Add tests for EigenMesh3D raycaster with hole support.

Tests fail! Supports are intersecting the object when holes are added.

src/libslic3r/SLA/Hollowing.cpp

@@ -6,6 +6,7 @@
 #include <libslic3r/SLA/Contour3D.hpp>
 #include <libslic3r/SLA/EigenMesh3D.hpp>
 #include <libslic3r/SLA/SupportTreeBuilder.hpp>
+#include <libslic3r/ClipperUtils.hpp>
 
 #include <boost/log/trivial.hpp>
 
@@ -247,4 +248,40 @@ bool DrainHole::get_intersections(const Vec3f& s, const Vec3f& dir,
     return true;
 }
 
+void cut_drainholes(std::vector<ExPolygons> & obj_slices,
+                    const std::vector<float> &slicegrid,
+                    float                     closing_radius,
+                    const sla::DrainHoles &   holes,
+                    std::function<void(void)> thr)
+{
+    TriangleMesh mesh;
+    for (const sla::DrainHole &holept : holes) {
+        auto r = double(holept.radius);
+        auto h = double(holept.height);
+        sla::Contour3D hole = sla::cylinder(r, h);
+        Eigen::Quaterniond q;
+        q.setFromTwoVectors(Vec3d{0., 0., 1.}, holept.normal.cast<double>());
+        for(auto& p : hole.points) p = q * p + holept.pos.cast<double>();
+        mesh.merge(sla::to_triangle_mesh(hole));
+    }
+    
+    if (mesh.empty()) return;
+    
+    mesh.require_shared_vertices();
+    
+    TriangleMeshSlicer slicer(&mesh);
+    
+    std::vector<ExPolygons> hole_slices;
+    slicer.slice(slicegrid, closing_radius, &hole_slices, thr);
+    
+    if (obj_slices.size() != hole_slices.size())
+        BOOST_LOG_TRIVIAL(warning)
+            << "Sliced object and drain-holes layer count does not match!";
+
+    size_t until = std::min(obj_slices.size(), hole_slices.size());
+    
+    for (size_t i = 0; i < until; ++i)
+        obj_slices[i] = diff_ex(obj_slices[i], hole_slices[i]);
+}
+
 }} // namespace Slic3r::sla

src/libslic3r/SLA/Hollowing.hpp

@@ -17,6 +17,7 @@ struct HollowingConfig
     double min_thickness    = 2.;
     double quality          = 0.5;
     double closing_distance = 0.5;
+    bool enabled = true;
 };
 
 struct DrainHole
@@ -57,6 +58,12 @@ std::unique_ptr<TriangleMesh> generate_interior(const TriangleMesh &mesh,
                                                 const HollowingConfig &  = {},
                                                 const JobController &ctl = {});
 
+void cut_drainholes(std::vector<ExPolygons> & obj_slices,
+                    const std::vector<float> &slicegrid,
+                    float                     closing_radius,
+                    const sla::DrainHoles &   holes,
+                    std::function<void(void)> thr);
+
 }
 }
 

src/libslic3r/SLAPrintSteps.cpp

@@ -79,7 +79,6 @@ SLAPrint::Steps::Steps(SLAPrint *print)
 
 void SLAPrint::Steps::hollow_model(SLAPrintObject &po)
 {
-    
     if (!po.m_config.hollowing_enable.getBool()) {
         BOOST_LOG_TRIVIAL(info) << "Skipping hollowing step!";
         po.m_hollowing_data.reset();
@@ -102,42 +101,6 @@ void SLAPrint::Steps::hollow_model(SLAPrintObject &po)
         BOOST_LOG_TRIVIAL(warning) << "Hollowed interior is empty!";
 }
 
-static void cut_drainholes(std::vector<ExPolygons> & obj_slices,
-                           const std::vector<float> &slicegrid,
-                           float                     closing_radius,
-                           const sla::DrainHoles &   holes,
-                           std::function<void(void)> thr)
-{
-    TriangleMesh mesh;
-    for (const sla::DrainHole &holept : holes) {
-        auto r = double(holept.radius);
-        auto h = double(holept.height);
-        sla::Contour3D hole = sla::cylinder(r, h);
-        Eigen::Quaterniond q;
-        q.setFromTwoVectors(Vec3d{0., 0., 1.}, holept.normal.cast<double>());
-        for(auto& p : hole.points) p = q * p + holept.pos.cast<double>();
-        mesh.merge(sla::to_triangle_mesh(hole));
-    }
-    
-    if (mesh.empty()) return;
-    
-    mesh.require_shared_vertices();
-    
-    TriangleMeshSlicer slicer(&mesh);
-    
-    std::vector<ExPolygons> hole_slices;
-    slicer.slice(slicegrid, closing_radius, &hole_slices, thr);
-    
-    if (obj_slices.size() != hole_slices.size())
-        BOOST_LOG_TRIVIAL(warning)
-            << "Sliced object and drain-holes layer count does not match!";
-
-    size_t until = std::min(obj_slices.size(), hole_slices.size());
-    
-    for (size_t i = 0; i < until; ++i)
-        obj_slices[i] = diff_ex(obj_slices[i], hole_slices[i]);
-}
-
 // The slicing will be performed on an imaginary 1D grid which starts from
 // the bottom of the bounding box created around the supported model. So
 // the first layer which is usually thicker will be part of the supports

