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#include <iostream>
#include <fstream>
#include <random>
#include <catch2/catch_test_macros.hpp>
#include "libslic3r/TriangleMesh.hpp"
using namespace Slic3r;
TEST_CASE("Split empty mesh", "[its_split][its]") {
using namespace Slic3r;
indexed_triangle_set its;
std::vector<indexed_triangle_set> res = its_split(its);
REQUIRE(res.empty());
}
TEST_CASE("Split simple mesh consisting of one part", "[its_split][its]") {
using namespace Slic3r;
auto cube = its_make_cube(10., 10., 10.);
std::vector<indexed_triangle_set> res = its_split(cube);
REQUIRE(res.size() == 1);
REQUIRE(res.front().indices.size() == cube.indices.size());
REQUIRE(res.front().vertices.size() == cube.vertices.size());
}
void debug_write_obj(const std::vector<indexed_triangle_set> &res, const std::string &name)
{
#ifndef NDEBUG
size_t part_idx = 0;
for (auto &part_its : res) {
its_write_obj(part_its, (name + std::to_string(part_idx++) + ".obj").c_str());
}
#endif
}
TEST_CASE("Split two non-watertight mesh", "[its_split][its]") {
using namespace Slic3r;
auto cube1 = its_make_cube(10., 10., 10.);
cube1.indices.pop_back();
auto cube2 = cube1;
its_transform(cube1, identity3f().translate(Vec3f{-5.f, 0.f, 0.f}));
its_transform(cube2, identity3f().translate(Vec3f{5.f, 0.f, 0.f}));
its_merge(cube1, cube2);
std::vector<indexed_triangle_set> res = its_split(cube1);
REQUIRE(res.size() == 2);
REQUIRE(res[0].indices.size() == res[1].indices.size());
REQUIRE(res[0].indices.size() == cube2.indices.size());
REQUIRE(res[0].vertices.size() == res[1].vertices.size());
REQUIRE(res[0].vertices.size() == cube2.vertices.size());
debug_write_obj(res, "parts_non_watertight");
}
TEST_CASE("Split non-manifold mesh", "[its_split][its]") {
using namespace Slic3r;
auto cube = its_make_cube(10., 10., 10.), cube_low = cube;
its_transform(cube_low, identity3f().translate(Vec3f{10.f, 10.f, 10.f}));
its_merge(cube, cube_low);
its_merge_vertices(cube);
std::vector<indexed_triangle_set> res = its_split(cube);
REQUIRE(res.size() == 2);
REQUIRE(res[0].indices.size() == res[1].indices.size());
REQUIRE(res[0].indices.size() == cube_low.indices.size());
REQUIRE(res[0].vertices.size() == res[1].vertices.size());
REQUIRE(res[0].vertices.size() == cube_low.vertices.size());
debug_write_obj(res, "cubes_non_manifold");
}
TEST_CASE("Split two watertight meshes", "[its_split][its]") {
using namespace Slic3r;
auto sphere1 = its_make_sphere(10., 2 * PI / 200.), sphere2 = sphere1;
its_transform(sphere1, identity3f().translate(Vec3f{-5.f, 0.f, 0.f}));
its_transform(sphere2, identity3f().translate(Vec3f{5.f, 0.f, 0.f}));
its_merge(sphere1, sphere2);
std::vector<indexed_triangle_set> res = its_split(sphere1);
REQUIRE(res.size() == 2);
REQUIRE(res[0].indices.size() == res[1].indices.size());
REQUIRE(res[0].indices.size() == sphere2.indices.size());
REQUIRE(res[0].vertices.size() == res[1].vertices.size());
REQUIRE(res[0].vertices.size() == sphere2.vertices.size());
debug_write_obj(res, "parts_watertight");
}
#include <libslic3r/QuadricEdgeCollapse.hpp>
static float triangle_area(const Vec3f &v0, const Vec3f &v1, const Vec3f &v2)
{
Vec3f ab = v1 - v0;
Vec3f ac = v2 - v0;
return ab.cross(ac).norm() / 2.f;
}
static float triangle_area(const Vec3crd &triangle_inices, const std::vector<Vec3f> &vertices)
{
return triangle_area(vertices[triangle_inices[0]],
