Create smaller supports in problematic areas with established strategies

Completely remove the concept of CompactBridge.

Replace it with Heads having the same back radius as front radius. 

Try to apply the same rules for mini supports as in the route_to_model step.

Increased accuracy of bridge_mesh_intersect shot from support points


Refining mini support integration

tests/sla_print/CMakeLists.txt

@@ -1,7 +1,7 @@
 get_filename_component(_TEST_NAME ${CMAKE_CURRENT_LIST_DIR} NAME)
 add_executable(${_TEST_NAME}_tests ${_TEST_NAME}_tests_main.cpp 
     sla_print_tests.cpp 
-    sla_test_utils.hpp sla_test_utils.cpp
+    sla_test_utils.hpp sla_test_utils.cpp sla_treebuilder_tests.cpp
     sla_raycast_tests.cpp)
 target_link_libraries(${_TEST_NAME}_tests test_common libslic3r)
 set_property(TARGET ${_TEST_NAME}_tests PROPERTY FOLDER "tests")

tests/sla_print/sla_test_utils.cpp

@@ -129,8 +129,7 @@ void test_supports(const std::string          &obj_filename,
     // 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);
+        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());
@@ -141,7 +140,8 @@ void test_supports(const std::string          &obj_filename,
     
     // Generate the actual support tree
     sla::SupportTreeBuilder treebuilder;
-    treebuilder.build(sla::SupportableMesh{emesh, support_points, supportcfg});
+    sla::SupportableMesh    sm{emesh, support_points, supportcfg};
+    sla::SupportTreeBuildsteps::execute(treebuilder, sm);
     
     check_support_tree_integrity(treebuilder, supportcfg);
     

tests/sla_print/sla_treebuilder_tests.cpp

@@ -0,0 +1,96 @@
+#include <catch2/catch.hpp>
+#include <test_utils.hpp>
+
+#include "libslic3r/TriangleMesh.hpp"
+#include "libslic3r/SLA/SupportTreeBuilder.hpp"
+
+TEST_CASE("Test bridge_mesh_intersect on a cube's wall", "[SLABridgeMeshInters]") {
+    using namespace Slic3r;
+
+    TriangleMesh cube = make_cube(10., 10., 10.);
+
+    sla::SupportConfig cfg = {}; // use default config
+    sla::SupportPoints pts = {{10.f, 5.f, 5.f, float(cfg.head_front_radius_mm), false}};
+    sla::SupportableMesh sm{cube, pts, cfg};
+
+    SECTION("Bridge is straight horizontal and pointing away from the cube") {
+
+        sla::Bridge bridge(pts[0].pos.cast<double>(), Vec3d{15., 5., 5.},
+                           pts[0].head_front_radius);
+
+        auto hit = sla::query_hit(sm, bridge);
+
+        REQUIRE(std::isinf(hit.distance()));
+
+        cube.merge(sla::to_triangle_mesh(bridge.mesh));
+        cube.require_shared_vertices();
+        cube.WriteOBJFile("cube1.obj");
+    }
+
+    SECTION("Bridge is tilted down in 45 degrees, pointing away from the cube") {
+        sla::Bridge bridge(pts[0].pos.cast<double>(), Vec3d{15., 5., 0.},
+                           pts[0].head_front_radius);
+
+        auto hit = sla::query_hit(sm, bridge);
+
+        REQUIRE(std::isinf(hit.distance()));
+
+        cube.merge(sla::to_triangle_mesh(bridge.mesh));
+        cube.require_shared_vertices();
+        cube.WriteOBJFile("cube2.obj");
+    }
+}
+
+
+TEST_CASE("Test bridge_mesh_intersect on a sphere", "[SLABridgeMeshInters]") {
+    using namespace Slic3r;
+
+    TriangleMesh sphere = make_sphere(1.);
+
+    sla::SupportConfig cfg = {}; // use default config
+    cfg.head_back_radius_mm = cfg.head_front_radius_mm;
+    sla::SupportPoints pts = {{1.f, 0.f, 0.f, float(cfg.head_front_radius_mm), false}};
+    sla::SupportableMesh sm{sphere, pts, cfg};
+
+    SECTION("Bridge is straight horizontal and pointing away from the sphere") {
+
+        sla::Bridge bridge(pts[0].pos.cast<double>(), Vec3d{2., 0., 0.},
+                           pts[0].head_front_radius);
+
+        auto hit = sla::query_hit(sm, bridge);
+
+        sphere.merge(sla::to_triangle_mesh(bridge.mesh));
+        sphere.require_shared_vertices();
+        sphere.WriteOBJFile("sphere1.obj");
+
+        REQUIRE(std::isinf(hit.distance()));
+    }
+
+    SECTION("Bridge is tilted down 45 deg and pointing away from the sphere") {
+
+        sla::Bridge bridge(pts[0].pos.cast<double>(), Vec3d{2., 0., -2.},
+                           pts[0].head_front_radius);
+
+        auto hit = sla::query_hit(sm, bridge);
+
+        sphere.merge(sla::to_triangle_mesh(bridge.mesh));
+        sphere.require_shared_vertices();
+        sphere.WriteOBJFile("sphere2.obj");
+
+        REQUIRE(std::isinf(hit.distance()));
+    }
+
+    SECTION("Bridge is tilted down 90 deg and pointing away from the sphere") {
+
+        sla::Bridge bridge(pts[0].pos.cast<double>(), Vec3d{1., 0., -2.},
+                           pts[0].head_front_radius);
+
+        auto hit = sla::query_hit(sm, bridge);
+
+        sphere.merge(sla::to_triangle_mesh(bridge.mesh));
+        sphere.require_shared_vertices();
+        sphere.WriteOBJFile("sphere3.obj");
+
+        REQUIRE(std::isinf(hit.distance()));
+    }
+}