tests/sla_print/CMakeLists.txt

@@ -1,5 +1,8 @@
 get_filename_component(_TEST_NAME ${CMAKE_CURRENT_LIST_DIR} NAME)
-add_executable(${_TEST_NAME}_tests ${_TEST_NAME}_tests_main.cpp sla_print_tests.cpp)
+add_executable(${_TEST_NAME}_tests ${_TEST_NAME}_tests_main.cpp 
+    sla_print_tests.cpp 
+    sla_test_utils.hpp sla_test_utils.cpp
+    sla_raycast_tests.cpp)
 target_link_libraries(${_TEST_NAME}_tests test_common libslic3r)
 set_property(TARGET ${_TEST_NAME}_tests PROPERTY FOLDER "tests")
 

tests/sla_print/sla_print_tests.cpp

@@ -2,369 +2,9 @@
 #include <unordered_map>
 #include <random>
 
-#include <catch2/catch.hpp>
+#include "sla_test_utils.hpp"
-
-// Debug
-#include <fstream>
-
-#include "libslic3r/libslic3r.h"
-#include "libslic3r/Format/OBJ.hpp"
-#include "libslic3r/SLAPrint.hpp"
-#include "libslic3r/TriangleMesh.hpp"
-#include "libslic3r/SLA/Pad.hpp"
-#include "libslic3r/SLA/SupportTreeBuilder.hpp"
-#include "libslic3r/SLA/SupportTreeBuildsteps.hpp"
-#include "libslic3r/SLA/SupportPointGenerator.hpp"
-#include "libslic3r/SLA/Raster.hpp"
-#include "libslic3r/SLA/ConcaveHull.hpp"
-#include "libslic3r/MTUtils.hpp"
-
-#include "libslic3r/SVG.hpp"
-#include "libslic3r/Format/OBJ.hpp"
-
-#if defined(WIN32) || defined(_WIN32)
-#define PATH_SEPARATOR R"(\)"
-#else
-#define PATH_SEPARATOR R"(/)"
-#endif
 
