diff --git a/src/libslic3r/BranchingTree/PointCloud.cpp b/src/libslic3r/BranchingTree/PointCloud.cpp index 319f334ff..4075a20c2 100644 --- a/src/libslic3r/BranchingTree/PointCloud.cpp +++ b/src/libslic3r/BranchingTree/PointCloud.cpp @@ -1,81 +1,15 @@ #include "PointCloud.hpp" #include "libslic3r/Tesselate.hpp" +#include "libslic3r/SLA/SupportTreeUtils.hpp" #include namespace Slic3r { namespace branchingtree { -std::optional find_merge_pt(const Vec3f &A, - const Vec3f &B, - float critical_angle) +std::optional find_merge_pt(const Vec3f &A, const Vec3f &B, float max_slope) { - // The idea is that A and B both have their support cones. But searching - // for the intersection of these support cones is difficult and its enough - // to reduce this problem to 2D and search for the intersection of two - // rays that merge somewhere between A and B. The 2D plane is a vertical - // slice of the 3D scene where the 2D Y axis is equal to the 3D Z axis and - // the 2D X axis is determined by the XY direction of the AB vector. - // - // Z^ - // | A * - // | . . B * - // | . . . . - // | . . . . - // | . x . - // -------------------> XY - - // Determine the transformation matrix for the 2D projection: - Vec3f diff = {B.x() - A.x(), B.y() - A.y(), 0.f}; - Vec3f dir = diff.normalized(); // TODO: avoid normalization - - Eigen::Matrix tr2D; - tr2D.row(0) = Vec3f{dir.x(), dir.y(), dir.z()}; - tr2D.row(1) = Vec3f{0.f, 0.f, 1.f}; - - // Transform the 2 vectors A and B into 2D vector 'a' and 'b'. Here we can - // omit 'a', pretend that its the origin and use BA as the vector b. - Vec2f b = tr2D * (B - A); - - // Get the square sine of the ray emanating from 'a' towards 'b'. This ray might - // exceed the allowed angle but that is corrected subsequently. - // The sign of the original sine is also needed, hence b.y is multiplied by - // abs(b.y) - float b_sqn = b.squaredNorm(); - float sin2sig_a = b_sqn > EPSILON ? (b.y() * std::abs(b.y())) / b_sqn : 0.f; - - // sine2 from 'b' to 'a' is the opposite of sine2 from a to b - float sin2sig_b = -sin2sig_a; - - // Derive the allowed angles from the given critical angle. - // critical_angle is measured from the horizontal X axis. - // The rays need to go downwards which corresponds to negative angles - - float sincrit = std::sin(critical_angle); // sine of the critical angle - float sin2crit = -sincrit * sincrit; // signed sine squared - sin2sig_a = std::min(sin2sig_a, sin2crit); // Do the angle saturation of both rays - sin2sig_b = std::min(sin2sig_b, sin2crit); // - float sin2_a = std::abs(sin2sig_a); // Get cosine squared values - float sin2_b = std::abs(sin2sig_b); - float cos2_a = 1.f - sin2_a; - float cos2_b = 1.f - sin2_b; - - // Derive the new direction vectors. This is by square rooting the sin2 - // and cos2 values and restoring the original signs - Vec2f Da = {std::copysign(std::sqrt(cos2_a), b.x()), std::copysign(std::sqrt(sin2_a), sin2sig_a)}; - Vec2f Db = {-std::copysign(std::sqrt(cos2_b), b.x()), std::copysign(std::sqrt(sin2_b), sin2sig_b)}; - - // Determine where two rays ([0, 0], Da), (b, Db) intersect. - // Based on - // https://stackoverflow.com/questions/27459080/given-two-points-and-two-direction-vectors-find-the-point-where-they-intersect - // One ray is emanating from (0, 0) so the formula is simplified - double t1 = (Db.y() * b.x() - b.y() * Db.x()) / - (Da.x() * Db.y() - Da.y() * Db.x()); - - Vec2f mp = t1 * Da; - Vec3f Mp = A + tr2D.transpose() * mp; - - return t1 >= 0.f ? Mp : Vec3f{}; + return sla::find_merge_pt(A, B, max_slope); } void to_eigen_mesh(const indexed_triangle_set &its, diff --git a/tests/sla_print/sla_print_tests.cpp b/tests/sla_print/sla_print_tests.cpp index d581f8340..a733e77cc 100644 --- a/tests/sla_print/sla_print_tests.cpp +++ b/tests/sla_print/sla_print_tests.cpp @@ -165,106 +165,6 @@ TEST_CASE("DefaultSupports::FloorSupportsDoNotPierceModel", "[SLASupportGenerati // for (auto &fname: SUPPORT_TEST_MODELS) test_supports(fname, supportcfg); //} -bool is_outside_support_cone(const Vec3f &supp, const Vec3f &pt, float angle) -{ - Vec3d D = (pt - supp).cast(); - double dot_sq = -D.z() * std::abs(-D.z()); - - return dot_sq < - D.squaredNorm() * std::cos(angle) * std::abs(std::cos(angle)); -} - -TEST_CASE("BranchingSupports::MergePointFinder", "[SLASupportGeneration][Branching]") { - SECTION("Identical points have the same merge point") { - Vec3f a{0.f, 0.f, 0.f}, b = a; - auto slope = float(PI / 4.); - - auto mergept = branchingtree::find_merge_pt(a, b, slope); - - REQUIRE(bool(mergept)); - REQUIRE((*mergept - b).norm() < EPSILON); - REQUIRE((*mergept - a).norm() < EPSILON); - } - - // ^ Z - // | a * - // | - // | b * <= mergept - SECTION("Points at different heights have the lower point as mergepoint") { - Vec3f a{0.f, 0.f, 0.f}, b = {0.f, 0.f, -1.f}; - auto slope = float(PI / 4.); - - auto mergept = branchingtree::find_merge_pt(a, b, slope); - - REQUIRE(bool(mergept)); - REQUIRE((*mergept - b).squaredNorm() < 2 * EPSILON); - } - - // -|---------> X - // a b - // * * - // * <= mergept - SECTION("Points at different X have mergept in the middle at lower Z") { - Vec3f a{0.f, 0.f, 0.f}, b = {1.f, 0.f, 0.f}; - auto slope = float(PI / 4.); - - auto mergept = branchingtree::find_merge_pt(a, b, slope); - - REQUIRE(bool(mergept)); - - // Distance of mergept should be equal from both input points - float D = std::abs((*mergept - b).squaredNorm() - (*mergept - a).squaredNorm()); - - REQUIRE(D < EPSILON); - REQUIRE(!is_outside_support_cone(a, *mergept, slope)); - REQUIRE(!is_outside_support_cone(b, *mergept, slope)); - } - - // -|---------> Y - // a b - // * * - // * <= mergept - SECTION("Points at different Y have mergept in the middle at lower Z") { - Vec3f a{0.f, 0.f, 0.f}, b = {0.f, 1.f, 0.f}; - auto slope = float(PI / 4.); - - auto mergept = branchingtree::find_merge_pt(a, b, slope); - - REQUIRE(bool(mergept)); - - // Distance of mergept should be equal from both input points - float D = std::abs((*mergept - b).squaredNorm() - (*mergept - a).squaredNorm()); - - REQUIRE(D < EPSILON); - REQUIRE(!is_outside_support_cone(a, *mergept, slope)); - REQUIRE(!is_outside_support_cone(b, *mergept, slope)); - } - - SECTION("Points separated by less than critical angle have the lower point as mergept") { - Vec3f a{-1.f, -1.f, -1.f}, b = {-1.5f, -1.5f, -2.f}; - auto slope = float(PI / 4.); - - auto mergept = branchingtree::find_merge_pt(a, b, slope); - - REQUIRE(bool(mergept)); - REQUIRE((*mergept - b).norm() < 2 * EPSILON); - } - - // -|----------------------------> Y - // a b - // * * <= mergept * - // - SECTION("Points at same height have mergepoint in the middle if critical angle is zero ") { - Vec3f a{-1.f, -1.f, -1.f}, b = {-1.5f, -1.5f, -1.f}; - auto