diff --git a/lib/Slic3r.pm b/lib/Slic3r.pm
index 965d611b4..179405c97 100644
--- a/lib/Slic3r.pm
+++ b/lib/Slic3r.pm
@@ -148,6 +148,8 @@ sub thread_cleanup {
     *Slic3r::Geometry::BoundingBox::DESTROY = sub {};
     *Slic3r::Geometry::BoundingBoxf3::DESTROY = sub {};
     *Slic3r::Line::DESTROY                  = sub {};
+    *Slic3r::Model::DESTROY                 = sub {};
+    *Slic3r::Model::Object::DESTROY         = sub {};
     *Slic3r::Point::DESTROY                 = sub {};
     *Slic3r::Pointf::DESTROY                = sub {};
     *Slic3r::Pointf3::DESTROY               = sub {};
diff --git a/lib/Slic3r/Format/AMF.pm b/lib/Slic3r/Format/AMF.pm
index 4a2c1a61e..5dad1001e 100644
--- a/lib/Slic3r/Format/AMF.pm
+++ b/lib/Slic3r/Format/AMF.pm
@@ -35,8 +35,8 @@ sub write_file {
     printf $fh qq{<?xml version="1.0" encoding="UTF-8"?>\n};
     printf $fh qq{<amf unit="millimeter">\n};
     printf $fh qq{  <metadata type="cad">Slic3r %s</metadata>\n}, $Slic3r::VERSION;
-    for my $material_id (sort keys %{ $model->materials }) {
-        my $material = $model->materials->{$material_id};
+    for my $material_id (sort @{ $model->material_names }) {
+        my $material = $model->get_material($material_id);
         printf $fh qq{  <material id="%s">\n}, $material_id;
         for (keys %{$material->attributes}) {
              printf $fh qq{    <metadata type=\"%s\">%s</metadata>\n}, $_, $material->attributes->{$_};
diff --git a/lib/Slic3r/GUI/Plater.pm b/lib/Slic3r/GUI/Plater.pm
index 27beb25a7..dbe5e6f4b 100644
--- a/lib/Slic3r/GUI/Plater.pm
+++ b/lib/Slic3r/GUI/Plater.pm
@@ -471,8 +471,8 @@ sub reset {
     my $self = shift;
     
     @{$self->{objects}} = ();
-    $self->{model}->delete_all_objects;
-    $self->{print}->delete_all_objects;
+    $self->{model}->clear_objects;
+    $self->{print}->clear_objects;
     $self->{list}->DeleteAllItems;
     $self->object_list_changed;
     
@@ -542,7 +542,7 @@ sub rotate {
     
     {
         my $new_angle = $model_instance->rotation + $angle;
-        $_->rotation($new_angle) for @{ $model_object->instances };
+        $_->set_rotation($new_angle) for @{ $model_object->instances };
         $model_object->update_bounding_box;
         
         # update print
@@ -578,7 +578,7 @@ sub changescale {
             $range->[0] *= $variation;
             $range->[1] *= $variation;
         }
-        $_->scaling_factor($scale) for @{ $model_object->instances };
+        $_->set_scaling_factor($scale) for @{ $model_object->instances };
         $model_object->update_bounding_box;
         
         # update print
@@ -1108,10 +1108,11 @@ sub mouse_event {
         return if !$self->{drag_start_pos}; # concurrency problems
         my ($obj_idx, $instance_idx) = @{ $self->{drag_object} };
         my $model_object = $parent->{model}->objects->[$obj_idx];
-        $model_object->instances->[$instance_idx]->offset([
-            unscale($pos->[X] - $self->{drag_start_pos}[X]),
-            unscale($pos->[Y] - $self->{drag_start_pos}[Y]),
-        ]);
+        $model_object->instances->[$instance_idx]->set_offset(
+            Slic3r::Pointf->new(
+                unscale($pos->[X] - $self->{drag_start_pos}[X]),
+                unscale($pos->[Y] - $self->{drag_start_pos}[Y]),
+            ));
         $model_object->update_bounding_box;
         $parent->Refresh;
     } elsif ($event->Moving) {
diff --git a/lib/Slic3r/GUI/Plater/ObjectPartsPanel.pm b/lib/Slic3r/GUI/Plater/ObjectPartsPanel.pm
index 7b62bea52..5713acaba 100644
--- a/lib/Slic3r/GUI/Plater/ObjectPartsPanel.pm
+++ b/lib/Slic3r/GUI/Plater/ObjectPartsPanel.pm
@@ -158,7 +158,7 @@ sub selection_changed {
             
             # attach volume material config to settings panel
             my $volume = $self->{model_object}->volumes->[ $itemData->{volume_id} ];
-            my $material = $self->{model_object}->model->materials->{ $volume->material_id // '_' };
+            my $material = $self->{model_object}->model->get_material($volume->material_id // '_');
             $material //= $volume->assign_unique_material;
             $self->{staticbox}->SetLabel('Part Settings');
             $self->{settings_panel}->enable;
@@ -211,7 +211,7 @@ sub on_btn_load {
                 $new_volume->mesh->translate(@{$self->{model_object}->origin_translation}, 0);
                 
                 # set a default extruder value, since user can't add it manually
-                my $material = $self->{model_object}->model->materials->{$new_volume->material_id};
+                my $material = $self->{model_object}->model->get_material($new_volume->material_id);
                 $material->config->set_ifndef('extruder', 1);
                 
                 $self->{parts_changed} = 1;
diff --git a/lib/Slic3r/Model.pm b/lib/Slic3r/Model.pm
index 4c610540d..92dfa7245 100644
--- a/lib/Slic3r/Model.pm
+++ b/lib/Slic3r/Model.pm
@@ -1,12 +1,8 @@
 package Slic3r::Model;
-use Moo;
 
 use List::Util qw(first max);
 use Slic3r::Geometry qw(X Y Z move_points);
 
-has 'materials' => (is => 'ro', default => sub { {} });
-has 'objects'   => (is => 'ro', default => sub { [] });
-
 sub read_from_file {
     my $class = shift;
     my ($input_file) = @_;
@@ -16,7 +12,7 @@ sub read_from_file {
               : $input_file =~ /\.amf(\.xml)?$/i    ? Slic3r::Format::AMF->read_file($input_file)
               : die "Input file must have .stl, .obj or .amf(.xml) extension\n";
     
-    $_->input_file($input_file) for @{$model->objects};
+    $_->set_input_file($input_file) for @{$model->objects};
     return $model;
 }
 
@@ -39,11 +35,12 @@ sub add_object {
     if (@_ == 1) {
         # we have a Model::Object
         my ($object) = @_;
-        
+
         $new_object = $self->add_object(
             input_file          => $object->input_file,
             config              => $object->config,
             layer_height_ranges => $object->layer_height_ranges,    # TODO: clone!
+            origin_translation  => $object->origin_translation,
         );
         
         foreach my $volume (@{$object->volumes}) {
@@ -51,51 +48,43 @@ sub add_object {
         }
         