 namespace {
-using namespace Slic3r;
-
-TriangleMesh load_model(const std::string &obj_filename)
-{
-    TriangleMesh mesh;
-    auto fpath = TEST_DATA_DIR PATH_SEPARATOR + obj_filename;
-    load_obj(fpath.c_str(), &mesh);
-    return mesh;
-}
-
-enum e_validity {
-    ASSUME_NO_EMPTY = 1,
-    ASSUME_MANIFOLD = 2,
-    ASSUME_NO_REPAIR = 4
-};
-
-void check_validity(const TriangleMesh &input_mesh,
-                    int flags = ASSUME_NO_EMPTY | ASSUME_MANIFOLD |
-                                ASSUME_NO_REPAIR)
-{
-    TriangleMesh mesh{input_mesh};
-    
-    if (flags & ASSUME_NO_EMPTY) {
-        REQUIRE_FALSE(mesh.empty());
-    } else if (mesh.empty())
-        return; // If it can be empty and it is, there is nothing left to do.
-    
-    REQUIRE(stl_validate(&mesh.stl));
-    
-    bool do_update_shared_vertices = false;
-    mesh.repair(do_update_shared_vertices);
-    
-    if (flags & ASSUME_NO_REPAIR) {
-        REQUIRE_FALSE(mesh.needed_repair());
-    }
-    
-    if (flags & ASSUME_MANIFOLD) {
-        mesh.require_shared_vertices();
-        if (!mesh.is_manifold()) mesh.WriteOBJFile("non_manifold.obj");
-        REQUIRE(mesh.is_manifold());
-    }
-}
-
-struct PadByproducts
-{
-    ExPolygons   model_contours;
-    ExPolygons   support_contours;
-    TriangleMesh mesh;
-};
-
-void _test_concave_hull(const Polygons &hull, const ExPolygons &polys)
-{
-    REQUIRE(polys.size() >=hull.size());
-    
-    double polys_area = 0;
-    for (const ExPolygon &p : polys) polys_area += p.area();
-    
-    double cchull_area = 0;
-    for (const Slic3r::Polygon &p : hull) cchull_area += p.area();
-    
-    REQUIRE(cchull_area >= Approx(polys_area));
-    
-    size_t cchull_holes = 0;
-    for (const Slic3r::Polygon &p : hull)
-        cchull_holes += p.is_clockwise() ? 1 : 0;
-    
-    REQUIRE(cchull_holes == 0);
-    
-    Polygons intr = diff(to_polygons(polys), hull);
-    REQUIRE(intr.empty());
-}
-
-void test_concave_hull(const ExPolygons &polys) {
-    sla::PadConfig pcfg;
-    
-    Slic3r::sla::ConcaveHull cchull{polys, pcfg.max_merge_dist_mm, []{}};
-    
-    _test_concave_hull(cchull.polygons(), polys);
-    
-    coord_t delta = scaled(pcfg.brim_size_mm + pcfg.wing_distance());
-    ExPolygons wafflex = sla::offset_waffle_style_ex(cchull, delta);
-    Polygons waffl = sla::offset_waffle_style(cchull, delta);
-    
-    _test_concave_hull(to_polygons(wafflex), polys);
-    _test_concave_hull(waffl, polys);
-}
-
-void test_pad(const std::string &   obj_filename,
-              const sla::PadConfig &padcfg,
-              PadByproducts &       out)
-{
-    REQUIRE(padcfg.validate().empty());
-    
-    TriangleMesh mesh = load_model(obj_filename);
-    
-    REQUIRE_FALSE(mesh.empty());
-    
-    // Create pad skeleton only from the model
-    Slic3r::sla::pad_blueprint(mesh, out.model_contours);
-    
-    test_concave_hull(out.model_contours);
-    
-    REQUIRE_FALSE(out.model_contours.empty());
-    
-    // Create the pad geometry for the model contours only
-    Slic3r::sla::create_pad({}, out.model_contours, out.mesh, padcfg);
-    
-    check_validity(out.mesh);
-    
-    auto bb = out.mesh.bounding_box();
-    REQUIRE(bb.max.z() - bb.min.z() == Approx(padcfg.full_height()));
-}
-
-void test_pad(const std::string &   obj_filename,
-              const sla::PadConfig &padcfg = {})
-{
-    PadByproducts byproducts;
-    test_pad(obj_filename, padcfg, byproducts);
-}
-
-struct SupportByproducts
-{
-    std::string             obj_fname;
-    std::vector<float>      slicegrid;
-    std::vector<ExPolygons> model_slices;
-    sla::SupportTreeBuilder supporttree;
-    TriangleMesh            input_mesh;
-};
-
-const constexpr float CLOSING_RADIUS = 0.005f;
-
-void check_support_tree_integrity(const sla::SupportTreeBuilder &stree,
-                                  const sla::SupportConfig &cfg)
-{
-    double gnd  = stree.ground_level;
-    double H1   = cfg.max_solo_pillar_height_mm;
-    double H2   = cfg.max_dual_pillar_height_mm;
-    
-    for (const sla::Head &head : stree.heads()) {
-        REQUIRE((!head.is_valid() || head.pillar_id != sla::ID_UNSET ||
-                 head.bridge_id != sla::ID_UNSET));
-    }
-    
-    for (const sla::Pillar &pillar : stree.pillars()) {
-        if (std::abs(pillar.endpoint().z() - gnd) < EPSILON) {
-            double h = pillar.height;
-            
-            if (h > H1) REQUIRE(pillar.links >= 1);
-            else if(h > H2) { REQUIRE(pillar.links >= 2); }
-        }
-        
-        REQUIRE(pillar.links <= cfg.pillar_cascade_neighbors);
-        REQUIRE(pillar.bridges <= cfg.max_bridges_on_pillar);
-    }
-    
-    double max_bridgelen = 0.;
-    auto chck_bridge = [&cfg](const sla::Bridge &bridge, double &max_brlen) {
-        Vec3d n = bridge.endp - bridge.startp;
-        double d = sla::distance(n);
-        max_brlen = std::max(d, max_brlen);
-        
-        double z     = n.z();
-        double polar = std::acos(z / d);
-        double slope = -polar + PI / 2.;
-        REQUIRE(std::abs(slope) >= cfg.bridge_slope - EPSILON);
-    };
-    
-    for (auto &bridge : stree.bridges()) chck_bridge(bridge, max_bridgelen);
-    REQUIRE(max_bridgelen <= cfg.max_bridge_length_mm);
-    
-    max_bridgelen = 0;
-    for (auto &bridge : stree.crossbridges()) chck_bridge(bridge, max_bridgelen);
-    
-    double md = cfg.max_pillar_link_distance_mm / std::cos(-cfg.bridge_slope);
-    REQUIRE(max_bridgelen <= md);
-}
-
-void test_supports(const std::string &       obj_filename,
-                   const sla::SupportConfig &supportcfg,
-                   SupportByproducts &       out)
-{
-    using namespace Slic3r;
-    TriangleMesh mesh = load_model(obj_filename);
-    
-    REQUIRE_FALSE(mesh.empty());
