DISTRIBUTE_RANDOM, + "RANDOM", + 0, + "Random", + "Distribute points randomly on the surface"}, + {GEO_NODE_POINT_DISTRIBUTE_POISSON, + "POISSON", + 0, + "Poisson Disk", + "Project points on the surface evenly with a Poisson disk distribution"}, + {0, NULL, 0, NULL, NULL}, +}; + #endif #ifdef RNA_RUNTIME @@ -8481,6 +8495,18 @@ static void def_geo_attribute_mix(StructRNA *srna) RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_socket_update"); } +static void def_geo_point_distribute(StructRNA *srna) +{ + PropertyRNA *prop; + + prop = RNA_def_property(srna, "distribute_method", PROP_ENUM, PROP_NONE); + RNA_def_property_enum_sdna(prop, NULL, "custom1"); + RNA_def_property_enum_items(prop, rna_node_geometry_point_distribute_method_items); + RNA_def_property_enum_default(prop, GEO_NODE_POINT_DISTRIBUTE_RANDOM); + RNA_def_property_ui_text(prop, "Distribution Method", "Method to use for scattering points"); + RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_socket_update"); +} + /* -------------------------------------------------------------------------- */ static void rna_def_shader_node(BlenderRNA *brna) diff --git a/source/blender/nodes/CMakeLists.txt b/source/blender/nodes/CMakeLists.txt index 779680a5da7..46536903d55 100644 --- a/source/blender/nodes/CMakeLists.txt +++ b/source/blender/nodes/CMakeLists.txt @@ -148,6 +148,7 @@ set(SRC geometry/nodes/node_geo_attribute_mix.cc geometry/nodes/node_geo_object_info.cc geometry/nodes/node_geo_point_distribute.cc + geometry/nodes/node_geo_point_distribute_poisson_disk.cc geometry/nodes/node_geo_point_instance.cc geometry/nodes/node_geo_subdivision_surface.cc geometry/nodes/node_geo_transform.cc diff --git a/source/blender/nodes/NOD_static_types.h b/source/blender/nodes/NOD_static_types.h index 681286ae5ab..68efb0806fd 100644 --- a/source/blender/nodes/NOD_static_types.h +++ b/source/blender/nodes/NOD_static_types.h @@ -271,7 +271,7 @@ DefNode(GeometryNode, GEO_NODE_EDGE_SPLIT, 0, "EDGE_SPLIT", EdgeSplit, "Edge Spl DefNode(GeometryNode, GEO_NODE_TRANSFORM, 0, "TRANSFORM", Transform, "Transform", "") DefNode(GeometryNode, GEO_NODE_SUBDIVISION_SURFACE, 0, "SUBDIVISION_SURFACE", SubdivisionSurface, "Subdivision Surface", "") DefNode(GeometryNode, GEO_NODE_BOOLEAN, def_geo_boolean, "BOOLEAN", Boolean, "Boolean", "") -DefNode(GeometryNode, GEO_NODE_POINT_DISTRIBUTE, 0, "POINT_DISTRIBUTE", PointDistribute, "Point Distribute", "") +DefNode(GeometryNode, GEO_NODE_POINT_DISTRIBUTE, def_geo_point_distribute, "POINT_DISTRIBUTE", PointDistribute, "Point Distribute", "") DefNode(GeometryNode, GEO_NODE_POINT_INSTANCE, def_geo_point_instance, "POINT_INSTANCE", PointInstance, "Point Instance", "") DefNode(GeometryNode, GEO_NODE_OBJECT_INFO, 0, "OBJECT_INFO", ObjectInfo, "Object Info", "") DefNode(GeometryNode, GEO_NODE_ATTRIBUTE_RANDOMIZE, def_geo_attribute_randomize, "ATTRIBUTE_RANDOMIZE", AttributeRandomize, "Attribute Randomize", "") diff --git a/source/blender/nodes/geometry/node_geometry_util.hh b/source/blender/nodes/geometry/node_geometry_util.hh index ec389961615..c97463cdc22 100644 --- a/source/blender/nodes/geometry/node_geometry_util.hh +++ b/source/blender/nodes/geometry/node_geometry_util.hh @@ -42,4 +42,10 @@ namespace blender::nodes { void update_attribute_input_socket_availabilities(bNode &node, const StringRef name, const GeometryNodeAttributeInputMode mode); -} + +void poisson_disk_point_elimination(Vector<float3> const *input_points, + Vector<float3> *output_points, + float maximum_distance, + float3 boundbox); + +} // namespace blender::nodes 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 2f5f7e264bc..8be9636e14d 100644 --- a/source/blender/nodes/geometry/nodes/node_geo_point_distribute.cc +++ b/source/blender/nodes/geometry/nodes/node_geo_point_distribute.cc @@ -24,6 +24,7 @@ #include "DNA_meshdata_types.h" #include "DNA_pointcloud_types.h" +#include "BKE_bvhutils.h" #include "BKE_deform.h" #include "BKE_mesh.h" #include "BKE_mesh_runtime.h" @@ -33,8 +34,10 @@ 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 Distance"), 0.1f, 0.0f, 0.0f, 0.0f, 0.0f, 