         $new_object->add_instance(
-            offset              => $_->offset,
+            offset              => [ @{$_->offset} ],
             rotation            => $_->rotation,
             scaling_factor      => $_->scaling_factor,
         ) for @{ $object->instances // [] };
     } else {
-        push @{$self->objects}, $new_object = Slic3r::Model::Object->new(model => $self, @_);
+        my (%args) = @_;
+        $new_object = $self->_add_object(
+            $args{input_file},
+            $args{config} // Slic3r::Config->new,
+            $args{layer_height_ranges} // [],
+            $args{origin_translation} // Slic3r::Pointf->new,
+            );
     }
     
     return $new_object;
 }
 
-sub delete_object {
-    my ($self, $obj_idx) = @_;
-    splice @{$self->objects}, $obj_idx, 1;
-}
-
-sub delete_all_objects {
-    my ($self) = @_;
-    @{$self->objects} = ();
-}
-
 sub set_material {
     my $self = shift;
     my ($material_id, $attributes) = @_;
     
-    return $self->materials->{$material_id} = Slic3r::Model::Material->new(
-        model       => $self,
-        attributes  => $attributes || {},
-    );
-}
-
-sub get_material {
-    my ($self, $material_id) = @_;
-    return $self->materials->{$material_id};
+    $attributes //= {};
+    
+    my $material = $self->_set_material($material_id);
+    $material->set_attribute($_, $attributes->{$_}) for keys %$attributes;
+    return $material;
 }
 
 sub duplicate_objects_grid {
     my ($self, $grid, $distance) = @_;
-    
+
     die "Grid duplication is not supported with multiple objects\n"
         if @{$self->objects} > 1;
-    
+
     my $object = $self->objects->[0];
-    @{$object->instances} = ();
-    
+    $object->clear_instances;
+
     my $size = $object->bounding_box->size;
     for my $x_copy (1..$grid->[X]) {
         for my $y_copy (1..$grid->[Y]) {
@@ -144,7 +133,7 @@ sub arrange_objects {
     my @positions = $self->_arrange(\@instance_sizes, $distance, $bb);
     
     foreach my $object (@{$self->objects}) {
-        $_->offset([ @{shift @positions} ]) for @{$object->instances};
+        $_->set_offset(Slic3r::Pointf->new(@{shift @positions})) for @{$object->instances};
         $object->update_bounding_box;
     }
 }
@@ -231,8 +220,10 @@ sub center_instances_around_point {
     
     foreach my $object (@{$self->objects}) {
         foreach my $instance (@{$object->instances}) {
-            $instance->offset->[X] += $shift[X];
-            $instance->offset->[Y] += $shift[Y];
+            $instance->set_offset(Slic3r::Pointf->new(
+                $instance->offset->x + $shift[X],
+                $instance->offset->y + $shift[Y],  #++
+            ));
         }
         $object->update_bounding_box;
     }
@@ -276,7 +267,7 @@ sub split_meshes {
         if (@{$object->volumes} > 1) {
             # We can't split meshes if there's more than one material, because
             # we can't group the resulting meshes by object afterwards
-            push @{$self->objects}, $object;
+            $self->_add_object($object);
             next;
         }
         
@@ -286,6 +277,7 @@ sub split_meshes {
                 input_file          => $object->input_file,
                 config              => $object->config->clone,
                 layer_height_ranges => $object->layer_height_ranges,   # TODO: this needs to be cloned
+                origin_translation  => $object->origin_translation,
             );
             $new_object->add_volume(
                 mesh        => $mesh,
@@ -312,57 +304,40 @@ sub get_material_name {
     my ($material_id) = @_;
     
     my $name;
-    if (exists $self->materials->{$material_id}) {
-        $name //= $self->materials->{$material_id}->attributes->{$_} for qw(Name name);
+    if ($self->has_material($material_id)) {
+        $name //= $self->get_material($material_id)
+            ->attributes->{$_} for qw(Name name);
     }
     $name //= $material_id;
     return $name;
 }
 
 package Slic3r::Model::Material;
-use Moo;
-
-has 'model'         => (is => 'ro', weak_ref => 1, required => 1);
-has 'attributes'    => (is => 'rw', default => sub { {} });
-has 'config'        => (is => 'rw', default => sub { Slic3r::Config->new });
 
 package Slic3r::Model::Object;
-use Moo;
 
 use File::Basename qw(basename);
 use List::Util qw(first sum);
 use Slic3r::Geometry qw(X Y Z rad2deg);
 
-has 'input_file'            => (is => 'rw');
-has 'model'                 => (is => 'ro', weak_ref => 1, required => 1);
-has 'volumes'               => (is => 'ro', default => sub { [] });
-has 'instances'             => (is => 'rw');
-has 'config'                => (is => 'rw', default => sub { Slic3r::Config->new });
-has 'layer_height_ranges'   => (is => 'rw', default => sub { [] }); # [ z_min, z_max, layer_height ]
-has '_bounding_box'         => (is => 'rw');
-has 'origin_translation'    => (is => 'ro', default => sub { Slic3r::Point->new });  # translation vector applied by center_around_origin() 
-
 sub add_volume {
     my $self = shift;
-    
+
     my $new_volume;
     if (@_ == 1) {
         # we have a Model::Volume
         my ($volume) = @_;
         
-        $new_volume = Slic3r::Model::Volume->new(
-            object      => $self,
-            material_id => $volume->material_id,
-            mesh        => $volume->mesh->clone,
-            modifier    => $volume->modifier,
-        );
+        $new_volume = $self->_add_volume(
+            $volume->material_id, $volume->mesh->clone, $volume->modifier);
         
+        # TODO: material_id can't be undef.
         if (defined $volume->material_id) {
             #  merge material attributes and config (should we rename materials in case of duplicates?)
-            if (my $material = $volume->object->model->materials->{$volume->material_id}) {
+            if (my $material = $volume->object->model->get_material($volume->material_id)) {
                 my %attributes = %{ $material->attributes };
-                if (exists $self->model->materials->{$volume->material_id}) {
-                    %attributes = (%attributes, %{ $self->model->materials->{$volume->material_id}->attributes })
+                if ($self->model->has_material($volume->material_id)) {
+                    %attributes = (%attributes, %{ $self->model->get_material($volume->material_id)->attributes })
                 }
                 my $new_material = $self->model->set_material($volume->material_id, {%attributes});
                 $new_material->config->apply($material->config);
@@ -370,10 +345,10 @@ sub add_volume {
         }
     } else {
         my %args = @_;
-        $new_volume = Slic3r::Model::Volume->new(
-            object => $self,
-            %args,
-        );
+        $new_volume = $self->_add_volume(
+            $args{material_id},
+            $args{mesh},
+            $args{modifier} // 0);
     }
     
     if (defined $new_volume->material_id && !defined $self->model->get_material($new_volume->material_id)) {
@@ -381,33 +356,19 @@ sub add_volume {
         $self->model->set_material($new_volume->material_id);
     }
     
