diff --git a/lib/Slic3r/Print/Object.pm b/lib/Slic3r/Print/Object.pm
index 78ff619cb..168f78bb3 100644
--- a/lib/Slic3r/Print/Object.pm
+++ b/lib/Slic3r/Print/Object.pm
@@ -335,39 +335,6 @@ sub slice {
     $self->set_step_done(STEP_SLICE);
 }
 
-# called from slice()
-sub _slice_region {
-    my ($self, $region_id, $z, $modifier) = @_;
-
-    return [] if !@{$self->get_region_volumes($region_id)};
-
-    # compose mesh
-    my $mesh;
-    foreach my $volume_id (@{ $self->get_region_volumes($region_id) }) {
-        my $volume = $self->model_object->volumes->[$volume_id];
-        next if $volume->modifier && !$modifier;
-        next if !$volume->modifier && $modifier;
-        
-        if (defined $mesh) {
-            $mesh->merge($volume->mesh);
-        } else {
-            $mesh = $volume->mesh->clone;
-        }
-    }
-    return if !defined $mesh;
-
-    # transform mesh
-    # we ignore the per-instance transformations currently and only 
-    # consider the first one
-    $self->model_object->instances->[0]->transform_mesh($mesh, 1);
-
-    # align mesh to Z = 0 (it should be already aligned actually) and apply XY shift
-    $mesh->translate((map unscale(-$_), @{$self->_copies_shift}), -$self->model_object->bounding_box->z_min);
-    
-    # perform actual slicing
-    return $mesh->slice($z);
-}
-
 sub make_perimeters {
     my ($self) = @_;
     
diff --git a/xs/src/libslic3r/Print.hpp b/xs/src/libslic3r/Print.hpp
index 4b586a2f4..65f61f3fb 100644
--- a/xs/src/libslic3r/Print.hpp
+++ b/xs/src/libslic3r/Print.hpp
@@ -100,7 +100,7 @@ class PrintObject
     PrintState<PrintObjectStep> state;
     
     Print* print();
-    ModelObject* model_object();
+    ModelObject* model_object() { return this->_model_object; };
     
     Points copies() const;
     bool add_copy(const Pointf &point);
@@ -136,6 +136,7 @@ class PrintObject
     void detect_surfaces_type();
     void process_external_surfaces();
     void bridge_over_infill();
+    std::vector<ExPolygons> _slice_region(size_t region_id, std::vector<float> z, bool modifier);
     void _make_perimeters();
     void _infill();
     
diff --git a/xs/src/libslic3r/PrintObject.cpp b/xs/src/libslic3r/PrintObject.cpp
index 90752461e..97263036d 100644
--- a/xs/src/libslic3r/PrintObject.cpp
+++ b/xs/src/libslic3r/PrintObject.cpp
@@ -40,12 +40,6 @@ PrintObject::print()
     return this->_print;
 }
 
-ModelObject*
-PrintObject::model_object()
-{
-    return this->_model_object;
-}
-
 Points
 PrintObject::copies() const
 {
@@ -665,6 +659,45 @@ PrintObject::bridge_over_infill()
     }
 }
 
+// called from slice()
+std::vector<ExPolygons>
+PrintObject::_slice_region(size_t region_id, std::vector<float> z, bool modifier)
+{
+    std::vector<ExPolygons> layers;
+    std::vector<int> &region_volumes = this->region_volumes[region_id];
+    if (region_volumes.empty()) return layers;
+    
+    ModelObject &object = *this->model_object();
+    
+    // compose mesh
+    TriangleMesh mesh;
+    for (std::vector<int>::const_iterator it = region_volumes.begin();
+        it != region_volumes.end(); ++it) {
+        
+        const ModelVolume &volume = *object.volumes[*it];
+        if (volume.modifier != modifier) continue;
+        
+        mesh.merge(volume.mesh);
+    }
+    if (mesh.facets_count() == 0) return layers;
+
+    // transform mesh
+    // we ignore the per-instance transformations currently and only 
+    // consider the first one
+    object.instances[0]->transform_mesh(&mesh, true);
+
+    // align mesh to Z = 0 (it should be already aligned actually) and apply XY shift
+    mesh.translate(
+        unscale(this->_copies_shift.x),
+        unscale(this->_copies_shift.y),
+        -object.bounding_box().min.z
+    );
+    
+    // perform actual slicing
+    TriangleMeshSlicer<Z>(&mesh).slice(z, &layers);
+    return layers;
+}
+
 void
 PrintObject::_make_perimeters()
 {
diff --git a/xs/xsp/Print.xsp b/xs/xsp/Print.xsp
index 9da32d674..0cd8e01f4 100644
--- a/xs/xsp/Print.xsp
+++ b/xs/xsp/Print.xsp
@@ -110,6 +110,25 @@ _constant()
     void detect_surfaces_type();
     void process_external_surfaces();
     void bridge_over_infill();
+    SV* _slice_region(size_t region_id, std::vector<double> z, bool modifier)
+        %code%{
+            std::vector<float> z_f(z.begin(), z.end());
+            std::vector<ExPolygons> layers = THIS->_slice_region(region_id, z_f, modifier);
+            AV* layers_av = newAV();
+            size_t len = layers.size();
+            if (len > 0) av_extend(layers_av, len-1);
+            for (unsigned int i = 0; i < layers.size(); i++) {
+                AV* expolygons_av = newAV();
+                len = layers[i].size();
+                if (len > 0) av_extend(expolygons_av, len-1);
+                unsigned int j = 0;
+                for (ExPolygons::iterator it = layers[i].begin(); it != layers[i].end(); ++it) {
+                    av_store(expolygons_av, j++, perl_to_SV_clone_ref(*it));
+                }
+                av_store(layers_av, i, newRV_noinc((SV*)expolygons_av));
+            }
+            RETVAL = (SV*)newRV_noinc((SV*)layers_av);
+        %};
     void _make_perimeters();
     void _infill();