100000.0f, PROP_NONE}, + {SOCK_FLOAT, N_("Maximum Density"), 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 100000.0f, PROP_NONE}, {SOCK_STRING, N_("Density Attribute")}, + {SOCK_INT, N_("Seed"), 0, 0, 0, 0, -10000, 10000}, {-1, ""}, }; @@ -43,11 +46,19 @@ static bNodeSocketTemplate geo_node_point_distribute_out[] = { {-1, ""}, }; +static void node_point_distribute_update(bNodeTree *UNUSED(ntree), bNode *node) +{ + bNodeSocket *sock_min_dist = (bNodeSocket *)BLI_findlink(&node->inputs, 1); + + nodeSetSocketAvailability(sock_min_dist, ELEM(node->custom1, GEO_NODE_POINT_DISTRIBUTE_POISSON)); +} + namespace blender::nodes { -static Vector<float3> scatter_points_from_mesh(const Mesh *mesh, - const float density, - const FloatReadAttribute &density_factors) +static Vector<float3> random_scatter_points_from_mesh(const Mesh *mesh, + const float density, + const FloatReadAttribute &density_factors, + const int seed) { /* This only updates a cache and can be considered to be logically const. */ const MLoopTri *looptris = BKE_mesh_runtime_looptri_ensure(const_cast<Mesh *>(mesh)); @@ -71,7 +82,7 @@ static Vector<float3> scatter_points_from_mesh(const Mesh *mesh, 3.0f; const float area = area_tri_v3(v0_pos, v1_pos, v2_pos); - const int looptri_seed = BLI_hash_int(looptri_index); + const int looptri_seed = BLI_hash_int(looptri_index + seed); RandomNumberGenerator looptri_rng(looptri_seed); const float points_amount_fl = area * density * looptri_density_factor; @@ -90,17 +101,158 @@ static Vector<float3> scatter_points_from_mesh(const Mesh *mesh, return points; } +struct RayCastAll_Data { + void *bvhdata; + + BVHTree_RayCastCallback raycast_callback; + + const Mesh *mesh; + float base_weight; + FloatReadAttribute *density_factors; + Vector<float3> *projected_points; + float cur_point_weight; +}; + +static void project_2d_bvh_callback(void *userdata, + int index, + const BVHTreeRay *ray, + BVHTreeRayHit *hit) +{ + struct RayCastAll_Data *data = (RayCastAll_Data *)userdata; + data->raycast_callback(data->bvhdata, index, ray, hit); + if (hit->index != -1) { + /* This only updates a cache and can be considered to be logically const. */ + const MLoopTri *looptris = BKE_mesh_runtime_looptri_ensure(const_cast<Mesh *>(data->mesh)); + const MVert *mvert = data->mesh->mvert; + + const MLoopTri &looptri = looptris[index]; + const FloatReadAttribute &density_factors = data->density_factors[0]; + + const int v0_index = data->mesh->mloop[looptri.tri[0]].v; + const int v1_index = data->mesh->mloop[looptri.tri[1]].v; + const int v2_index = data->mesh->mloop[looptri.tri[2]].v; + + const float v0_density_factor = std::max(0.0f, density_factors[v0_index]); + const float v1_density_factor = std::max(0.0f, density_factors[v1_index]); + const float v2_density_factor = std::max(0.0f, density_factors[v2_index]); + + /* Calculate barycentric weights for hit point. */ + float3 weights; + interp_weights_tri_v3( + weights, mvert[v0_index].co, mvert[v1_index].co, mvert[v2_index].co, hit->co); + + float point_weight = weights[0] * v0_density_factor + weights[1] * v1_density_factor + + weights[2] * v2_density_factor; + + point_weight *= data->base_weight; + + if (point_weight >= FLT_EPSILON && data->cur_point_weight <= point_weight) { + data->projected_points->append(hit->co); + } + } +} + +static Vector<float3> poisson_scatter_points_from_mesh(const Mesh *mesh, + const float density, + const float minimum_distance, + const FloatReadAttribute &density_factors, + const int seed) +{ + Vector<float3> points; + + if (minimum_distance <= FLT_EPSILON || density <= FLT_EPSILON) { + return points; + } + + /* Scatter points randomly on the mesh with higher density (5-7) times higher than desired for + * good quality possion disk distributions. */ + int quality = 5; + const int output_points_target = 1000; + points.resize(output_points_target * quality); + + const float required_area = output_points_target * + (2.0f * sqrtf(3.0f) * minimum_distance * minimum_distance); + const float point_scale_multiplier = sqrtf(required_area); + + { + const int rnd_seed = BLI_hash_int(seed); + RandomNumberGenerator