-    push @{$self->volumes}, $new_volume;
-    
-    # invalidate cached bounding box
-    $self->_bounding_box(undef);
+    $self->invalidate_bounding_box();
     
     return $new_volume;
 }
 
-sub delete_volume {
-    my ($self, $i) = @_;
-    splice @{$self->volumes}, $i, 1;
-}
-
 sub add_instance {
     my $self = shift;
     my %params = @_;
-    
-    $self->instances([]) if !defined $self->instances;
-    push @{$self->instances}, my $i = Slic3r::Model::Instance->new(object => $self, %params);
-    $self->_bounding_box(undef);
-    return $i;
-}
 
-sub delete_last_instance {
-    my ($self) = @_;
-    pop @{$self->instances};
-    $self->_bounding_box(undef);
+    return $self->_add_instance(
+        $params{rotation} // 0,
+        $params{scaling_factor} // 1,
+        $params{offset} // []);
 }
 
 sub instances_count {
@@ -487,8 +448,9 @@ sub center_around_origin {
     
     if (defined $self->instances) {
         foreach my $instance (@{ $self->instances }) {
-            $instance->offset->[X] -= $shift[X];
-            $instance->offset->[Y] -= $shift[Y];
+            $instance->set_offset(Slic3r::Pointf->new(
+                $instance->offset->x - $shift[X],
+                $instance->offset->y - $shift[Y]));
         }
         $self->update_bounding_box;
     }
@@ -511,7 +473,7 @@ sub rotate_x {
     $angle = rad2deg($angle);
     
     $_->mesh->rotate_x($angle) for @{$self->volumes};
-    $self->_bounding_box(undef);
+    $self->invalidate_bounding_box;
 }
 
 sub materials_count {
@@ -577,22 +539,22 @@ sub cut {
     
     # clone this one
     my $upper = Slic3r::Model::Object->new(
-        input_file          => $self->input_file,
-        model               => $self->model,
-        config              => $self->config->clone,
-        layer_height_ranges => $self->layer_height_ranges,
-        origin_translation  => $self->origin_translation->clone,
+        $self->model,
+        $self->input_file,
+        $self->config,  # config is cloned by new()
+        $self->layer_height_ranges,
+        $self->origin_translation,
     );
     my $lower = Slic3r::Model::Object->new(
-        input_file          => $self->input_file,
-        model               => $self->model,
-        config              => $self->config->clone,
-        layer_height_ranges => $self->layer_height_ranges,
-        origin_translation  => $self->origin_translation->clone,
+        $self->model,
+        $self->input_file,
+        $self->config,  # config is cloned by new()
+        $self->layer_height_ranges,
+        $self->origin_translation,
     );
     foreach my $instance (@{$self->instances}) {
-        $upper->add_instance(offset => $instance->offset);
-        $lower->add_instance(offset => $instance->offset);
+        $upper->add_instance(offset => [ @{$instance->offset} ]);
+        $lower->add_instance(offset => [ @{$instance->offset} ]);
     }
     
     foreach my $volume (@{$self->volumes}) {
@@ -632,29 +594,17 @@ sub cut {
 }
 
 package Slic3r::Model::Volume;
-use Moo;
-
-has 'object'            => (is => 'ro', weak_ref => 1, required => 1);
-has 'material_id'       => (is => 'rw');
-has 'mesh'              => (is => 'rw', required => 1);
-has 'modifier'          => (is => 'rw', defualt => sub { 0 });
 
 sub assign_unique_material {
     my ($self) = @_;
     
     my $model = $self->object->model;
-    my $material_id = 1 + scalar keys %{$model->materials};
+    my $material_id = 1 + $model->material_count;
     $self->material_id($material_id);
     return $model->set_material($material_id);
 }
 
 package Slic3r::Model::Instance;
-use Moo;
-
-has 'object'            => (is => 'ro', weak_ref => 1, required => 1);
-has 'rotation'          => (is => 'rw', default => sub { 0 });  # around mesh center point
-has 'scaling_factor'    => (is => 'rw', default => sub { 1 });
-has 'offset'            => (is => 'rw');  # must be arrayref in *unscaled* coordinates
 
 sub transform_mesh {
     my ($self, $mesh, $dont_translate) = @_;
diff --git a/lib/Slic3r/Print.pm b/lib/Slic3r/Print.pm
index 7626bba81..050e4c39d 100644
--- a/lib/Slic3r/Print.pm
+++ b/lib/Slic3r/Print.pm
@@ -86,7 +86,7 @@ sub apply_config {
                     $new->apply_dynamic($model_object_config);
                 }
                 if (defined $volume->material_id) {
-                    my $material_config = $object->model_object->model->materials->{$volume->material_id}->config->clone;
+                    my $material_config = $object->model_object->model->get_material($volume->material_id)->config->clone;
                     $material_config->normalize;
                     $new->apply_dynamic($material_config);
                 }
@@ -104,9 +104,8 @@ sub apply_config {
     if ($rearrange_regions) {
         # the current subdivision of regions does not make sense anymore.
         # we need to remove all objects and re-add them
-        my @model_objects = map $_->model_object, @{$self->objects};
-        $self->delete_all_objects;
-        $self->add_model_object($_) for @model_objects;
+        $self->clear_objects;
+        $self->add_model_object($_->model_object) for @{$self->objects};
     }
 }
 
@@ -138,7 +137,7 @@ sub add_model_object {
         $config->apply_dynamic($object_config);
         
         if (defined $volume->material_id) {
-            my $material_config = $object->model->materials->{ $volume->material_id }->config->clone;
+            my $material_config = $object->model->get_material($volume->material_id)->config->clone;
             $material_config->normalize;
             $config->apply_dynamic($material_config);
         }
@@ -201,7 +200,7 @@ sub delete_object {
     $self->_state->invalidate(STEP_BRIM);
 }
 
-sub delete_all_objects {
+sub clear_objects {
     my ($self) = @_;
     
     @{$self->objects} = ();
@@ -220,9 +219,9 @@ sub reload_object {
     # For now we just re-add all objects since we haven't implemented this incremental logic yet.
     # This should also check whether object volumes (parts) have changed.
     
