From 4e64e7e74fa90eed0c40bd3432f2696b804dfb19 Mon Sep 17 00:00:00 2001
From: tamasmeszaros <meszaros.q@gmail.com>
Date: Tue, 28 Feb 2023 11:06:19 +0100
Subject: [PATCH] Export boolean-ed models if possible to STL/obj files

---
 src/slic3r/GUI/Plater.cpp | 38 +++++++++++++++++++++++++++++++-------
 1 file changed, 31 insertions(+), 7 deletions(-)

diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 3595276af..6fb7521c4 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -54,6 +54,10 @@
 #include "libslic3r/ClipperUtils.hpp"
 #include "libslic3r/miniz_extension.hpp"
 
+// For stl export
+#include "libslic3r/CSGMesh/ModelToCSGMesh.hpp"
+#include "libslic3r/CSGMesh/PerformCSGMeshBooleans.hpp"
+
 #include "GUI.hpp"
 #include "GUI_App.hpp"
 #include "GUI_ObjectList.hpp"
@@ -6382,14 +6386,34 @@ void Plater::export_stl_obj(bool extended, bool selection_only)
         return;
 
     // Following lambda generates a combined mesh for export with normals pointing outwards.
-    auto mesh_to_export_fff = [](const ModelObject& mo, int instance_id) {
+    auto mesh_to_export_fff = [this](const ModelObject& mo, int instance_id) {
         TriangleMesh mesh;
-        for (const ModelVolume* v : mo.volumes)
-            if (v->is_model_part()) {
-                TriangleMesh vol_mesh(v->mesh());
-                vol_mesh.transform(v->get_matrix(), true);
-                mesh.merge(vol_mesh);
-            }
+
+        std::vector<csg::CSGPart> csgmesh;
+        csgmesh.reserve(2 * mo.volumes.size());
+        csg::model_to_csgmesh(mo, Transform3d::Identity(), std::back_inserter(csgmesh),
+                              csg::mpartsPositive | csg::mpartsNegative | csg::mpartsDoSplits);
+
+        if (csg::check_csgmesh_booleans(range(csgmesh)) == csgmesh.end()) {
+            try {
+                auto cgalm = csg::perform_csgmesh_booleans(range(csgmesh));
+                mesh = MeshBoolean::cgal::cgal_to_triangle_mesh(*cgalm);
+            } catch (...) {}
+        }
+
+        if (mesh.empty()) {
+            get_notification_manager()->push_plater_warning_notification(
+                _u8L("Unable to perform boolean operation on model meshes. "
+                     "Only positive parts will be exported."));
+
+            for (const ModelVolume* v : mo.volumes)
+                if (v->is_model_part()) {
+                    TriangleMesh vol_mesh(v->mesh());
+                    vol_mesh.transform(v->get_matrix(), true);
+                    mesh.merge(vol_mesh);
+                }
+        }
+
         if (instance_id == -1) {
             TriangleMesh vols_mesh(mesh);
             mesh = TriangleMesh();