diff --git a/src/pstack/calc/stacker.cpp b/src/pstack/calc/stacker.cpp
index 0ab0778..916da4f 100644
--- a/src/pstack/calc/stacker.cpp
+++ b/src/pstack/calc/stacker.cpp
@@ -24,6 +24,8 @@ struct stack_state {
     util::mdarray<Bool, 3> space;
     std::vector<std::shared_ptr<const part>> ordered_parts;
     stack_result result;
+    std::size_t total_parts;
+    std::size_t total_placed;
 };
 
 void place(const util::mdspan<Bool, 3> space, const int index, const util::mdspan<const int, 3> obj, const int x, const int y, const int z) {
@@ -100,6 +102,9 @@ std::size_t try_place(const stack_parameters& params, stack_state& state, const
                             new_piece.translation += translation;
                             place(state.space, bit_index, state.voxels[part_index], x, y, z); // Mark voxels as occupied
                             ++placed;
+                            ++state.total_placed;
+                            params.set_progress(state.total_placed, state.total_parts);
+                            params.display_mesh(state.result.mesh, max);
                             if (to_place == placed) { // All instances of this part placed, move to next part
                                 return placed;
                             } else { // Move to next instance of part
@@ -125,10 +130,11 @@ std::optional<stack_result> stack_impl(const stack_parameters& params, const std
 
     double triangles = 0;
     const double scale_factor = 1 / params.resolution;
-    int total_parts = 0;
+    state.total_parts = 0;
+    state.total_placed = 0;
     for (const std::shared_ptr<const part> part : state.ordered_parts) {
         triangles += part->triangle_count * rotation_sets[part->rotation_index].size();
-        total_parts += part->quantity;
+        state.total_parts += part->quantity;
     }
 
     double progress = 0;
@@ -232,7 +238,6 @@ std::optional<stack_result> stack_impl(const stack_parameters& params, const std
 
     params.set_progress(0, 1);
 
-    std::size_t total_placed = 0;
     for (std::size_t part_index = 0; part_index != state.ordered_parts.size(); ++part_index) {
         std::size_t to_place = state.ordered_parts[part_index]->quantity;
         while (to_place > 0) {
@@ -241,9 +246,6 @@ std::optional<stack_result> stack_impl(const stack_parameters& params, const std
             }
             const std::size_t placed = try_place(params, state, part_index, to_place, { max_x, max_y, max_z });
             to_place -= placed;
-            total_placed += placed;
-            params.set_progress(total_placed, total_parts);
-            params.display_mesh(state.result.mesh, max_x, max_y, max_z);
 
             // If we have not placed a part, it means there are no more ways to place an instance of the current part in the box: it must be enlarged
             if (placed == 0) {
diff --git a/src/pstack/calc/stacker.hpp b/src/pstack/calc/stacker.hpp
index d24fc74..f9874f4 100644
--- a/src/pstack/calc/stacker.hpp
+++ b/src/pstack/calc/stacker.hpp
@@ -30,7 +30,7 @@ struct stack_parameters {
     std::vector<std::shared_ptr<const part>> parts;
 
     std::function<void(double, double)> set_progress;
-    std::function<void(const mesh&, int, int, int)> display_mesh;
+    std::function<void(const mesh&, const geo::point3<int>)> display_mesh;
     std::function<void(stack_result, std::chrono::system_clock::duration)> on_success;
     std::function<void()> on_failure;
     std::function<void()> on_finish;
diff --git a/src/pstack/gui/main_window.cpp b/src/pstack/gui/main_window.cpp
index a5c02d5..e18ad3a 100644
--- a/src/pstack/gui/main_window.cpp
+++ b/src/pstack/gui/main_window.cpp
@@ -190,10 +190,10 @@ void main_window::on_stacking_start() {
                 _controls.progress_bar->SetValue(static_cast<int>(100 * progress / total));
             });
         },
-        .display_mesh = [this](const calc::mesh& mesh, int max_x, int max_y, int max_z) {
+        .display_mesh = [this](const calc::mesh& mesh, const geo::point3<int> max) {
             CallAfter([=] {
                 // Make a copy of `mesh`, otherwise we encounter a data race
-                _viewport->set_mesh(mesh, { max_x / 2.0f, max_y / 2.0f, max_z / 2.0f });
+                _viewport->set_mesh(mesh, { max.x / 2.0f, max.y / 2.0f, max.z / 2.0f });
             });
         },
         .on_success = [this](calc::stack_result result, const std::chrono::system_clock::duration elapsed) {