-    
-    TriangleMeshSlicer slicer{&mesh};
-    
-    auto   bb      = mesh.bounding_box();
-    double zmin    = bb.min.z();
-    double zmax    = bb.max.z();
-    double gnd     = zmin - supportcfg.object_elevation_mm;
-    auto   layer_h = 0.05f;
-    
-    out.slicegrid = grid(float(gnd), float(zmax), layer_h);
-    slicer.slice(out.slicegrid , CLOSING_RADIUS, &out.model_slices, []{});
-    
-    // Create the special index-triangle mesh with spatial indexing which
-    // is the input of the support point and support mesh generators
-    sla::EigenMesh3D emesh{mesh};
-    
-    // Create the support point generator
-    sla::SupportPointGenerator::Config autogencfg;
-    autogencfg.head_diameter = float(2 * supportcfg.head_front_radius_mm);
-    sla::SupportPointGenerator point_gen{emesh,         out.model_slices,
-                                         out.slicegrid, autogencfg,
-                                         [] {},         [](int) {}};
-
-    // Get the calculated support points.
-    std::vector<sla::SupportPoint> support_points = point_gen.output();
-    
-    int validityflags = ASSUME_NO_REPAIR;
-    
-    // If there is no elevation, support points shall be removed from the
-    // bottom of the object.
-    if (std::abs(supportcfg.object_elevation_mm) < EPSILON) {
-        sla::remove_bottom_points(support_points, zmin,
-                                  supportcfg.base_height_mm);
-    } else {
-        // Should be support points at least on the bottom of the model
-        REQUIRE_FALSE(support_points.empty());
-        
-        // Also the support mesh should not be empty.
-        validityflags |= ASSUME_NO_EMPTY;
-    }
-    
-    // Generate the actual support tree
-    sla::SupportTreeBuilder treebuilder;
-    treebuilder.build(sla::SupportableMesh{emesh, support_points, supportcfg});
-    
-    check_support_tree_integrity(treebuilder, supportcfg);
-    
-    const TriangleMesh &output_mesh = treebuilder.retrieve_mesh();
-    
-    check_validity(output_mesh, validityflags);
-    
-    // Quick check if the dimensions and placement of supports are correct
-    auto obb = output_mesh.bounding_box();
-    
-    double allowed_zmin = zmin - supportcfg.object_elevation_mm;
-    
-    if (std::abs(supportcfg.object_elevation_mm) < EPSILON)
-        allowed_zmin = zmin - 2 * supportcfg.head_back_radius_mm;
-    
-    REQUIRE(obb.min.z() >= allowed_zmin);
-    REQUIRE(obb.max.z() <= zmax);
-    
-    // Move out the support tree into the byproducts, we can examine it further
-    // in various tests.
-    out.obj_fname   = std::move(obj_filename);
-    out.supporttree = std::move(treebuilder);
-    out.input_mesh  = std::move(mesh);
-}
-
-void test_supports(const std::string &       obj_filename,
-                   const sla::SupportConfig &supportcfg = {})
-{
-    SupportByproducts byproducts;
-    test_supports(obj_filename, supportcfg, byproducts);
-}
-
-void export_failed_case(const std::vector<ExPolygons> &support_slices,
-                        const SupportByproducts &byproducts)
-{
-    for (size_t n = 0; n < support_slices.size(); ++n) {
-        const ExPolygons &sup_slice = support_slices[n];
-        const ExPolygons &mod_slice = byproducts.model_slices[n];
-        Polygons intersections = intersection(sup_slice, mod_slice);
-        
-        std::stringstream ss;
-        if (!intersections.empty()) {
-            ss << byproducts.obj_fname << std::setprecision(4) << n << ".svg";
-            SVG svg(ss.str());
-            svg.draw(sup_slice, "green");
-            svg.draw(mod_slice, "blue");
-            svg.draw(intersections, "red");
-            svg.Close();
-        }
-    }
-    
-    TriangleMesh m;
-    byproducts.supporttree.retrieve_full_mesh(m);
-    m.merge(byproducts.input_mesh);
-    m.repair();
-    m.require_shared_vertices();
-    m.WriteOBJFile(byproducts.obj_fname.c_str());
-}
-
-void test_support_model_collision(
-    const std::string &       obj_filename,
-    const sla::SupportConfig &input_supportcfg = {})
-{
-    SupportByproducts byproducts;
-    
-    sla::SupportConfig supportcfg = input_supportcfg;
-    
-    // Set head penetration to a small negative value which should ensure that
-    // the supports will not touch the model body.
-    supportcfg.head_penetration_mm = -0.15;
-    
-    // TODO: currently, the tailheads penetrating into the model body do not
-    // respect the penetration parameter properly. No issues were reported so
-    // far but we should definitely fix this.
-    supportcfg.ground_facing_only = true;
-    
-    test_supports(obj_filename, supportcfg, byproducts);
-    
-    // Slice the support mesh given the slice grid of the model.
-    std::vector<ExPolygons> support_slices =
-        byproducts.supporttree.slice(byproducts.slicegrid, CLOSING_RADIUS);
-    
-    // The slices originate from the same slice grid so the numbers must match
-    
-    bool support_mesh_is_empty =
-        byproducts.supporttree.retrieve_mesh(sla::MeshType::Pad).empty() &&
-        byproducts.supporttree.retrieve_mesh(sla::MeshType::Support).empty();
-    
-    if (support_mesh_is_empty)
-        REQUIRE(support_slices.empty());
-    else
-        REQUIRE(support_slices.size() == byproducts.model_slices.size());
-    
-    bool notouch = true;
-    for (size_t n = 0; notouch && n < support_slices.size(); ++n) {
-        const ExPolygons &sup_slice = support_slices[n];
-        const ExPolygons &mod_slice = byproducts.model_slices[n];
-        
-        Polygons intersections = intersection(sup_slice, mod_slice);
-        
-        notouch = notouch && intersections.empty();
-    }
-    
-    if (!notouch) export_failed_case(support_slices, byproducts);
-    
-    REQUIRE(notouch);
-}
 