-    my @model_objects = map $_->model_object, @{$self->objects};
-    $self->delete_all_objects;
-    $self->add_model_object($_) for @model_objects;
+    my @models_objects = map $_->model_object, @{$self->objects};
+    $self->clear_objects;
+    $self->add_model_object($_) for @models_objects;
 }
 
 sub validate {
@@ -1116,7 +1115,7 @@ sub auto_assign_extruders {
     foreach my $i (0..$#{$model_object->volumes}) {
         my $volume = $model_object->volumes->[$i];
         if (defined $volume->material_id) {
-            my $material = $model_object->model->materials->{ $volume->material_id };
+            my $material = $model_object->model->get_material($volume->material_id);
             my $config = $material->config;
             my $extruder_id = $i + 1;
             $config->set_ifndef('extruder', $extruder_id);
diff --git a/lib/Slic3r/Print/Object.pm b/lib/Slic3r/Print/Object.pm
index e41f6813f..a43123a88 100644
--- a/lib/Slic3r/Print/Object.pm
+++ b/lib/Slic3r/Print/Object.pm
@@ -10,7 +10,7 @@ use Slic3r::Print::State ':steps';
 use Slic3r::Surface ':types';
 
 has 'print'             => (is => 'ro', weak_ref => 1, required => 1);
-has 'model_object'      => (is => 'ro', required => 1);
+has 'model_object'      => (is => 'ro', required => 1);  # caller is responsible for holding the Model object
 has 'region_volumes'    => (is => 'rw', default => sub { [] });  # by region_id
 has 'copies'            => (is => 'ro');  # Slic3r::Point objects in scaled G-code coordinates
 has 'config'            => (is => 'ro', default => sub { Slic3r::Config::PrintObject->new });
diff --git a/lib/Slic3r/Print/Simple.pm b/lib/Slic3r/Print/Simple.pm
index 794661d8a..6e64cab5f 100644
--- a/lib/Slic3r/Print/Simple.pm
+++ b/lib/Slic3r/Print/Simple.pm
@@ -44,15 +44,15 @@ sub set_model {
     my ($self, $model) = @_;
     
     # make method idempotent so that the object is reusable
-    $self->_print->delete_all_objects;
+    $self->_print->clear_objects;
     
     # make sure all objects have at least one defined instance
     my $need_arrange = $model->add_default_instances;
     
     # apply scaling and rotation supplied from command line if any
     foreach my $instance (map @{$_->instances}, @{$model->objects}) {
-        $instance->scaling_factor($instance->scaling_factor * $self->scale);
-        $instance->rotation($instance->rotation + $self->rotate);
+        $instance->set_scaling_factor($instance->scaling_factor * $self->scale);
+        $instance->set_rotation($instance->rotation + $self->rotate);
     }
     
     if ($self->duplicate_grid->[X] > 1 || $self->duplicate_grid->[Y] > 1) {
diff --git a/slic3r.pl b/slic3r.pl
index d2c08073c..ed25c6b8d 100755
--- a/slic3r.pl
+++ b/slic3r.pl
@@ -172,7 +172,6 @@ if (@ARGV) {  # slicing from command line
         
         $sprint->apply_config($config);
         $sprint->set_model($model);
-        undef $model;  # free memory
         
         if ($opt{export_svg}) {
             $sprint->export_svg;
diff --git a/xs/MANIFEST b/xs/MANIFEST
index d5c52dd53..0fdceff84 100644
--- a/xs/MANIFEST
+++ b/xs/MANIFEST
@@ -1673,6 +1673,7 @@ src/Geometry.hpp
 src/Layer.hpp
 src/Line.cpp
 src/Line.hpp
+src/Model.cpp
 src/Model.hpp
 src/MultiPoint.cpp
 src/MultiPoint.hpp
@@ -1742,6 +1743,7 @@ xsp/ExtrusionPath.xsp
 xsp/Flow.xsp
 xsp/Geometry.xsp
 xsp/Line.xsp
+xsp/Model.xsp
 xsp/my.map
 xsp/mytype.map
 xsp/Point.xsp
diff --git a/xs/lib/Slic3r/XS.pm b/xs/lib/Slic3r/XS.pm
index 9cbd1d2f9..ddecad87e 100644
--- a/xs/lib/Slic3r/XS.pm
+++ b/xs/lib/Slic3r/XS.pm
@@ -13,31 +13,16 @@ use overload
     '@{}' => sub { $_[0]->arrayref },
     'fallback' => 1;
 
-package Slic3r::Line::Ref;
-our @ISA = 'Slic3r::Line';
-
-sub DESTROY {}
-
 package Slic3r::Point;
 use overload
     '@{}' => sub { $_[0]->arrayref },
     'fallback' => 1;
 
-package Slic3r::Point::Ref;
-our @ISA = 'Slic3r::Point';
-
-sub DESTROY {}
-
 package Slic3r::Pointf;
 use overload
     '@{}' => sub { [ $_[0]->x, $_[0]->y ] },  #,
     'fallback' => 1;
 
-package Slic3r::Pointf::Ref;
-our @ISA = 'Slic3r::Pointf';
-
-sub DESTROY {}
-
 package Slic3r::Pointf3;
 use overload
     '@{}' => sub { [ $_[0]->x, $_[0]->y, $_[0]->z ] },  #,
@@ -48,21 +33,11 @@ use overload
     '@{}' => sub { $_[0]->arrayref },
     'fallback' => 1;
 
-package Slic3r::ExPolygon::Ref;
-our @ISA = 'Slic3r::ExPolygon';
-
-sub DESTROY {}
-
 package Slic3r::Polyline;
 use overload
     '@{}' => sub { $_[0]->arrayref },
     'fallback' => 1;
 
-package Slic3r::Polyline::Ref;
-our @ISA = 'Slic3r::Polyline';
-
-sub DESTROY {}
-
 package Slic3r::Polyline::Collection;
 use overload
     '@{}' => sub { $_[0]->arrayref },
@@ -73,11 +48,6 @@ use overload
     '@{}' => sub { $_[0]->arrayref },
     'fallback' => 1;
 
-package Slic3r::Polygon::Ref;
-our @ISA = 'Slic3r::Polygon';
-
-sub DESTROY {}
-
 package Slic3r::ExPolygon::Collection;
 use overload
     '@{}' => sub { $_[0]->arrayref },
@@ -96,11 +66,6 @@ sub new {
     return $self;
 }
 
-package Slic3r::ExtrusionPath::Collection::Ref;
-our @ISA = 'Slic3r::ExtrusionPath::Collection';
-
-sub DESTROY {}
-
 package Slic3r::ExtrusionLoop;
 use overload
     '@{}' => sub { $_[0]->arrayref },
@@ -114,11 +79,6 @@ sub new_from_paths {
     return $loop;
 }
 
-package Slic3r::ExtrusionLoop::Ref;
-our @ISA = 'Slic3r::ExtrusionLoop';
-
-sub DESTROY {}
-
 package Slic3r::ExtrusionPath;
 use overload
     '@{}' => sub { $_[0]->arrayref },
@@ -148,11 +108,6 @@ sub clone {
     );
 }
 
-package Slic3r::ExtrusionPath::Ref;
-our @ISA = 'Slic3r::ExtrusionPath';
-
-sub DESTROY {}
-
 package Slic3r::Flow;
 
 sub new {
@@ -213,14 +168,38 @@ sub clone {
     );
 }
 
-package Slic3r::Surface::Ref;
-our @ISA = 'Slic3r::Surface';
-
-sub DESTROY {}
-
 package Slic3r::Surface::Collection;
 use overload
     '@{}' => sub { $_[0]->arrayref },
     'fallback' => 1;
 
