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implemented occlusion estimation for objects with negative volumes

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This commit is contained in:
PavelMikus 2022-03-14 12:42:41 +01:00
parent ca259caf33
commit bb89b630d9
2 changed files with 99 additions and 38 deletions
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111
src/libslic3r/GCode/SeamPlacer.cpp
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@ -8,7 +8,6 @@
#include <algorithm>
#include <queue>
//For polynomial fitting
#include <Eigen/Dense>
#include <Eigen/QR>
@ -33,6 +32,10 @@ namespace Slic3r {
namespace SeamPlacerImpl {
template<typename T> int sgn(T val) {
return int(T(0) < val) - int(val < T(0));
}
// base function: ((e^(((1)/(x^(2)+1)))-1)/(e-1))
// checkout e.g. here: https://www.geogebra.org/calculator
float gauss(float value, float mean_x_coord, float mean_value, float falloff_speed) {
@ -178,7 +181,7 @@ Vec3f sample_power_cosine_hemisphere(const Vec2f &samples, float power) {
}
std::vector<FaceVisibilityInfo> raycast_visibility(const AABBTreeIndirect::Tree<3, float> &raycasting_tree,
const indexed_triangle_set &triangles) {
const indexed_triangle_set &triangles, size_t negative_volumes_start_index) {
BOOST_LOG_TRIVIAL(debug)
<< "SeamPlacer: raycast visibility for " << triangles.indices.size() << " triangles: start";
@ -194,6 +197,8 @@ std::vector<FaceVisibilityInfo> raycast_visibility(const AABBTreeIndirect::Tree<
}
}
bool model_contains_negative_parts = negative_volumes_start_index < triangles.indices.size();
std::vector<FaceVisibilityInfo> result(triangles.indices.size());
tbb::parallel_for(tbb::blocked_range<size_t>(0, result.size()),
[&](tbb::blocked_range<size_t> r) {
@ -214,17 +219,45 @@ std::vector<FaceVisibilityInfo> raycast_visibility(const AABBTreeIndirect::Tree<
for (const auto &dir : precomputed_sample_directions) {
Vec3f final_ray_dir = (f.to_world(dir));
if (!model_contains_negative_parts) {
igl::Hit hitpoint;
// FIXME: This AABBTTreeIndirect query will not compile for float ray origin and
// direction.
Vec3d ray_origin_d = (center + normal).cast<double>(); // start one mm above surface.
Vec3d final_ray_dir_d = final_ray_dir.cast<double>();
Vec3d ray_origin_d = (center + normal * 0.1).cast<double>(); // start above surface.
bool hit = AABBTreeIndirect::intersect_ray_first_hit(triangles.vertices,
triangles.indices, raycasting_tree, ray_origin_d, final_ray_dir_d, hitpoint);
if (hit) {
dest.visibility -= decrease;
}
} else {
std::vector<igl::Hit> hits;
int in_negative = 0;
if (face_index >= negative_volumes_start_index) { // if casting from negative volume face, invert direction
final_ray_dir = -1.0 * final_ray_dir;
normal = -normal;
}
Vec3d final_ray_dir_d = final_ray_dir.cast<double>();
Vec3d ray_origin_d = (center + normal * 0.1).cast<double>(); // start above surface.
bool some_hit = AABBTreeIndirect::intersect_ray_all_hits(triangles.vertices,
triangles.indices, raycasting_tree,
ray_origin_d, final_ray_dir_d, hits);
if (some_hit) {
// NOTE: iterating in reverse, from the last hit for one simple reason: We know the state of the ray at that point;
// It cannot be inside model, and it cannot be inside negative volume
for (int hit_index = hits.size() - 1; hit_index >= 0; --hit_index) {
if (hits[hit_index].id >= negative_volumes_start_index) { //negative volume hit
Vec3f normal = its_face_normal(triangles, hits[hit_index].id);
in_negative += sgn(normal.dot(final_ray_dir)); // if volume face aligns with ray dir, we are leaving negative space
// which in reverse hit analysis means, that we are entering negative space :) and vice versa
} else if (in_negative <= 0) { //object hit and we are not in negative space
dest.visibility -= decrease;
break;
}
}
}
}
}
}
});
@ -538,34 +571,58 @@ float calculate_overhang(const SeamCandidate &point, const SeamCandidate &under_
// stores enforces and blockers
void compute_global_occlusion(GlobalModelInfo &result, const PrintObject *po) {
BOOST_LOG_TRIVIAL(debug)
<< "SeamPlacer: build AABB tree for raycasting and gather occlusion info: start";
// Build AABB tree for raycasting
<< "SeamPlacer: gather occlusion meshes: start";