 const char *const BELOW_PAD_TEST_OBJECTS[] = {
     "20mm_cube.obj",

tests/sla_print/sla_raycast_tests.cpp

@@ -0,0 +1,61 @@
+#include <catch2/catch.hpp>
+#include <test_utils.hpp>
+
+#include <libslic3r/SLA/EigenMesh3D.hpp>
+#include <libslic3r/SLA/Hollowing.hpp>
+
+#include "sla_test_utils.hpp"
+
+using namespace Slic3r;
+
+// Create a simple scene with a 20mm cube and a big hole in the front wall 
+// with 5mm radius. Then shoot rays from interesting positions and see where
+// they land.
+TEST_CASE("Raycaster with loaded drillholes", "[sla_raycast]") 
+{
+    // Load the cube and make it hollow.
+    TriangleMesh cube = load_model("20mm_cube.obj");
+    sla::HollowingConfig hcfg;
+    std::unique_ptr<TriangleMesh> cube_inside = sla::generate_interior(cube, hcfg);
+    REQUIRE(cube_inside);
+    
+    // Helper bb
+    auto boxbb = cube.bounding_box();
+    
+    // Create the big 10mm long drainhole in the front wall.
+    Vec3f center = boxbb.center().cast<float>();
+    Vec3f p = {center.x(), 0., center.z()};
+    Vec3f normal = {0.f, 1.f, 0.f};
+    float radius = 5.f;
+    float hole_length = 10.;
+    sla::DrainHoles holes = { sla::DrainHole{p, normal, radius, hole_length} };
+    
+    cube.merge(*cube_inside);
+    cube.require_shared_vertices();
+    
+    sla::EigenMesh3D emesh{cube};
+    emesh.load_holes(holes);
+    
+    Vec3d s = center.cast<double>();
+    SECTION("Fire from center, should hit the interior wall") {
+        auto hit = emesh.query_ray_hit(s, {0, 1., 0.});
+        REQUIRE(hit.distance() == Approx(boxbb.size().x() / 2 - hcfg.min_thickness));
+    }
+    
+    SECTION("Fire upward from hole center, hit distance equals the radius") {
+        s.y() = hcfg.min_thickness / 2;
+        auto hit = emesh.query_ray_hit(s, {0, 0., 1.});
+        REQUIRE(hit.distance() == Approx(radius));
+    }
+    
+    // Shouldn't this hit the inside wall through the hole?
+    SECTION("Fire from outside, hit the back side of the hole cylinder.") {
+        s.y() = -1.;
+        auto hit = emesh.query_ray_hit(s, {0, 1., 0.});
+        REQUIRE(hit.distance() == Approx(hole_length + 1.f));
+    }
+    
+    SECTION("Check for support tree correctness") {
+        test_support_model_collision("20mm_cube.obj", {}, hcfg, holes);
+    }
+}