+package main;
+for my $class (qw(
+        Slic3r::Config
+        Slic3r::Config::Print
+        Slic3r::ExPolygon
+        Slic3r::ExtrusionLoop
+        Slic3r::ExtrusionPath
+        Slic3r::ExtrusionPath::Collection
+        Slic3r::Geometry::BoundingBoxf3
+        Slic3r::Line
+        Slic3r::Model
+        Slic3r::Model::Instance
+        Slic3r::Model::Material
+        Slic3r::Model::Object
+        Slic3r::Model::Volume
+        Slic3r::Point
+        Slic3r::Pointf
+        Slic3r::Pointf3
+        Slic3r::Polygon
+        Slic3r::Polyline
+        Slic3r::Surface
+        Slic3r::TriangleMesh
+    ))
+{
+    no strict 'refs';
+    my $ref_class = $class . "::Ref";
+    eval "package $ref_class; our \@ISA = '$class'; sub DESTROY {};";
+}
+
 1;
diff --git a/xs/src/Model.cpp b/xs/src/Model.cpp
new file mode 100644
index 000000000..aee79702d
--- /dev/null
+++ b/xs/src/Model.cpp
@@ -0,0 +1,325 @@
+#include "Model.hpp"
+#ifdef SLIC3RXS
+#include "perlglue.hpp"
+#endif
+
+
+namespace Slic3r {
+
+Model::Model() {}
+
+Model::Model(const Model &other)
+{
+    objects.reserve(other.objects.size());
+
+    for (ModelMaterialMap::const_iterator i = other.materials.begin();
+        i != other.materials.end(); ++i)
+    {
+        ModelMaterial *copy = new ModelMaterial(*i->second);
+        copy->model = this;
+        materials[i->first] = copy;
+
+    }
+
+    for (ModelObjectPtrs::const_iterator i = other.objects.begin();
+        i != other.objects.end(); ++i)
+    {
+        ModelObject *copy = new ModelObject(**i);
+        copy->model = this;
+        objects.push_back(copy);
+    }
+}
+
+Model::~Model()
+{
+    this->clear_objects();
+    this->clear_materials();
+}
+
+ModelObject*
+Model::add_object(const std::string &input_file, const DynamicPrintConfig &config,
+    const t_layer_height_ranges &layer_height_ranges, const Pointf &origin_translation)
+{
+    ModelObject* object = new ModelObject(this, input_file, config,
+        layer_height_ranges, origin_translation);
+    this->objects.push_back(object);
+    return object;
+}
+
+void
+Model::delete_object(size_t idx)
+{
+    ModelObjectPtrs::iterator i = this->objects.begin() + idx;
+    delete *i;
+    this->objects.erase(i);
+}
+
+void
+Model::clear_objects()
+{
+    for (size_t i = this->objects.size()-1; i >= 0; --i)
+        this->delete_object(i);
+}
+
+void
+Model::delete_material(t_model_material_id material_id)
+{
+    ModelMaterialMap::iterator i = this->materials.find(material_id);
+    if (i != this->materials.end()) {
+        delete i->second;
+        this->materials.erase(i);
+    }
+}
+
+void
+Model::clear_materials()
+{
+    while (!this->materials.empty())
+        this->delete_material( this->materials.begin()->first );
+}
+
+ModelMaterial *
+Model::set_material(t_model_material_id material_id)
+{
+    ModelMaterialMap::iterator i = this->materials.find(material_id);
+    
+    ModelMaterial *mat;
+    if (i == this->materials.end()) {
+        mat = this->materials[material_id] = new ModelMaterial(this);
+    } else {
+        mat = i->second;
+    }
+    
+    return mat;
+}
+
+/*
+void
+Model::duplicate_objects_grid(unsigned int x, unsigned int y, coordf_t distance)
+{
+    if (this->objects.size() > 1) throw "Grid duplication is not supported with multiple objects";
+    if (this->objects.empty()) throw "No objects!";
+
+    ModelObject* object = this->objects.front();
+    object->clear_instances();
+
+    BoundingBoxf3 bb;
+    object->bounding_box(&bb);
+    Sizef3 size = bb.size();
+
+    for (unsigned int x_copy = 1; x_copy <= x; ++x_copy) {
+        for (unsigned int y_copy = 1; y_copy <= y; ++y_copy) {
+            ModelInstance* instance = object->add_instance();
+            instance->offset.x = (size.x + distance) * (x_copy-1);
+            instance->offset.y = (size.y + distance) * (y_copy-1);
+        }
+    }
+}
+*/
+
+bool
+Model::has_objects_with_no_instances() const
+{
+    for (ModelObjectPtrs::const_iterator i = this->objects.begin();
+        i != this->objects.end(); ++i)
+    {
+        if ((*i)->instances.empty()) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+#ifdef SLIC3RXS
+REGISTER_CLASS(Model, "Model");
+#endif
+
+
+ModelMaterial::ModelMaterial(Model *model) : model(model) {}
+
+void
+ModelMaterial::apply(const t_model_material_attributes &attributes)
+{
+    this->attributes.insert(attributes.begin(), attributes.end());
+}
+
+
+#ifdef SLIC3RXS
+REGISTER_CLASS(ModelMaterial, "Model::Material");
+#endif
+
+
+ModelObject::ModelObject(Model *model, const std::string &input_file,
+    const DynamicPrintConfig &config, const t_layer_height_ranges &layer_height_ranges,
+    const Pointf &origin_translation)
+:   model(model),
+    input_file(input_file),
+    config(config),
+    layer_height_ranges(layer_height_ranges),
+    origin_translation(origin_translation),
+    _bounding_box_valid(false)
+{
+}
+
+ModelObject::ModelObject(const ModelObject &other)
+:   model(other.model),
+    input_file(other.input_file),
+    instances(),
+    volumes(),
+    config(other.config),
+    layer_height_ranges(other.layer_height_ranges),
+    origin_translation(other.origin_translation),
+    _bounding_box(other._bounding_box),
+    _bounding_box_valid(other._bounding_box_valid)
+{
+    volumes.reserve(other.volumes.size());
+    instances.reserve(other.instances.size());
+
+    for (ModelVolumePtrs::const_iterator i = other.volumes.begin();
+        i != other.volumes.end(); ++i)
+    {
+        ModelVolume *v = new ModelVolume(**i);
+        v->object = this;
+        volumes.push_back(v);
+
+    }
+
+    for (ModelInstancePtrs::const_iterator i = other.instances.begin();
+        i != other.instances.end(); ++i)
+    {
+        ModelInstance *in = new ModelInstance(**i);
+        in->object = this;
+        instances.push_back(in);
+    }
+}
+
+ModelObject::~ModelObject()
+{
+    this->clear_volumes();
+    this->clear_instances();
+}
+
+ModelVolume *
+ModelObject::add_volume(const t_model_material_id &material_id,
+        const TriangleMesh &mesh, bool modifier)
+{
+    ModelVolume *v = new ModelVolume(this, material_id, mesh, modifier);
+    this->volumes.push_back(v);
+    this->invalidate_bounding_box();
+    return v;
+}
+
+void
+ModelObject::delete_volume(size_t idx)
+{
+    ModelVolumePtrs::iterator i = this->volumes.begin() + idx;
+    delete *i;
+    this->volumes.erase(i);
+    this->invalidate_bounding_box();
+}
+
+void
+ModelObject::clear_volumes()
+{
+    for (size_t i = this->volumes.size()-1; i >= 0; --i)
+        this->delete_volume(i);
+}
+
+ModelInstance *
+ModelObject::add_instance(double rotation, double scaling_factor,
+    Pointf offset)
+{
+    ModelInstance *i = new ModelInstance(
+        this, rotation, scaling_factor, offset);
+    this->instances.push_back(i);
+    this->invalidate_bounding_box();
+    return i;
+}
+
+void
+ModelObject::delete_instance(size_t idx)
+{
+    ModelInstancePtrs::iterator i = this->instances.begin() + idx;
+    delete *i;
+    this->instances.erase(i);
+    this->invalidate_bounding_box();
+}
+
+void
+ModelObject::delete_last_instance()
+{
+    this->delete_instance(this->instances.size() - 1);
+}
+
+void
+ModelObject::clear_instances()
+{
+    for (size_t i = 0; i < this->instances.size(); ++i)
+        this->delete_instance(i);
+}
+
+void
+ModelObject::invalidate_bounding_box()
+{
+    this->_bounding_box_valid = false;
+}
+
+#ifdef SLIC3RXS
+REGISTER_CLASS(ModelObject, "Model::Object");
+
+SV*
+ModelObject::to_SV_ref() {
+    SV* sv = newSV(0);
+    sv_setref_pv( sv, perl_class_name_ref(this), this );
+    return sv;
+}
+#endif
+
+
+ModelVolume::ModelVolume(ModelObject* object, const t_model_material_id &material_id,
+    const TriangleMesh &mesh, bool modifier)
+:   object(object),
+    material_id(material_id),
+    mesh(mesh),
+    modifier(modifier)
+{
+}
+
+#ifdef SLIC3RXS
+REGISTER_CLASS(ModelVolume, "Model::Volume");
+
+SV*
+ModelVolume::to_SV_ref() {
+    SV* sv = newSV(0);
+    sv_setref_pv( sv, perl_class_name_ref(this), this );
+    return sv;
+}
+#endif
+
+
+ModelInstance::ModelInstance(ModelObject *object, double rotation,
+    double scaling_factor, const Pointf &offset)
+:   object(object),
+    rotation(rotation),
+    scaling_factor(scaling_factor),
+    offset(offset)
+{
+}
+
+ModelInstance::~ModelInstance()
+{
+}
+
+#ifdef SLIC3RXS
+REGISTER_CLASS(ModelInstance, "Model::Instance");
+
+SV*
+ModelInstance::to_SV_ref() {
+    SV* sv = newSV(0);
+    sv_setref_pv( sv, perl_class_name_ref(this), this );
+    return sv;
+}
+#endif
+
+}
diff --git a/xs/src/Model.hpp b/xs/src/Model.hpp
index 6e16e8faa..b0e04732f 100644
--- a/xs/src/Model.hpp
+++ b/xs/src/Model.hpp
@@ -2,7 +2,7 @@
 #define slic3r_Model_hpp_
 
