Added unit test for checking geometry after save+load to 3mf cycle

src/libslic3r/Format/3mf.cpp

@@ -716,8 +716,8 @@ namespace Slic3r {
                 return false;
         }
 
-        // fixes the min z of the model if negative
+//        // fixes the min z of the model if negative
-        model.adjust_min_z();
+//        model.adjust_min_z();
 
         return true;
     }

tests/libslic3r/test_3mf.cpp

@@ -2,19 +2,86 @@
 
 #include "libslic3r/Model.hpp"
 #include "libslic3r/Format/3mf.hpp"
+#include "libslic3r/Format/stl.hpp"
+
+#include <boost/filesystem/operations.hpp>
 
 using namespace Slic3r;
 
 SCENARIO("Reading 3mf file", "[3mf]") {
     GIVEN("umlauts in the path of the file") {
-        Slic3r::Model model;
+        Model model;
         WHEN("3mf model is read") {
         	std::string path = std::string(TEST_DATA_DIR) + "/test_3mf/Geräte/Büchse.3mf";
         	DynamicPrintConfig config;
-            bool ret = Slic3r::load_3mf(path.c_str(), &config, &model, false);
+            bool ret = load_3mf(path.c_str(), &config, &model, false);
             THEN("load should succeed") {
                 REQUIRE(ret);
             }
         }
     }
 }
+
+SCENARIO("Export+Import geometry to/from 3mf file cycle", "[3mf]") {
+    GIVEN("world vertices coordinates before save") {
+        // load a model from stl file
+        Model src_model;
+        std::string src_file = std::string(TEST_DATA_DIR) + "/test_3mf/prusa.stl";
+        load_stl(src_file.c_str(), &src_model);
+        src_model.add_default_instances();
+
+        ModelObject* src_object = src_model.objects[0];
+
+        // apply generic transformation to the 1st volume
+        Geometry::Transformation src_volume_transform;
+        src_volume_transform.set_offset(Vec3d(10.0, 20.0, 0.0));
+        src_volume_transform.set_rotation(Vec3d(Geometry::deg2rad(25.0), Geometry::deg2rad(35.0), Geometry::deg2rad(45.0)));
+        src_volume_transform.set_scaling_factor(Vec3d(1.1, 1.2, 1.3));
+        src_volume_transform.set_mirror(Vec3d(-1.0, 1.0, -1.0));
+        src_object->volumes[0]->set_transformation(src_volume_transform);
+
+        // apply generic transformation to the 1st instance
+        Geometry::Transformation src_instance_transform;
+        src_instance_transform.set_offset(Vec3d(5.0, 10.0, 0.0));
+        src_instance_transform.set_rotation(Vec3d(Geometry::deg2rad(12.0), Geometry::deg2rad(13.0), Geometry::deg2rad(14.0)));
+        src_instance_transform.set_scaling_factor(Vec3d(0.9, 0.8, 0.7));
+        src_instance_transform.set_mirror(Vec3d(1.0, -1.0, -1.0));
+        src_object->instances[0]->set_transformation(src_instance_transform);
+
+        WHEN("model is saved+loaded to/from 3mf file") {
+            // save the model to 3mf file
+            std::string test_file = std::string(TEST_DATA_DIR) + "/test_3mf/prusa.3mf";
+            store_3mf(test_file.c_str(), &src_model, nullptr);
+
+            // load back the model from the 3mf file
+            Model dst_model;
+            DynamicPrintConfig dst_config;
+            load_3mf(test_file.c_str(), &dst_config, &dst_model, false);
+            boost::filesystem::remove(test_file);
+
+            // compare meshes
+            TriangleMesh src_mesh = src_model.mesh();
+            src_mesh.repair();
+
+            TriangleMesh dst_mesh = dst_model.mesh();
+            dst_mesh.repair();
+
+            bool res = src_mesh.its.vertices.size() == dst_mesh.its.vertices.size();
+            if (res)
+            {
+                for (size_t i = 0; i < dst_mesh.its.vertices.size(); ++i)
+                {
+                    res &= dst_mesh.its.vertices[i].isApprox(src_mesh.its.vertices[i]);
+                    if (!res)
+                    {
+                        Vec3f diff = dst_mesh.its.vertices[i] - src_mesh.its.vertices[i];
+                        std::cout << i << ": diff " << to_string((Vec3d)diff.cast<double>()) << "\n";
+                    }
+                }
+            }
+            THEN("world vertices coordinates after load match") {
+                REQUIRE(res);
+            }
+        }
+    }
+}