tests/sla_print/sla_test_utils.cpp

@@ -0,0 +1,297 @@
+#include "sla_test_utils.hpp"
+
+void test_support_model_collision(const std::string          &obj_filename,
+                                  const sla::SupportConfig   &input_supportcfg,
+                                  const sla::HollowingConfig &hollowingcfg,
+                                  const sla::DrainHoles      &drainholes)
+{
+    SupportByproducts byproducts;
+    
+    sla::SupportConfig supportcfg = input_supportcfg;
+    
+    // Set head penetration to a small negative value which should ensure that
+    // the supports will not touch the model body.
+    supportcfg.head_penetration_mm = -0.15;
+    
+    // TODO: currently, the tailheads penetrating into the model body do not
+    // respect the penetration parameter properly. No issues were reported so
+    // far but we should definitely fix this.
+    supportcfg.ground_facing_only = true;
+    
+    test_supports(obj_filename, supportcfg, hollowingcfg, drainholes, byproducts);
+    
+    // Slice the support mesh given the slice grid of the model.
+    std::vector<ExPolygons> support_slices =
+            byproducts.supporttree.slice(byproducts.slicegrid, CLOSING_RADIUS);
+    
+    // The slices originate from the same slice grid so the numbers must match
+    
+    bool support_mesh_is_empty =
+            byproducts.supporttree.retrieve_mesh(sla::MeshType::Pad).empty() &&
+            byproducts.supporttree.retrieve_mesh(sla::MeshType::Support).empty();
+    
+    if (support_mesh_is_empty)
+        REQUIRE(support_slices.empty());
+    else
+        REQUIRE(support_slices.size() == byproducts.model_slices.size());
+    
+    bool notouch = true;
+    for (size_t n = 0; notouch && n < support_slices.size(); ++n) {
+        const ExPolygons &sup_slice = support_slices[n];
+        const ExPolygons &mod_slice = byproducts.model_slices[n];
+        
+        Polygons intersections = intersection(sup_slice, mod_slice);
+        
+        notouch = notouch && intersections.empty();
+    }
+    
+    /*if (!notouch) */export_failed_case(support_slices, byproducts);
+    
+    REQUIRE(notouch);
+}
+
+void export_failed_case(const std::vector<ExPolygons> &support_slices, const SupportByproducts &byproducts)
+{
+    for (size_t n = 0; n < support_slices.size(); ++n) {
+        const ExPolygons &sup_slice = support_slices[n];
+        const ExPolygons &mod_slice = byproducts.model_slices[n];
+        Polygons intersections = intersection(sup_slice, mod_slice);
+        
+        std::stringstream ss;
+        if (!intersections.empty()) {
+            ss << byproducts.obj_fname << std::setprecision(4) << n << ".svg";
+            SVG svg(ss.str());
+            svg.draw(sup_slice, "green");
+            svg.draw(mod_slice, "blue");
+            svg.draw(intersections, "red");
+            svg.Close();
+        }
+    }
+    
+    TriangleMesh m;
+    byproducts.supporttree.retrieve_full_mesh(m);
+    m.merge(byproducts.input_mesh);
+    m.repair();
+    m.require_shared_vertices();
+    m.WriteOBJFile(byproducts.obj_fname.c_str());
+}
+
+void test_supports(const std::string          &obj_filename,
+                   const sla::SupportConfig   &supportcfg,
+                   const sla::HollowingConfig &hollowingcfg,
+                   const sla::DrainHoles      &drainholes,
+                   SupportByproducts          &out)
+{
+    using namespace Slic3r;
+    TriangleMesh mesh = load_model(obj_filename);
+    
+    REQUIRE_FALSE(mesh.empty());
+    
+    if (hollowingcfg.enabled) {
+        auto inside = sla::generate_interior(mesh, hollowingcfg);
+        REQUIRE(inside);
+        mesh.merge(*inside);
+        mesh.require_shared_vertices();
+    }
+    
+    TriangleMeshSlicer slicer{&mesh};
+    
+    auto   bb      = mesh.bounding_box();
+    double zmin    = bb.min.z();
+    double zmax    = bb.max.z();
+    double gnd     = zmin - supportcfg.object_elevation_mm;
+    auto   layer_h = 0.05f;
+    
+    out.slicegrid = grid(float(gnd), float(zmax), layer_h);
+    slicer.slice(out.slicegrid , CLOSING_RADIUS, &out.model_slices, []{});
+    sla::cut_drainholes(out.model_slices, out.slicegrid, CLOSING_RADIUS, drainholes, []{});
+    
+    // Create the special index-triangle mesh with spatial indexing which
+    // is the input of the support point and support mesh generators
+    sla::EigenMesh3D emesh{mesh};
+    if (hollowingcfg.enabled) 
+        emesh.load_holes(drainholes);
+    
+    // Create the support point generator
+    sla::SupportPointGenerator::Config autogencfg;
+    autogencfg.head_diameter = float(2 * supportcfg.head_front_radius_mm);
+    sla::SupportPointGenerator point_gen{emesh, out.model_slices, out.slicegrid, 
+                autogencfg, [] {}, [](int) {}};
+    
+    // Get the calculated support points.
+    std::vector<sla::SupportPoint> support_points = point_gen.output();
+    
+    int validityflags = ASSUME_NO_REPAIR;
+    
+    // If there is no elevation, support points shall be removed from the
+    // bottom of the object.
+    if (std::abs(supportcfg.object_elevation_mm) < EPSILON) {
+        sla::remove_bottom_points(support_points, zmin,
+                                  supportcfg.base_height_mm);
+    } else {
+        // Should be support points at least on the bottom of the model
+        REQUIRE_FALSE(support_points.empty());
+        
+        // Also the support mesh should not be empty.