 #include <myinit.h>
-#include "Config.hpp"
+#include "PrintConfig.hpp"
 #include "Layer.hpp"
 #include "Point.hpp"
 #include "TriangleMesh.hpp"
@@ -22,30 +22,40 @@ typedef std::string t_model_material_id;
 typedef std::string t_model_material_attribute;
 typedef std::map<t_model_material_attribute,std::string> t_model_material_attributes;
 
+typedef std::map<t_model_material_id,ModelMaterial*> ModelMaterialMap;
+typedef std::vector<ModelObject*> ModelObjectPtrs;
+typedef std::vector<ModelVolume*> ModelVolumePtrs;
+typedef std::vector<ModelInstance*> ModelInstancePtrs;
+
 class Model
 {
     public:
-    std::map<t_model_material_id,ModelMaterial*> materials;
-    std::vector<ModelObject*> objects;
+    ModelMaterialMap materials;
+    ModelObjectPtrs objects;
     
     Model();
+    Model(const Model &other);
     ~Model();
-    ModelObject* add_object(const ModelObject &object);
-    void delete_object(size_t obj_idx);
-    void delete_all_objects();
-    void set_material(t_model_material_id material_id, const t_model_material_attributes &attributes);
-    void duplicate_objects_grid(coordf_t x, coordf_t y, coordf_t distance);
-    void duplicate_objects(size_t copies_num, coordf_t distance, const BoundingBox &bb);
-    void arrange_objects(coordf_t distance, const BoundingBox &bb);
-    void duplicate(size_t copies_num, coordf_t distance, const BoundingBox &bb);
+    ModelObject* add_object(const std::string &input_file, const DynamicPrintConfig &config,
+        const t_layer_height_ranges &layer_height_ranges, const Pointf &origin_translation);
+    void delete_object(size_t idx);
+    void clear_objects();
+    void delete_material(t_model_material_id material_id);
+    void clear_materials();
+    ModelMaterial *set_material(t_model_material_id material_id);
+    // void duplicate_objects_grid(unsigned int x, unsigned int y, coordf_t distance);
+    // void duplicate_objects(size_t copies_num, coordf_t distance, const BoundingBox &bb);
+    // void arrange_objects(coordf_t distance, const BoundingBox &bb);
+    // void duplicate(size_t copies_num, coordf_t distance, const BoundingBox &bb);
     bool has_objects_with_no_instances() const;
-    void bounding_box(BoundingBox* bb) const;
-    void align_to_origin();
-    void center_instances_around_point(const Pointf &point);
-    void translate(coordf_t x, coordf_t y, coordf_t z);
-    void mesh(TriangleMesh* mesh) const;
-    void split_meshes();
-    std::string get_material_name(t_model_material_id material_id);
+    // void bounding_box(BoundingBox* bb) const;
+    // void align_to_origin();
+    // void center_instances_around_point(const Pointf &point);
+    // void translate(coordf_t x, coordf_t y, coordf_t z);
+    // void mesh(TriangleMesh* mesh) const;
+    // void split_meshes();
+    // std::string get_material_name(t_model_material_id material_id);
+
     
     private:
     void _arrange(const std::vector<Size> &sizes, coordf_t distance, const BoundingBox &bb) const;
@@ -56,7 +66,10 @@ class ModelMaterial
     public:
     Model* model;
     t_model_material_attributes attributes;
-    DynamicConfig config;
+    DynamicPrintConfig config;
+
+    ModelMaterial(Model *model);
+    void apply(const t_model_material_attributes &attributes);
 };
 
 class ModelObject
@@ -64,16 +77,32 @@ class ModelObject
     public:
     Model* model;
     std::string input_file;
-    std::vector<ModelInstance*> instances;
-    std::vector<ModelVolume*> volumes;
-    DynamicConfig config;
+    ModelInstancePtrs instances;
+    ModelVolumePtrs volumes;
+    DynamicPrintConfig config;
     t_layer_height_ranges layer_height_ranges;
+    Pointf origin_translation;
+    BoundingBoxf3 _bounding_box;
+    bool _bounding_box_valid;
     