auto obj_transform = po->trafo_centered();
indexed_triangle_set triangle_set;
indexed_triangle_set negative_volumes_set;
//add all parts
for (const ModelVolume *model_volume : po->model_object()->volumes) {
if (model_volume->type() == ModelVolumeType::MODEL_PART) {
if (model_volume->type() == ModelVolumeType::MODEL_PART
|| model_volume->type() == ModelVolumeType::NEGATIVE_VOLUME) {
auto model_transformation = model_volume->get_matrix();
indexed_triangle_set model_its = model_volume->mesh().its;
its_transform(model_its, model_transformation);
if (model_volume->type() == ModelVolumeType::MODEL_PART) {
its_merge(triangle_set, model_its);
} else {
its_merge(negative_volumes_set, model_its);
}
}
}
BOOST_LOG_TRIVIAL(debug)
<< "SeamPlacer: gather occlusion meshes: end";
float target_error = SeamPlacer::raycasting_decimation_target_error;
its_quadric_edge_collapse(triangle_set, 0, &target_error, nullptr, nullptr);
BOOST_LOG_TRIVIAL(debug)
<< "SeamPlacer: simplify occlusion meshes: start";
//simplify raycasting mesh
its_quadric_edge_collapse(triangle_set, SeamPlacer::raycasting_decimation_target_triangle_count, nullptr, nullptr,
nullptr);
triangle_set = its_subdivide(triangle_set, SeamPlacer::raycasting_subdivision_target_length);
//simplify negative volumes
its_quadric_edge_collapse(negative_volumes_set, SeamPlacer::raycasting_decimation_target_triangle_count, nullptr,
nullptr,
nullptr);
negative_volumes_set = its_subdivide(negative_volumes_set, SeamPlacer::raycasting_subdivision_target_length);
size_t negative_volumes_start_index = triangle_set.indices.size();
its_merge(triangle_set, negative_volumes_set);
its_transform(triangle_set, obj_transform);
BOOST_LOG_TRIVIAL(debug)
<< "SeamPlacer: simplify occlusion meshes: end";
BOOST_LOG_TRIVIAL(debug)
<< "SeamPlacer:build AABB tree: start";
auto raycasting_tree = AABBTreeIndirect::build_aabb_tree_over_indexed_triangle_set(triangle_set.vertices,
triangle_set.indices);
BOOST_LOG_TRIVIAL(debug)
<< "SeamPlacer:build AABB tree: end";
result.model = triangle_set;
result.model_tree = raycasting_tree;
result.visiblity_info = raycast_visibility(raycasting_tree, triangle_set);
BOOST_LOG_TRIVIAL(debug)
<< "SeamPlacer: build AABB tree for raycasting and gather occlusion info: end";
result.visiblity_info = raycast_visibility(raycasting_tree, triangle_set, negative_volumes_start_index);
#ifdef DEBUG_FILES
auto filename = debug_out_path(("visiblity_of_" + std::to_string(po->id().id) + ".obj").c_str());
@ -615,7 +672,7 @@ struct SeamComparator {
float compute_angle_penalty(float ccw_angle) const {
// This function is used:
// ((ℯ^(((1)/(x^(2)*3+1)))-1)/(ℯ-1))*1+((1)/(2+ℯ^(-x)))
// looks terribly, but it is gaussian combined with sigmoid,
// looks scary, but it is gaussian combined with sigmoid,
// so that concave points have much smaller penalty over convex ones
return gauss(ccw_angle, 0.0f, 1.0f, 3.0f) +
@ -651,9 +708,11 @@ struct SeamComparator {
}
//ranges: [0 - 1] (0 - 1.3] [0.1 - 1.1)
float penalty_a = (a.visibility + SeamPlacer::additional_angle_importance) * compute_angle_penalty(a.local_ccw_angle)
float penalty_a = (a.visibility + SeamPlacer::additional_angle_importance)
* compute_angle_penalty(a.local_ccw_angle)
* distance_penalty_a;
float penalty_b = (b.visibility + SeamPlacer::additional_angle_importance) * compute_angle_penalty(b.local_ccw_angle)
float penalty_b = (b.visibility + SeamPlacer::additional_angle_importance)
* compute_angle_penalty(b.local_ccw_angle)
* distance_penalty_b;
return penalty_a < penalty_b;
@ -692,8 +751,10 @@ struct SeamComparator {
}
//ranges: [0 - 1] (0 - 1.3] ;
float penalty_a = (a.visibility + SeamPlacer::additional_angle_importance) * compute_angle_penalty(a.local_ccw_angle);
float penalty_b = (b.visibility + SeamPlacer::additional_angle_importance) * compute_angle_penalty(b.local_ccw_angle);
float penalty_a = (a.visibility + SeamPlacer::additional_angle_importance)
* compute_angle_penalty(a.local_ccw_angle);
float penalty_b = (b.visibility + SeamPlacer::additional_angle_importance)
* compute_angle_penalty(b.local_ccw_angle);
return penalty_a <= penalty_b || std::abs(penalty_a - penalty_b) < SeamPlacer::seam_align_score_tolerance;