+        validityflags |= ASSUME_NO_EMPTY;
+    }
+    
+    // Generate the actual support tree
+    sla::SupportTreeBuilder treebuilder;
+    treebuilder.build(sla::SupportableMesh{emesh, support_points, supportcfg});
+    
+    check_support_tree_integrity(treebuilder, supportcfg);
+    
+    const TriangleMesh &output_mesh = treebuilder.retrieve_mesh();
+    
+    check_validity(output_mesh, validityflags);
+    
+    // Quick check if the dimensions and placement of supports are correct
+    auto obb = output_mesh.bounding_box();
+    
+    double allowed_zmin = zmin - supportcfg.object_elevation_mm;
+    
+    if (std::abs(supportcfg.object_elevation_mm) < EPSILON)
+        allowed_zmin = zmin - 2 * supportcfg.head_back_radius_mm;
+    
+    REQUIRE(obb.min.z() >= allowed_zmin);
+    REQUIRE(obb.max.z() <= zmax);
+    
+    // Move out the support tree into the byproducts, we can examine it further
+    // in various tests.
+    out.obj_fname   = std::move(obj_filename);
+    out.supporttree = std::move(treebuilder);
+    out.input_mesh  = std::move(mesh);
+}
+
+void check_support_tree_integrity(const sla::SupportTreeBuilder &stree, 
+                                  const sla::SupportConfig &cfg)
+{
+    double gnd  = stree.ground_level;
+    double H1   = cfg.max_solo_pillar_height_mm;
+    double H2   = cfg.max_dual_pillar_height_mm;
+    
+    for (const sla::Head &head : stree.heads()) {
+        REQUIRE((!head.is_valid() || head.pillar_id != sla::ID_UNSET ||
+                head.bridge_id != sla::ID_UNSET));
+    }
+    
+    for (const sla::Pillar &pillar : stree.pillars()) {
+        if (std::abs(pillar.endpoint().z() - gnd) < EPSILON) {
+            double h = pillar.height;
+            
+            if (h > H1) REQUIRE(pillar.links >= 1);
+            else if(h > H2) { REQUIRE(pillar.links >= 2); }
+        }
+        
+        REQUIRE(pillar.links <= cfg.pillar_cascade_neighbors);
+        REQUIRE(pillar.bridges <= cfg.max_bridges_on_pillar);
+    }
+    
+    double max_bridgelen = 0.;
+    auto chck_bridge = [&cfg](const sla::Bridge &bridge, double &max_brlen) {
+        Vec3d n = bridge.endp - bridge.startp;
+        double d = sla::distance(n);
+        max_brlen = std::max(d, max_brlen);
+        
+        double z     = n.z();
+        double polar = std::acos(z / d);
+        double slope = -polar + PI / 2.;
+        REQUIRE(std::abs(slope) >= cfg.bridge_slope - EPSILON);
+    };
+    
+    for (auto &bridge : stree.bridges()) chck_bridge(bridge, max_bridgelen);
+    REQUIRE(max_bridgelen <= cfg.max_bridge_length_mm);
+    
+    max_bridgelen = 0;
+    for (auto &bridge : stree.crossbridges()) chck_bridge(bridge, max_bridgelen);
+    
+    double md = cfg.max_pillar_link_distance_mm / std::cos(-cfg.bridge_slope);
+    REQUIRE(max_bridgelen <= md);
+}
+
+void test_pad(const std::string &obj_filename, const sla::PadConfig &padcfg, PadByproducts &out)
+{
+    REQUIRE(padcfg.validate().empty());
+    
+    TriangleMesh mesh = load_model(obj_filename);
+    
+    REQUIRE_FALSE(mesh.empty());
+    
+    // Create pad skeleton only from the model
+    Slic3r::sla::pad_blueprint(mesh, out.model_contours);
+    
+    test_concave_hull(out.model_contours);
+    
+    REQUIRE_FALSE(out.model_contours.empty());
+    
+    // Create the pad geometry for the model contours only
+    Slic3r::sla::create_pad({}, out.model_contours, out.mesh, padcfg);
+    
+    check_validity(out.mesh);
+    
+    auto bb = out.mesh.bounding_box();
+    REQUIRE(bb.max.z() - bb.min.z() == Approx(padcfg.full_height()));
+}
+
+static void _test_concave_hull(const Polygons &hull, const ExPolygons &polys)
+{
+    REQUIRE(polys.size() >=hull.size());
+    
+    double polys_area = 0;
+    for (const ExPolygon &p : polys) polys_area += p.area();
+    
+    double cchull_area = 0;
+    for (const Slic3r::Polygon &p : hull) cchull_area += p.area();
+    
+    REQUIRE(cchull_area >= Approx(polys_area));
+    
+    size_t cchull_holes = 0;
+    for (const Slic3r::Polygon &p : hull)
+        cchull_holes += p.is_clockwise() ? 1 : 0;
+    
+    REQUIRE(cchull_holes == 0);
+    
+    Polygons intr = diff(to_polygons(polys), hull);
+    REQUIRE(intr.empty());
+}
+
+void test_concave_hull(const ExPolygons &polys) {
+    sla::PadConfig pcfg;
+    
+    Slic3r::sla::ConcaveHull cchull{polys, pcfg.max_merge_dist_mm, []{}};
+    
+    _test_concave_hull(cchull.polygons(), polys);
+    
+    coord_t delta = scaled(pcfg.brim_size_mm + pcfg.wing_distance());
+    ExPolygons wafflex = sla::offset_waffle_style_ex(cchull, delta);
+    Polygons waffl = sla::offset_waffle_style(cchull, delta);
+    
+    _test_concave_hull(to_polygons(wafflex), polys);
+    _test_concave_hull(waffl, polys);
+}
+
+void check_validity(const TriangleMesh &input_mesh, int flags)
+{
+    TriangleMesh mesh{input_mesh};
+    
+    if (flags & ASSUME_NO_EMPTY) {
+        REQUIRE_FALSE(mesh.empty());
+    } else if (mesh.empty())
+        return; // If it can be empty and it is, there is nothing left to do.
+    
+    REQUIRE(stl_validate(&mesh.stl));
+    
+    bool do_update_shared_vertices = false;
+    mesh.repair(do_update_shared_vertices);
+    
+    if (flags & ASSUME_NO_REPAIR) {
+        REQUIRE_FALSE(mesh.needed_repair());
+    }
+    
+    if (flags & ASSUME_MANIFOLD) {
+        mesh.require_shared_vertices();
+        if (!mesh.is_manifold()) mesh.WriteOBJFile("non_manifold.obj");
+        REQUIRE(mesh.is_manifold());
+    }
+}