-    ModelObject();
+    ModelObject(Model *model, const std::string &input_file, const DynamicPrintConfig &config,
+        const t_layer_height_ranges &layer_height_ranges, const Pointf &origin_translation);
+    ModelObject(const ModelObject &other);
     ~ModelObject();
-    ModelInstance* add_instance(const ModelInstance &instance);
-    ModelVolume* add_volume(const ModelVolume &volume);
+
+    ModelVolume* add_volume(const t_model_material_id &material_id,
+        const TriangleMesh &mesh, bool modifier);
+    void delete_volume(size_t idx);
+    void clear_volumes();
+
+    ModelInstance *add_instance(double rotation=0, double scaling_factor = 1,
+        Pointf offset = Pointf(0, 0));
+    void delete_instance(size_t idx);
     void delete_last_instance();
+    void clear_instances();
+
+    void invalidate_bounding_box();
+
     void raw_mesh(TriangleMesh* mesh) const;
     void mesh(TriangleMesh* mesh) const;
     void instance_bounding_box(size_t instance_idx, BoundingBox* bb) const;
@@ -84,8 +113,11 @@ class ModelObject
     size_t facets_count() const;
     bool needed_repair() const;
     
+    #ifdef SLIC3RXS
+    SV* to_SV_ref();
+    #endif
+
     private:
-    BoundingBox bb;
     void update_bounding_box();
 };
 
@@ -95,18 +127,34 @@ class ModelVolume
     ModelObject* object;
     t_model_material_id material_id;
     TriangleMesh mesh;
+    bool modifier;
+
+    ModelVolume(ModelObject *object, const t_model_material_id &material_id,
+        const TriangleMesh &mesh, bool modifier);
+
+    #ifdef SLIC3RXS
+    SV* to_SV_ref();
+    #endif
 };
 
 class ModelInstance
 {
     public:
     ModelObject* object;
-    double rotation;
+    double rotation;            // around mesh center point
     double scaling_factor;
-    Pointf offset;
+    Pointf offset;              // in unscaled coordinates
+
+    ModelInstance(ModelObject *object, double rotation, double scaling_factor,
+        const Pointf &offset);
+    ~ModelInstance();
     
     void transform_mesh(TriangleMesh* mesh, bool dont_translate) const;
     void transform_polygon(Polygon* polygon) const;
+
+    #ifdef SLIC3RXS
+    SV* to_SV_ref();
+    #endif
 };
 
