diff --git a/lib/Slic3r/Model.pm b/lib/Slic3r/Model.pm
index bdb528d59..5f9a808b6 100644
--- a/lib/Slic3r/Model.pm
+++ b/lib/Slic3r/Model.pm
@@ -384,14 +384,6 @@ sub add_instance {
     }
 }
 
-sub raw_mesh {
-    my $self = shift;
-    
-    my $mesh = Slic3r::TriangleMesh->new;
-    $mesh->merge($_->mesh) for grep !$_->modifier, @{ $self->volumes };
-    return $mesh;
-}
-
 sub raw_bounding_box {
     my $self = shift;
     
@@ -635,32 +627,4 @@ sub cut {
     return ($model, $upper, $lower);
 }
 
-package Slic3r::Model::Volume;
-
-sub assign_unique_material {
-    my ($self) = @_;
-    
-    my $model = $self->object->model;
-    my $material_id = 1 + $model->material_count;
-    $self->material_id($material_id);
-    return $model->set_material($material_id);
-}
-
-package Slic3r::Model::Instance;
-
-sub transform_mesh {
-    my ($self, $mesh, $dont_translate) = @_;
-    
-    $mesh->rotate($self->rotation, Slic3r::Point->new(0,0));   # rotate around mesh origin
-    $mesh->scale($self->scaling_factor);                       # scale around mesh origin
-    $mesh->translate(@{$self->offset}, 0) unless $dont_translate;
-}
-
-sub transform_polygon {
-    my ($self, $polygon) = @_;
-    
-    $polygon->rotate($self->rotation, Slic3r::Point->new(0,0));   # rotate around origin
-    $polygon->scale($self->scaling_factor);                       # scale around origin
-}
-
 1;
diff --git a/xs/src/libslic3r/Model.cpp b/xs/src/libslic3r/Model.cpp
index ee8dc1057..cf7d9d1c5 100644
--- a/xs/src/libslic3r/Model.cpp
+++ b/xs/src/libslic3r/Model.cpp
@@ -312,6 +312,15 @@ ModelObject::invalidate_bounding_box()
     this->_bounding_box_valid = false;
 }
 
+void
+ModelObject::raw_mesh(TriangleMesh* mesh) const
+{
+    for (ModelVolumePtrs::const_iterator v = this->volumes.begin(); v != this->volumes.end(); ++v) {
+        if ((*v)->modifier) continue;
+        mesh->merge((*v)->mesh);
+    }
+}
+
 #ifdef SLIC3RXS
 REGISTER_CLASS(ModelObject, "Model::Object");
 #endif
@@ -349,6 +358,15 @@ ModelVolume::material() const
     return this->object->get_model()->get_material(this->_material_id);
 }
 
+ModelMaterial*
+ModelVolume::assign_unique_material()
+{
+    Model* model = this->get_object()->get_model();
+    
+    this->_material_id = 1 + model->materials.size();
+    return model->add_material(this->_material_id);
+}
+
 #ifdef SLIC3RXS
 REGISTER_CLASS(ModelVolume, "Model::Volume");
 #endif
@@ -362,6 +380,22 @@ ModelInstance::ModelInstance(ModelObject *object, const ModelInstance &other)
 :   object(object), rotation(other.rotation), scaling_factor(other.scaling_factor), offset(other.offset)
 {}
 
+void
+ModelInstance::transform_mesh(TriangleMesh* mesh, bool dont_translate) const
+{
+    mesh->rotate_z(this->rotation);                 // rotate around mesh origin
+    mesh->scale(this->scaling_factor);              // scale around mesh origin
+    if (!dont_translate)
+        mesh->translate(this->offset.x, this->offset.y, 0);
+}
+
+void
+ModelInstance::transform_polygon(Polygon* polygon) const
+{
+    polygon->rotate(this->rotation, Point(0,0));    // rotate around polygon origin
+    polygon->scale(this->scaling_factor);           // scale around polygon origin
+}
+
 #ifdef SLIC3RXS
 REGISTER_CLASS(ModelInstance, "Model::Instance");
 #endif
diff --git a/xs/src/libslic3r/Model.hpp b/xs/src/libslic3r/Model.hpp
index dfcd75b4c..da21759d4 100644
--- a/xs/src/libslic3r/Model.hpp
+++ b/xs/src/libslic3r/Model.hpp
@@ -114,7 +114,7 @@ class ModelObject
 
     void invalidate_bounding_box();
 
-    //void raw_mesh(TriangleMesh* mesh) const;
+    void raw_mesh(TriangleMesh* mesh) const;
     //void mesh(TriangleMesh* mesh) const;
     //void instance_bounding_box(size_t instance_idx, BoundingBox* bb) const;
     //void center_around_origin();
@@ -149,6 +149,8 @@ class ModelVolume
     void material_id(t_model_material_id material_id);
     ModelMaterial* material() const;
     