slope = EPSILON; - - auto mergept = branchingtree::find_merge_pt(a, b, slope); - - REQUIRE(bool(mergept)); - Vec3f middle = (b + a) / 2.; - REQUIRE((*mergept - middle).norm() < 4 * EPSILON); - } -} TEST_CASE("BranchingSupports::ElevatedSupportsDoNotPierceModel", "[SLASupportGeneration][Branching]") { diff --git a/tests/sla_print/sla_supptreeutils_tests.cpp b/tests/sla_print/sla_supptreeutils_tests.cpp index 69117358d..d529eefb5 100644 --- a/tests/sla_print/sla_supptreeutils_tests.cpp +++ b/tests/sla_print/sla_supptreeutils_tests.cpp @@ -262,3 +262,98 @@ TEST_CASE("Avoid disk below junction with barrier on the side", "[suptreeutils]" REQUIRE(pR + FromRadius > CylRadius); } } + +TEST_CASE("BranchingSupports::MergePointFinder", "[suptreeutils]") { + using namespace Slic3r; + + SECTION("Identical points have the same merge point") { + Vec3f a{0.f, 0.f, 0.f}, b = a; + auto slope = float(PI / 4.); + + auto mergept = sla::find_merge_pt(a, b, slope); + + REQUIRE(bool(mergept)); + REQUIRE((*mergept - b).norm() < EPSILON); + REQUIRE((*mergept - a).norm() < EPSILON); + } + + // ^ Z + // | a * + // | + // | b * <= mergept + SECTION("Points at different heights have the lower point as mergepoint") { + Vec3f a{0.f, 0.f, 0.f}, b = {0.f, 0.f, -1.f}; + auto slope = float(PI / 4.); + + auto mergept = sla::find_merge_pt(a, b, slope); + + REQUIRE(bool(mergept)); + REQUIRE((*mergept - b).squaredNorm() < 2 * EPSILON); + } + + // -|---------> X + // a b + // * * + // * <= mergept + SECTION("Points at different X have mergept in the middle at lower Z") { + Vec3f a{0.f, 0.f, 0.f}, b = {1.f, 0.f, 0.f}; + auto slope = float(PI / 4.); + + auto mergept = sla::find_merge_pt(a, b, slope); + + REQUIRE(bool(mergept)); + + // Distance of mergept should be equal from both input points + float D = std::abs((*mergept - b).squaredNorm() - (*mergept - a).squaredNorm()); + + REQUIRE(D < EPSILON); + REQUIRE(!sla::is_outside_support_cone(a, *mergept, slope)); + REQUIRE(!sla::is_outside_support_cone(b, *mergept, slope)); + } + + // -|---------> Y + // a b + // * * + // * <= mergept + SECTION("Points at different Y have mergept in the middle at lower Z") { + Vec3f a{0.f, 0.f, 0.f}, b = {0.f, 1.f, 0.f}; + auto slope = float(PI / 4.); + + auto mergept = sla::find_merge_pt(a, b, slope); + + REQUIRE(bool(mergept)); + + // Distance of mergept should be equal from both input points + float D = std::abs((*mergept - b).squaredNorm() - (*mergept - a).squaredNorm()); + + REQUIRE(D < EPSILON); + REQUIRE(!sla::is_outside_support_cone(a, *mergept, slope)); + REQUIRE(!sla::is_outside_support_cone(b, *mergept, slope)); + } + + SECTION("Points separated by less than critical angle have the lower point as mergept") { + Vec3f a{-1.f, -1.f, -1.f}, b = {-1.5f, -1.5f, -2.f}; + auto slope = float(PI / 4.); + + auto mergept = sla::find_merge_pt(a, b, slope); + + REQUIRE(bool(mergept)); + REQUIRE((*mergept - b).norm() < 2 * EPSILON); + } + + // -|----------------------------> Y + // a b + // * * <= mergept * + // + SECTION("Points at same height have mergepoint in the middle if critical angle is zero ") { + Vec3f a{-1.f, -1.f, -1.f}, b = {-1.5f, -1.5f, -1.f}; + auto slope = EPSILON; + + auto mergept = sla::find_merge_pt(a, b, slope); + + REQUIRE(bool(mergept)); + Vec3f middle = (b + a) / 2.; + REQUIRE((*mergept - middle).norm() < 4 * EPSILON); + } +} +