}
@ -714,7 +775,7 @@ void debug_export_points(const std::vector<std::vector<SeamPlacerImpl::SeamCandi
const BoundingBox &bounding_box, std::string object_name, const SeamComparator &comparator) {
for (size_t layer_idx = 0; layer_idx < object_perimter_points.size(); ++layer_idx) {
std::string angles_file_name = debug_out_path((object_name + "_angles_" + std::to_string(layer_idx) + ".svg").c_str());
SVG angles_svg { angles_file_name, bounding_box };
SVG angles_svg {angles_file_name, bounding_box};
float min_vis = 0;
float max_vis = min_vis;
@ -735,16 +796,16 @@ void debug_export_points(const std::vector<std::vector<SeamPlacerImpl::SeamCandi
}
std::string visiblity_file_name = debug_out_path((object_name + "_visibility_" + std::to_string(layer_idx) + ".svg").c_str());
SVG visibility_svg { visiblity_file_name, bounding_box };
SVG visibility_svg {visiblity_file_name, bounding_box};
std::string weights_file_name = debug_out_path((object_name + "_weight_" + std::to_string(layer_idx) + ".svg").c_str());
SVG weight_svg {weights_file_name, bounding_box };
SVG weight_svg {weights_file_name, bounding_box};
for (const SeamCandidate &point : object_perimter_points[layer_idx]) {
Vec3i color = value_rgbi(min_vis, max_vis, point.visibility);
std::string visibility_fill = "rgb(" + std::to_string(color.x()) + "," + std::to_string(color.y()) + ","
+ std::to_string(color.z()) + ")";
visibility_svg.draw(scaled(Vec2f(point.position.head<2>())), visibility_fill);
Vec3i weight_color = value_rgbi(min_weight, max_weight, comparator.get_penalty(point));
Vec3i weight_color = value_rgbi(min_weight, max_weight, -comparator.get_penalty(point));
std::string weight_fill = "rgb(" + std::to_string(weight_color.x()) + "," + std::to_string(weight_color.y())
+ ","
+ std::to_string(weight_color.z()) + ")";
@ -789,7 +850,7 @@ void pick_random_seam_point(std::vector<SeamCandidate> &perimeter_points, size_t
// algorithm keeps a list of viable points and their lengths. If it finds a point
// that is much better than the viable_example_index (e.g. better type, no overhang; see is_first_not_much_worse)
// then it throws away stored lists and starts from start
// in the end, he list should contain points with same type (Enforced > Neutral > Blocked) and also only those which are not
// in the end, the list should contain points with same type (Enforced > Neutral > Blocked) and also only those which are not
// big overhang.
size_t viable_example_index = start_index;
size_t end_index = perimeter_points[start_index].perimeter->end_index;
@ -973,7 +1034,7 @@ bool SeamPlacer::find_next_seam_in_layer(const PrintObject *po,
if ((closest_point.position - projected_position).norm() < SeamPlacer::seam_align_tolerable_dist
&& comparator.is_first_not_much_worse(closest_point, next_layer_seam)
&& are_similar(last_point, closest_point)) {
seam_string.push_back({ layer_idx, closest_point_index });
seam_string.push_back( { layer_idx, closest_point_index });
last_point_indexes = std::pair<size_t, size_t> { layer_idx, closest_point_index };
return true;
} else {
@ -1063,7 +1124,7 @@ void SeamPlacer::align_seam_points(const PrintObject *po, const SeamPlacerImpl::
skips = SeamPlacer::seam_align_tolerable_skips / 2;
last_point_indexes = std::pair<size_t, size_t>(layer_idx, seam_index);
while (skips >= 0 && next_layer >= 0) {
if (find_next_seam_in_layer(po, last_point_indexes, next_layer, comparator,seam_string)) {
if (find_next_seam_in_layer(po, last_point_indexes, next_layer, comparator, seam_string)) {
//String added, last_point_pos updated, nothing to be done
} else {
// Layer skipped, reduce number of available skips

2
src/libslic3r/GCode/SeamPlacer.hpp
View File

@ -86,7 +86,7 @@ class SeamPlacer {
public:
using SeamCandidatesTree =
KDTreeIndirect<3, float, SeamPlacerImpl::SeamCandidateCoordinateFunctor>;
static constexpr float raycasting_decimation_target_error = 1.0f;
static constexpr size_t raycasting_decimation_target_triangle_count = 10000;
static constexpr float raycasting_subdivision_target_length = 2.0f;
//square of number of rays per triangle
static constexpr size_t sqr_rays_per_triangle = 7;