point_rng(rnd_seed); + + for (int i = 0; i < points.size(); i++) { + points[i].x = point_rng.get_float() * point_scale_multiplier; + points[i].y = point_rng.get_float() * point_scale_multiplier; + points[i].z = 0.0f; + } + } + + /* Eliminate the scattered points until we get a possion distribution. */ + Vector<float3> output_points(output_points_target); + + const float3 bounds_max = float3(point_scale_multiplier, point_scale_multiplier, 0); + poisson_disk_point_elimination(&points, &output_points, 2.0f * minimum_distance, bounds_max); + Vector<float3> final_points; + final_points.reserve(output_points_target); + + /* Check if we have any points we should remove from the final possion distribition. */ + BVHTreeFromMesh treedata; + BKE_bvhtree_from_mesh_get(&treedata, const_cast<Mesh *>(mesh), BVHTREE_FROM_LOOPTRI, 2); + + float3 bb_min, bb_max; + BLI_bvhtree_get_bounding_box(treedata.tree, bb_min, bb_max); + + struct RayCastAll_Data data; + data.bvhdata = &treedata; + data.raycast_callback = treedata.raycast_callback; + data.mesh = mesh; + data.projected_points = &final_points; + data.density_factors = const_cast<FloatReadAttribute *>(&density_factors); + data.base_weight = std::min( + 1.0f, density / (output_points.size() / (point_scale_multiplier * point_scale_multiplier))); + + const float max_dist = bb_max[2] - bb_min[2] + 2.0f; + const float3 dir = float3(0, 0, -1); + float3 raystart; + raystart.z = bb_max[2] + 1.0f; + + float tile_start_x_coord = bb_min[0]; + int tile_repeat_x = ceilf((bb_max[0] - bb_min[0]) / point_scale_multiplier); + + float tile_start_y_coord = bb_min[1]; + int tile_repeat_y = ceilf((bb_max[1] - bb_min[1]) / point_scale_multiplier); + + for (int x = 0; x < tile_repeat_x; x++) { + float tile_curr_x_coord = x * point_scale_multiplier + tile_start_x_coord; + for (int y = 0; y < tile_repeat_y; y++) { + float tile_curr_y_coord = y * point_scale_multiplier + tile_start_y_coord; + for (int idx = 0; idx < output_points.size(); idx++) { + raystart.x = output_points[idx].x + tile_curr_x_coord; + raystart.y = output_points[idx].y + tile_curr_y_coord; + + data.cur_point_weight = (float)idx / (float)output_points.size(); + + BLI_bvhtree_ray_cast_all( + treedata.tree, raystart, dir, 0.0f, max_dist, project_2d_bvh_callback, &data); + } + } + } + + return final_points; +} + static void geo_node_point_distribute_exec(GeoNodeExecParams params) { GeometrySet geometry_set = params.extract_input<GeometrySet>("Geometry"); GeometrySet geometry_set_out; + GeometryNodePointDistributeMethod distribute_method = + static_cast<GeometryNodePointDistributeMethod>(params.node().custom1); + if (!geometry_set.has_mesh()) { params.set_output("Geometry", std::move(geometry_set_out)); return; } - const float density = params.extract_input<float>("Density"); + const float density = params.extract_input<float>("Maximum Density"); const std::string density_attribute = params.extract_input<std::string>("Density Attribute"); if (density <= 0.0f) { @@ -113,8 +265,19 @@ static void geo_node_point_distribute_exec(GeoNodeExecParams params) const FloatReadAttribute density_factors = mesh_component.attribute_get_for_read<float>( density_attribute, ATTR_DOMAIN_POINT, 1.0f); + const int seed = params.get_input<int>("Seed"); - Vector<float3> points = scatter_points_from_mesh(mesh_in, density, density_factors); + Vector<float3> points; + + switch (distribute_method) { + case GEO_NODE_POINT_DISTRIBUTE_RANDOM: + points = random_scatter_points_from_mesh(mesh_in, density, density_factors, seed); + break; + case GEO_NODE_POINT_DISTRIBUTE_POISSON: + const float min_dist = params.extract_input<float>("Minimum Distance"); + points = poisson_scatter_points_from_mesh(mesh_in, density, min_dist, density_factors, seed); + break; + } PointCloud *pointcloud = BKE_pointcloud_new_nomain(points.size()); memcpy(pointcloud->co, points.data(), sizeof(float3) * points.size()); @@ -135,6 +298,7 @@ void register_node_type_geo_point_distribute() geo_node_type_base( &ntype, GEO_NODE_POINT_DISTRIBUTE, "Point Distribute", NODE_CLASS_GEOMETRY, 