From 3aadd6e0808e7aed0011f45d4c04b3230f4ef1d7 Mon Sep 17 00:00:00 2001
From: Noisyfox <timemanager.rick@gmail.com>
Date: Sat, 9 May 2026 21:48:52 +0800
Subject: [PATCH] Remap paint after mesh boolean

---
 src/slic3r/GUI/Gizmos/GLGizmoMeshBoolean.cpp | 32 +++++++++++++++++---
 src/slic3r/GUI/Gizmos/GLGizmoMeshBoolean.hpp |  4 ++-
 2 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/src/slic3r/GUI/Gizmos/GLGizmoMeshBoolean.cpp b/src/slic3r/GUI/Gizmos/GLGizmoMeshBoolean.cpp
index bfff70d315..c7186e5d80 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoMeshBoolean.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoMeshBoolean.cpp
@@ -188,6 +188,19 @@ CommonGizmosDataID GLGizmoMeshBoolean::on_get_requirements() const
         | int(CommonGizmosDataID::ObjectClipper));
 }
 
+std::optional<TriangleSelector::SavedPainting> VolumeInfo::save_painting() const
+{
+    if (wxGetApp().app_config->get_bool("keep_painting")) {
+        std::optional<TriangleSelector::SavedPainting> saved_painting = mv->save_painting();
+        if (saved_painting) {
+            saved_painting->mesh.transform(trafo);
+        }
+        return saved_painting;
+    }
+
+    return {};
+}
+
 void GLGizmoMeshBoolean::on_render_input_window(float x, float y, float bottom_limit)
 {
     y = std::min(y, bottom_limit - ImGui::GetWindowHeight());
@@ -346,7 +359,9 @@ void GLGizmoMeshBoolean::on_render_input_window(float x, float y, float bottom_l
             std::vector<TriangleMesh> temp_mesh_resuls;
             Slic3r::MeshBoolean::mcut::make_boolean(temp_src_mesh, temp_tool_mesh, temp_mesh_resuls, "UNION");
             if (temp_mesh_resuls.size() != 0) {
-                generate_new_volume(true, *temp_mesh_resuls.begin());
+                // For union, we want to keep paint from both meshes
+                std::vector<std::optional<TriangleSelector::SavedPainting>> saved_paintings{m_src.save_painting(), m_tool.save_painting()};
+                generate_new_volume(true, *temp_mesh_resuls.begin(), saved_paintings);
                 wxGetApp().notification_manager()->close_plater_warning_notification(warning_text);
             }
             else {
@@ -364,7 +379,9 @@ void GLGizmoMeshBoolean::on_render_input_window(float x, float y, float bottom_l
             std::vector<TriangleMesh> temp_mesh_resuls;
             Slic3r::MeshBoolean::mcut::make_boolean(temp_src_mesh, temp_tool_mesh, temp_mesh_resuls, "A_NOT_B");
             if (temp_mesh_resuls.size() != 0) {
-                generate_new_volume(m_diff_delete_input, *temp_mesh_resuls.begin());
+                // For diff, we only need paint from src
+                std::vector<std::optional<TriangleSelector::SavedPainting>> saved_paintings{m_src.save_painting()};
+                generate_new_volume(m_diff_delete_input, *temp_mesh_resuls.begin(), saved_paintings);
                 wxGetApp().notification_manager()->close_plater_warning_notification(warning_text);
             }
             else {
@@ -382,7 +399,9 @@ void GLGizmoMeshBoolean::on_render_input_window(float x, float y, float bottom_l
             std::vector<TriangleMesh> temp_mesh_resuls;
             Slic3r::MeshBoolean::mcut::make_boolean(temp_src_mesh, temp_tool_mesh, temp_mesh_resuls, "INTERSECTION");
             if (temp_mesh_resuls.size() != 0) {
-                generate_new_volume(m_inter_delete_input, *temp_mesh_resuls.begin());
+                // For intersection, we want to keep paint from both meshes
+                std::vector<std::optional<TriangleSelector::SavedPainting>> saved_paintings{m_src.save_painting(), m_tool.save_painting()};
+                generate_new_volume(m_inter_delete_input, *temp_mesh_resuls.begin(), saved_paintings);
                 wxGetApp().notification_manager()->close_plater_warning_notification(warning_text);
             }
             else {
@@ -420,7 +439,7 @@ void GLGizmoMeshBoolean::on_save(cereal::BinaryOutputArchive &ar) const
     ar(m_enable, m_operation_mode, m_selecting_state, m_diff_delete_input, m_inter_delete_input, m_src, m_tool);
 }
 
-void GLGizmoMeshBoolean::generate_new_volume(bool delete_input, const TriangleMesh& mesh_result) {
+void GLGizmoMeshBoolean::generate_new_volume(const bool delete_input, TriangleMesh& mesh_result, const std::vector<std::optional<TriangleSelector::SavedPainting>>& saved_paintings) {
 
     wxGetApp().plater()->take_snapshot("Mesh Boolean");
 
@@ -429,6 +448,11 @@ void GLGizmoMeshBoolean::generate_new_volume(bool delete_input, const TriangleMe
     // generate new volume
     ModelVolume* new_volume = curr_model_object->add_volume(std::move(mesh_result));
 
+    // Remap paintings
+    for (const auto& saved_painting : saved_paintings) {
+        new_volume->restore_painting(saved_painting, true);
+    }
+
     // assign to new_volume from old_volume
     ModelVolume* old_volume = m_src.mv;
     std::string suffix;
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoMeshBoolean.hpp b/src/slic3r/GUI/Gizmos/GLGizmoMeshBoolean.hpp
index c012a68dca..9c36be5cd9 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoMeshBoolean.hpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoMeshBoolean.hpp
@@ -34,6 +34,8 @@ struct VolumeInfo {
     void serialize(Archive& ar) {
         ar(volume_idx, trafo);
     }
+
+    std::optional<TriangleSelector::SavedPainting> save_painting() const;
 };
 class GLGizmoMeshBoolean : public GLGizmoBase
 {
@@ -87,7 +89,7 @@ private:
     VolumeInfo m_src;
     VolumeInfo m_tool;
 
-    void generate_new_volume(bool delete_input, const TriangleMesh& mesh_result);
+    void generate_new_volume(bool delete_input, TriangleMesh& mesh_result, const std::vector<std::optional<TriangleSelector::SavedPainting>>& saved_paintings);
 };
 
 } // namespace GUI