vertices[triangle_inices[1]],
vertices[triangle_inices[2]]);
}
#if 0
// clang complains about unused functions
static std::mt19937 create_random_generator() {
std::random_device rd;
std::mt19937 gen(rd());
return gen;
}
#endif
std::vector<Vec3f> its_sample_surface(const indexed_triangle_set &its,
double sample_per_mm2,
std::mt19937 random_generator) // = create_random_generator())
{
std::vector<Vec3f> samples;
std::uniform_real_distribution<float> rand01(0.f, 1.f);
for (const auto &triangle_indices : its.indices) {
float area = triangle_area(triangle_indices, its.vertices);
float countf;
float fractional = std::modf(area * sample_per_mm2, &countf);
int count = static_cast<int>(countf);
float generate = rand01(random_generator);
if (generate < fractional) ++count;
if (count == 0) continue;
const Vec3f &v0 = its.vertices[triangle_indices[0]];
const Vec3f &v1 = its.vertices[triangle_indices[1]];
const Vec3f &v2 = its.vertices[triangle_indices[2]];
for (int c = 0; c < count; c++) {
// barycentric coordinate
Vec3f b;
b[0] = rand01(random_generator);
b[1] = rand01(random_generator);
if ((b[0] + b[1]) > 1.f) {
b[0] = 1.f - b[0];
b[1] = 1.f - b[1];
}
b[2] = 1.f - b[0] - b[1];
Vec3f pos;
for (int i = 0; i < 3; i++) {
pos[i] = b[0] * v0[i] + b[1] * v1[i] + b[2] * v2[i];
}
samples.push_back(pos);
}
}
return samples;
}
#include "libslic3r/AABBTreeIndirect.hpp"
struct CompareConfig
{
float max_distance = 3.f;
float max_average_distance = 2.f;
};
bool is_similar(const indexed_triangle_set &from,
const indexed_triangle_set &to,
const CompareConfig &cfg)
{
// create ABBTree
auto tree = AABBTreeIndirect::build_aabb_tree_over_indexed_triangle_set(
from.vertices, from.indices);
float sum_distance = 0.f;
float max_distance = 0.f;
auto collect_distances = [&](const Vec3f &surface_point) {
size_t hit_idx;
Vec3f hit_point;
float distance2 =
AABBTreeIndirect::squared_distance_to_indexed_triangle_set(
from.vertices, from.indices, tree, surface_point, hit_idx, hit_point);
float distance = sqrt(distance2);
if (max_distance < distance) max_distance = distance;
sum_distance += distance;
};
for (const Vec3f &vertex : to.vertices) {
collect_distances(vertex);
}
for (const Vec3i &t : to.indices) {
Vec3f center(0,0,0);
for (size_t i = 0; i < 3; ++i) {
center += to.vertices[t[i]] / 3;
}
collect_distances(center);
}
size_t count = to.vertices.size() + to.indices.size();
float avg_distance = sum_distance / count;
if (avg_distance > cfg.max_average_distance ||
max_distance > cfg.max_distance)
return false;
return true;
}
#include "test_utils.hpp"
TEST_CASE("Simplify mesh by Quadric edge collapse to 5%", "[its]")
{
TriangleMesh mesh = load_model("frog_legs.obj");
double original_volume = its_volume(mesh.its);
uint32_t wanted_count = mesh.its.indices.size() * 0.05;
REQUIRE_FALSE(mesh.empty());
indexed_triangle_set its = mesh.its; // copy
float max_error = std::numeric_limits<float>::max();
its_quadric_edge_collapse(its, wanted_count, &max_error);
//its_write_obj(its, "frog_legs_qec.obj");
CHECK(its.indices.size() <= wanted_count);
double volume = its_volume(its);
CHECK(fabs(original_volume - volume) < 33.);
CompareConfig cfg;
cfg.max_average_distance = 0.043f;
cfg.max_distance = 0.32f;
CHECK(is_similar(mesh.its, its, cfg));
CHECK(is_similar(its, mesh.its, cfg));
}
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