tests/sla_print/sla_test_utils.hpp

@@ -0,0 +1,112 @@
+#ifndef SLA_TEST_UTILS_HPP
+#define SLA_TEST_UTILS_HPP
+
+#include <catch2/catch.hpp>
+#include <test_utils.hpp>
+
+// Debug
+#include <fstream>
+
+#include "libslic3r/libslic3r.h"
+#include "libslic3r/Format/OBJ.hpp"
+#include "libslic3r/SLAPrint.hpp"
+#include "libslic3r/TriangleMesh.hpp"
+#include "libslic3r/SLA/Pad.hpp"
+#include "libslic3r/SLA/SupportTreeBuilder.hpp"
+#include "libslic3r/SLA/SupportTreeBuildsteps.hpp"
+#include "libslic3r/SLA/SupportPointGenerator.hpp"
+#include "libslic3r/SLA/Raster.hpp"
+#include "libslic3r/SLA/ConcaveHull.hpp"
+#include "libslic3r/MTUtils.hpp"
+
+#include "libslic3r/SVG.hpp"
+#include "libslic3r/Format/OBJ.hpp"
+
+using namespace Slic3r;
+
+enum e_validity {
+    ASSUME_NO_EMPTY = 1,
+    ASSUME_MANIFOLD = 2,
+    ASSUME_NO_REPAIR = 4
+};
+
+void check_validity(const TriangleMesh &input_mesh,
+                    int flags = ASSUME_NO_EMPTY | ASSUME_MANIFOLD |
+                                ASSUME_NO_REPAIR);
+
+struct PadByproducts
+{
+    ExPolygons   model_contours;
+    ExPolygons   support_contours;
+    TriangleMesh mesh;
+};
+
+void test_concave_hull(const ExPolygons &polys);
+
+void test_pad(const std::string &   obj_filename,
+              const sla::PadConfig &padcfg,
+              PadByproducts &       out);
+
+inline void test_pad(const std::string &   obj_filename,
+              const sla::PadConfig &padcfg = {})
+{
+    PadByproducts byproducts;
+    test_pad(obj_filename, padcfg, byproducts);
+}
+
+struct SupportByproducts
+{
+    std::string             obj_fname;
+    std::vector<float>      slicegrid;
+    std::vector<ExPolygons> model_slices;
+    sla::SupportTreeBuilder supporttree;
+    TriangleMesh            input_mesh;
+};
+
+const constexpr float CLOSING_RADIUS = 0.005f;
+
+void check_support_tree_integrity(const sla::SupportTreeBuilder &stree,
+                                  const sla::SupportConfig &cfg);
+
+void test_supports(const std::string          &obj_filename,
+                   const sla::SupportConfig   &supportcfg,
+                   const sla::HollowingConfig &hollowingcfg,
+                   const sla::DrainHoles      &drainholes,
+                   SupportByproducts          &out);
+
+inline void test_supports(const std::string &obj_filename,
+                   const sla::SupportConfig &supportcfg,
+                   SupportByproducts        &out) 
+{
+    sla::HollowingConfig hcfg;
+    hcfg.enabled = false;
+    test_supports(obj_filename, supportcfg, hcfg, {}, out);    
+}
+
+inline void test_supports(const std::string &obj_filename,
+                   const sla::SupportConfig &supportcfg = {})
+{
+    SupportByproducts byproducts;
+    test_supports(obj_filename, supportcfg, byproducts);
+}
+
+void export_failed_case(const std::vector<ExPolygons> &support_slices,
+                        const SupportByproducts &byproducts);
+
+
+void test_support_model_collision(
+    const std::string          &obj_filename,
+    const sla::SupportConfig   &input_supportcfg,
+    const sla::HollowingConfig &hollowingcfg,
+    const sla::DrainHoles      &drainholes);
+
+inline void test_support_model_collision(
+    const std::string        &obj_filename,
+    const sla::SupportConfig &input_supportcfg = {}) 
+{
+    sla::HollowingConfig hcfg;
+    hcfg.enabled = false;
+    test_support_model_collision(obj_filename, input_supportcfg, hcfg, {});
+}
+
+#endif // SLA_TEST_UTILS_HPP

tests/test_utils.hpp

@@ -0,0 +1,21 @@
+#ifndef SLIC3R_TEST_UTILS
+#define SLIC3R_TEST_UTILS
+
+#include <libslic3r/TriangleMesh.hpp>
+#include <libslic3r/Format/OBJ.hpp>
+
+#if defined(WIN32) || defined(_WIN32)
+#define PATH_SEPARATOR R"(\)"
+#else
+#define PATH_SEPARATOR R"(/)"
+#endif
+
+inline Slic3r::TriangleMesh load_model(const std::string &obj_filename)
+{
+    Slic3r::TriangleMesh mesh;
+    auto fpath = TEST_DATA_DIR PATH_SEPARATOR + obj_filename;
+    Slic3r::load_obj(fpath.c_str(), &mesh);
+    return mesh;
+}
+
+#endif // SLIC3R_TEST_UTILS