+    ModelMaterial* assign_unique_material();
+    
     private:
     ModelObject* object;
     t_model_material_id _material_id;
@@ -166,7 +168,7 @@ class ModelInstance
     Pointf offset;              // in unscaled coordinates
     
     ModelObject* get_object() const { return this->object; };
-    void transform_mesh(TriangleMesh* mesh, bool dont_translate) const;
+    void transform_mesh(TriangleMesh* mesh, bool dont_translate = false) const;
     void transform_polygon(Polygon* polygon) const;
     
     private:
diff --git a/xs/src/libslic3r/TriangleMesh.cpp b/xs/src/libslic3r/TriangleMesh.cpp
index 77b11c5f8..04e892592 100644
--- a/xs/src/libslic3r/TriangleMesh.cpp
+++ b/xs/src/libslic3r/TriangleMesh.cpp
@@ -277,7 +277,7 @@ TriangleMesh::split() const
 }
 
 void
-TriangleMesh::merge(const TriangleMesh* mesh)
+TriangleMesh::merge(const TriangleMesh &mesh)
 {
     // reset stats and metadata
     int number_of_facets = this->stl.stats.number_of_facets;
@@ -285,13 +285,13 @@ TriangleMesh::merge(const TriangleMesh* mesh)
     this->repaired = false;
     
     // update facet count and allocate more memory
-    this->stl.stats.number_of_facets = number_of_facets + mesh->stl.stats.number_of_facets;
+    this->stl.stats.number_of_facets = number_of_facets + mesh.stl.stats.number_of_facets;
     this->stl.stats.original_num_facets = this->stl.stats.number_of_facets;
     stl_reallocate(&this->stl);
     
     // copy facets
-    for (int i = 0; i < mesh->stl.stats.number_of_facets; i++) {
-        this->stl.facet_start[number_of_facets + i] = mesh->stl.facet_start[i];
+    for (int i = 0; i < mesh.stl.stats.number_of_facets; i++) {
+        this->stl.facet_start[number_of_facets + i] = mesh.stl.facet_start[i];
     }
     
     // update size
diff --git a/xs/src/libslic3r/TriangleMesh.hpp b/xs/src/libslic3r/TriangleMesh.hpp
index b16f867eb..c35300c39 100644
--- a/xs/src/libslic3r/TriangleMesh.hpp
+++ b/xs/src/libslic3r/TriangleMesh.hpp
@@ -40,7 +40,7 @@ class TriangleMesh
     void align_to_origin();
     void rotate(double angle, Point* center);
     TriangleMeshPtrs split() const;
-    void merge(const TriangleMesh* mesh);
+    void merge(const TriangleMesh &mesh);
     void horizontal_projection(ExPolygons &retval) const;
     void convex_hull(Polygon* hull);
     void bounding_box(BoundingBoxf3* bb) const;
diff --git a/xs/xsp/Model.xsp b/xs/xsp/Model.xsp
index 8947558eb..d83b92b5e 100644
--- a/xs/xsp/Model.xsp
+++ b/xs/xsp/Model.xsp
@@ -107,6 +107,8 @@ ModelMaterial::attributes()
         %code%{ RETVAL = &THIS->instances; %};
     
     void invalidate_bounding_box();
+    TriangleMesh* raw_mesh()
+        %code%{ RETVAL = new TriangleMesh(); THIS->raw_mesh(RETVAL); %};
 
     Ref<BoundingBoxf3> _bounding_box(BoundingBoxf3* new_bbox = NULL)
         %code{%
@@ -186,6 +188,8 @@ ModelMaterial::attributes()
         %code%{ RETVAL = THIS->modifier; %};
     void set_modifier(bool modifier)
         %code%{ THIS->modifier = modifier; %};
+    
+    ModelMaterial* assign_unique_material();
 };
 
 
@@ -206,4 +210,7 @@ ModelMaterial::attributes()
         %code%{ THIS->scaling_factor = val; %};
     void set_offset(Pointf *offset)
         %code%{ THIS->offset = *offset; %};
+    
+    void transform_mesh(TriangleMesh* mesh, bool dont_translate = false) const;
+    void transform_polygon(Polygon* polygon) const;
 };
diff --git a/xs/xsp/TriangleMesh.xsp b/xs/xsp/TriangleMesh.xsp
index c6f7f7d04..ba5cdd0ce 100644
--- a/xs/xsp/TriangleMesh.xsp
+++ b/xs/xsp/TriangleMesh.xsp
@@ -29,7 +29,8 @@
     void align_to_origin();
     void rotate(double angle, Point* center);
     TriangleMeshPtrs split();
-    void merge(TriangleMesh* mesh);
+    void merge(TriangleMesh* mesh)
+        %code{% THIS->merge(*mesh); %};
     ExPolygons horizontal_projection()
         %code{% THIS->horizontal_projection(RETVAL); %};
     BoundingBoxf3* bounding_box()