0); node_type_socket_templates(&ntype, geo_node_point_distribute_in, geo_node_point_distribute_out); + node_type_update(&ntype, node_point_distribute_update); ntype.geometry_node_execute = blender::nodes::geo_node_point_distribute_exec; nodeRegisterType(&ntype); } diff --git a/source/blender/nodes/geometry/nodes/node_geo_point_distribute_poisson_disk.cc b/source/blender/nodes/geometry/nodes/node_geo_point_distribute_poisson_disk.cc new file mode 100644 index 00000000000..5dfdfce0e68 --- /dev/null +++ b/source/blender/nodes/geometry/nodes/node_geo_point_distribute_poisson_disk.cc @@ -0,0 +1,280 @@ +/* + * 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. + */ + +/* + * Based on Cem Yuksel. 2015. Sample Elimination for Generating Poisson Disk Sample + * ! Sets. Computer Graphics Forum 34, 2 (May 2015), 25-32. + * ! http://www.cemyuksel.com/research/sampleelimination/ + * Copyright (c) 2016, Cem Yuksel <cem@cemyuksel.com> + * All rights reserved. + */ + +#include "BLI_inplace_priority_queue.hh" +#include "BLI_kdtree.h" + +#include "node_geometry_util.hh" + +#include <iostream> + +namespace blender::nodes { + +static void tile_point(Vector<float3> *tiled_points, + Vector<size_t> *indices, + const float maximum_distance, + const float3 boundbox, + float3 const &point, + size_t index, + int dimension = 0) +{ + for (int dimension_iter = dimension; dimension_iter < 3; dimension_iter++) { + if (boundbox[dimension_iter] - point[dimension_iter] < maximum_distance) { + float3 point_tiled = point; + point_tiled[dimension_iter] -= boundbox[dimension_iter]; + + tiled_points->append(point_tiled); + indices->append(index); + + tile_point(tiled_points, + indices, + maximum_distance, + boundbox, + point_tiled, + index, + dimension_iter + 1); + } + + if (point[dimension_iter] < maximum_distance) { + float3 point_tiled = point; + point_tiled[dimension_iter] += boundbox[dimension_iter]; + + tiled_points->append(point_tiled); + indices->append(index); + + tile_point(tiled_points, + indices, + maximum_distance, + boundbox, + point_tiled, + index, + dimension_iter + 1); + } + } +} + +/** + * Returns the weight the point gets based on the distance to another point. + */ +static float point_weight_influence_get(const float maximum_distance, + const float minimum_distance, + float distance) +{ + const float alpha = 8.0f; + + if (distance < minimum_distance) { + distance = minimum_distance; + } + + return std::pow(1.0f - distance / maximum_distance, alpha); +} + +/** + * Weight each point based on their proximity to its neighbors + * + * For each index in the weight array add a weight based on the proximity the + * corresponding point has with its neighboors. + **/ +static void points_distance_weight_calculate(Vector<float> *weights, + const size_t point_id, + const float3 *input_points, + const void *kd_tree, + const float minimum_distance, + const float maximum_distance, + InplacePriorityQueue<float> *heap) +{ + KDTreeNearest_3d *nearest_point = nullptr; + int neighbors = BLI_kdtree_3d_range_search( + (KDTree_3d *)kd_tree, input_points[point_id], &nearest_point, maximum_distance); + + for (int i = 0; i < neighbors; i++) { + size_t neighbor_point_id = nearest_point[i].index; + + if (neighbor_point_id >= weights->size()) { + continue; + } + + /* The point should not influence itself. */ + if (neighbor_point_id == point_id) { + continue; + } + + const float weight_influence = point_weight_influence_get( + maximum_distance, minimum_distance, nearest_point[i].dist); + + /* In the first pass we just the weights. */ + if (heap == nullptr) { + (*weights)[point_id] += weight_influence; + } + /* When we run again we need to update the weights and the heap. */ + else { + (*weights)[neighbor_point_id] -= weight_influence; + heap->priority_decreased(neighbor_point_id); + } + } + + if (nearest_point) { + MEM_freeN(nearest_point); + } +} + +/** + * Returns the minimum radius fraction used by the default weight function. + */ +static float weight_limit_fraction_get(const size_t input_size, const size_t output_size) +{ + const float beta = 0.65f; + const float gamma = 1.5f; + float ratio = float(output_size) / float(input_size); + return (1.0f - std::pow(ratio, gamma)) * beta; +} + +/** + * Tile the input points. + */ +static void points_tiling(const float3 *input_points, + const size_t input_size, + void **kd_tree, + const float maximum_distance, + const float3 boundbox) + +{ + Vector<float3> tiled_points(input_points, input_points + input_size); + Vector<size_t> indices(input_size); + + for (size_t i = 0; i < input_size; i++) { + indices[i] = i; + } + + /* Tile the tree based on the boundbox. */ + for (size_t i = 0; i < input_size; i++) { + tile_point(&tiled_points, &indices, maximum_distance, boundbox, input_points[i], i); + } + + /* Build a new tree with the new indices and tiled points. */ + *kd_tree = BLI_kdtree_3d_new(tiled_points.size()); + for (size_t i = 0; i < tiled_points.size(); i++) { + BLI_kdtree_3d_insert(*(KDTree_3d **)kd_tree, indices[i], tiled_points[i]); + } + BLI_kdtree_3d_balance(*(KDTree_3d **)kd_tree); +} + +static void weighted_sample_elimination(const float3 *input_points, + const size_t input_size, + float3 *output_points, + const size_t output_size, + const float maximum_distance, + const float3 boundbox, + const bool do_copy_eliminated) +{ + const float minimum_distance = maximum_distance * + weight_limit_fraction_get(input_size, output_size); + + void *kd_tree = nullptr; + points_tiling(input_points, input_size, &kd_tree, maximum_distance, boundbox); + + /* Assign weights to each sample. */ + Vector<float> weights(input_size, 0.0f); + for (size_t point_id = 0; point_id < weights.size(); point_id++) { + points_distance_weight_calculate( + &weights, point_id, input_points, kd_tree, minimum_distance, maximum_distance, nullptr); + } + + /* Remove the points based on their weight. */ + InplacePriorityQueue<float> heap(weights); + + size_t sample_size = input_size; + while (sample_size > output_size) { + /* For each sample around it, remove its weight contribution and update the heap. */ + size_t point_id = heap.pop_index(); + points_distance_weight_calculate( + &weights, point_id, input_points, kd_tree, minimum_distance, maximum_distance, &heap); + sample_size--; + } + + /* Copy the samples to the output array. */ + size_t target_size = do_copy_eliminated ? input_size : output_size; + for (size_t i = 0; i < target_size; i++) { + size_t index = heap.all_indices()[i]; + output_points[i] = input_points[index]; + } + + /* Cleanup. */ + BLI_kdtree_3d_free((KDTree_3d *)kd_tree); +} + +static void progressive_sampling_reorder(Vector<float3> *output_points, + float maximum_density, + float3 boundbox) +{ + /* Re-order the points for progressive sampling. */ + Vector<float3> temporary_points(output_points->size()); + float3 *source_points = output_points->data(); + float3 *dest_points = temporary_points.data(); + size_t source_size = output_points->size(); + size_t dest_size = 0; + + while (source_size >= 3) { + dest_size = source_size * 0.5f; + + /* Changes the weight function radius using half of the number of samples. + * It is used for progressive sampling. */ + maximum_density *= std::sqrt(2.0f); + weighted_sample_elimination( + source_points, source_size, dest_points, dest_size, maximum_density, boundbox, true); + + if (dest_points != output_points->data()) { + mempcpy((*output_points)[dest_size], + dest_points[dest_size], + (source_size - dest_size) * sizeof(float3)); + } + + /* Swap the arrays around. */ + float3 *points_iter = source_points; + source_points = dest_points; + dest_points = points_iter; + source_size = dest_size; + } + if (source_points != output_points->data()) { + memcpy(output_points->data(), source_points, dest_size * sizeof(float3)); + } +} + +void poisson_disk_point_elimination(Vector<float3> const *input_points, + Vector<float3> *output_points, + float maximum_density, + float3 boundbox) +{ + weighted_sample_elimination(input_points->data(), + input_points->size(), + output_points->data(), + output_points->size(), + maximum_density, + boundbox, + false); + + progressive_sampling_reorder(output_points, maximum_density, boundbox); +} + +} // namespace blender::nodes |