 }
diff --git a/xs/src/perlglue.hpp b/xs/src/perlglue.hpp
index ed767ef3e..efe10aa45 100644
--- a/xs/src/perlglue.hpp
+++ b/xs/src/perlglue.hpp
@@ -8,12 +8,17 @@ struct ClassTraits {
     static const char* name;
     static const char* name_ref; 
 };
-    
-#define REGISTER_CLASS(cname,perlname)                                               \
-    class cname;                                                                     \
+
+// use this for typedefs for which the forward prototype
+// in REGISTER_CLASS won't work
+#define __REGISTER_CLASS(cname, perlname)                                            \
     template <>const char* ClassTraits<cname>::name = "Slic3r::" perlname;           \
     template <>const char* ClassTraits<cname>::name_ref = "Slic3r::" perlname "::Ref"; 
-    
+
+#define REGISTER_CLASS(cname,perlname)                                               \
+    class cname;                                                                     \
+    __REGISTER_CLASS(cname, perlname);
+
 template<class T>
 const char* perl_class_name(const T*) { return ClassTraits<T>::name; }
 template<class T>
diff --git a/xs/xsp/Model.xsp b/xs/xsp/Model.xsp
new file mode 100644
index 000000000..43356a3bc
--- /dev/null
+++ b/xs/xsp/Model.xsp
@@ -0,0 +1,233 @@
+%module{Slic3r::XS};
+
+%{
+#include <myinit.h>
+#include "Model.hpp"
+#include "PrintConfig.hpp"
+#include "perlglue.hpp"
+%}
+
+%name{Slic3r::Model} class Model {
+    Model();
+    ~Model();
+
+    Clone<Model> clone()
+        %code%{ RETVAL = THIS; %};
+
+    Ref<ModelObject> _add_object(std::string input_file,
+            DynamicPrintConfig* config,
+            t_layer_height_ranges layer_height_ranges,
+            Pointf* origin_translation)
+        %code%{
+            RETVAL = THIS->add_object(input_file, *config, layer_height_ranges,
+                *origin_translation);
+        %};
+    
+    void delete_object(size_t idx);
+    void clear_objects();
+    void delete_material(t_model_material_id material_id);
+    void clear_materials();
+    
+    %name{_set_material} Ref<ModelMaterial> set_material(t_model_material_id material_id)
+        %code%{ RETVAL = THIS->set_material(material_id); %};
+
+    Ref<ModelMaterial> get_material(t_model_material_id material_id)
+        %code%{
+            ModelMaterialMap::iterator i = THIS->materials.find(material_id);
+            if (i == THIS->materials.end()) {
+                XSRETURN_UNDEF;
+            }
+
+            RETVAL = i->second;
+        %};
+
+    bool has_material(t_model_material_id material_id) const
+        %code%{
+            RETVAL = (THIS->materials.find(material_id) != THIS->materials.end());
+        %};
+
+    std::vector<std::string> material_names() const
+        %code%{
+            for (ModelMaterialMap::iterator i = THIS->materials.begin();
+                i != THIS->materials.end(); ++i)
+            {
+                RETVAL.push_back(i->first);
+            }
+        %};
+
+    size_t material_count() const
+        %code%{ RETVAL = THIS->materials.size(); %};
+
+    // void duplicate_objects_grid(coordf_t x, coordf_t y, coordf_t distance);
+    // void duplicate_objects(size_t copies_num, coordf_t distance, const BoundingBox &bb);
+    // void arrange_objects(coordf_t distance, const BoundingBox &bb);
+    // void duplicate(size_t copies_num, coordf_t distance, const BoundingBox &bb);
+    bool has_objects_with_no_instances() const;
+    // void bounding_box(BoundingBox* bb) const;
+    // void center_instances_around_point(const Pointf &point);
+    // void align_instances_to_origin();
+    // void translate(coordf_t x, coordf_t y, coordf_t z);
+    // void mesh(TriangleMesh* mesh) const;
+    // void split_meshes();
+    // std::string get_material_name(t_model_material_id material_id);
+
+    ModelObjectPtrs *objects()
+        %code%{
+            if (THIS->objects.empty()) {
+                XSRETURN_UNDEF;
+            }
+
+            RETVAL = &THIS->objects;
+        %};
+};
+
+
+%name{Slic3r::Model::Material} class ModelMaterial {
+    ~ModelMaterial();
+
+    Ref<Model> model()
+        %code%{ RETVAL = THIS->model; %};
+
+    Ref<DynamicPrintConfig> config()
+        %code%{ RETVAL = &THIS->config; %};
+    
+    std::string get_attribute(std::string name)
+        %code%{ if (THIS->attributes.find(name) != THIS->attributes.end()) RETVAL = THIS->attributes[name]; %};
+    
+    void set_attribute(std::string name, std::string value)
+        %code%{ THIS->attributes[name] = value; %};
+
+%{
+
+SV*
+ModelMaterial::attributes()
+    CODE:
+        HV* hv = newHV();
+        for (t_model_material_attributes::const_iterator attr = THIS->attributes.begin(); attr != THIS->attributes.end(); ++attr) {
+            (void)hv_store( hv, attr->first.c_str(), attr->first.length(), newSVpv(attr->second.c_str(), attr->second.length()), 0 );
+        }
+        RETVAL = (SV*)newRV_noinc((SV*)hv);
+    OUTPUT:
+        RETVAL
+%}
+
+};
+
+
+%name{Slic3r::Model::Object} class ModelObject {
+    ModelObject(Model* model, std::string input_file,
+        DynamicPrintConfig* config, t_layer_height_ranges layer_height_ranges,
+        Pointf* origin_translation)
+        %code%{
+            RETVAL = new ModelObject(model, input_file, *config,
+                layer_height_ranges, *origin_translation);
+        %};
+
+    ~ModelObject();
+
+    ModelVolumePtrs *volumes()
+        %code%{
+            if (THIS->volumes.empty()) {
+                XSRETURN_UNDEF;
+            }
+
+            RETVAL = &THIS->volumes;
+        %};
+
+    ModelInstancePtrs *instances()
+        %code%{
+            if (THIS->instances.empty()) {
+                XSRETURN_UNDEF;
+            }
+
+            RETVAL = &THIS->instances;
+        %};
+
+
+    void invalidate_bounding_box();
+
+    Ref<BoundingBoxf3> _bounding_box(BoundingBoxf3 *new_bbox = NULL)
+        %code{%
+            if (NULL != new_bbox) {
+                THIS->_bounding_box = *new_bbox;
+                THIS->_bounding_box_valid = true;
+            }
+
+            if (!THIS->_bounding_box_valid) {
+                XSRETURN_UNDEF;
+            }
+
+            RETVAL = &THIS->_bounding_box;
+        %};
+
+    %name{_add_volume} Ref<ModelVolume> add_volume(
+            t_model_material_id material_id, TriangleMesh* mesh, bool modifier)
+        %code%{ RETVAL = THIS->add_volume(material_id, *mesh, modifier); %};
+
+    void delete_volume(size_t idx);
+    void clear_volumes();
+
+    %name{_add_instance} Ref<ModelInstance> add_instance(
+            double rotation, double scaling_factor, std::vector<double> offset)
+        %code%{
+            RETVAL = THIS->add_instance(rotation, scaling_factor,
+                Pointf(offset[0], offset[1]));
+        %};
+    void delete_last_instance();
+    void clear_instances();
+
+    std::string input_file()
+        %code%{ RETVAL = THIS->input_file; %};
+    void set_input_file(std::string value)
+        %code%{ THIS->input_file = value; %};
+    Ref<DynamicPrintConfig> config()
+        %code%{ RETVAL = &THIS->config; %};
+
+    Ref<Model> model()
+        %code%{ RETVAL = THIS->model; %};
+
+    t_layer_height_ranges layer_height_ranges()
+        %code%{ RETVAL = THIS->layer_height_ranges; %};
+
+    Clone<Pointf> origin_translation()
+        %code%{ RETVAL = THIS->origin_translation; %};
+};
+
+
+%name{Slic3r::Model::Volume} class ModelVolume {
+    ~ModelVolume();
+
+    Ref<ModelObject> object()
+        %code%{ RETVAL = THIS->object; %};
+    
+    t_model_material_id material_id()
+        %code%{ RETVAL = THIS->material_id; %};
+    
+    Ref<TriangleMesh> mesh()
+        %code%{ RETVAL = &THIS->mesh; %};
+    
+    bool modifier()
+        %code%{ RETVAL = THIS->modifier; %};
+};
+
+
+%name{Slic3r::Model::Instance} class ModelInstance {
+    ~ModelInstance();
+
+    Ref<ModelObject> object()
+        %code%{ RETVAL = THIS->object; %};
+
+    double rotation()
+        %code%{ RETVAL = THIS->rotation; %};
+    double scaling_factor()
+        %code%{ RETVAL = THIS->scaling_factor; %};
+    Clone<Pointf> offset()
+        %code%{ RETVAL = THIS->offset; %};
+
+    void set_rotation(double val)
+        %code%{ THIS->rotation = val; %};
+    void set_scaling_factor(double val)
+        %code%{ THIS->scaling_factor = val; %};
+    void set_offset(Pointf *offset)
+        %code%{ THIS->offset = *offset; %};
+};
diff --git a/xs/xsp/my.map b/xs/xsp/my.map
index 897e3d0f1..239f7adaf 100644
--- a/xs/xsp/my.map
+++ b/xs/xsp/my.map
@@ -1,6 +1,12 @@
+coordf_t T_NV
+
 std::vector<Points::size_type>  T_STD_VECTOR_INT
 std::vector<size_t>  T_STD_VECTOR_INT
+
 t_config_option_key T_STD_STRING
+t_model_material_id T_STD_STRING
+t_layer_height_ranges   T_LAYER_HEIGHT_RANGES
+
 
 BoundingBox*               O_OBJECT_SLIC3R
 Ref<BoundingBox>           O_OBJECT_SLIC3R_T
@@ -11,6 +17,7 @@ Ref<BoundingBoxf3>         O_OBJECT_SLIC3R_T
 Clone<BoundingBoxf3>       O_OBJECT_SLIC3R_T
 
 DynamicPrintConfig*        O_OBJECT_SLIC3R
+Ref<DynamicPrintConfig>    O_OBJECT_SLIC3R_T
 PrintObjectConfig*         O_OBJECT_SLIC3R
 PrintRegionConfig*         O_OBJECT_SLIC3R
 PrintConfig*               O_OBJECT_SLIC3R
@@ -83,6 +90,27 @@ SurfaceCollection*         O_OBJECT_SLIC3R
 
 Extruder*                  O_OBJECT_SLIC3R
 
+Model*                     O_OBJECT_SLIC3R
+Ref<Model>                 O_OBJECT_SLIC3R_T
+Clone<Model>               O_OBJECT_SLIC3R_T
+
+ModelMaterial*             O_OBJECT_SLIC3R
+Ref<ModelMaterial>         O_OBJECT_SLIC3R_T
+Clone<ModelMaterial>       O_OBJECT_SLIC3R_T
+
+ModelObject*               O_OBJECT_SLIC3R
+Ref<ModelObject>           O_OBJECT_SLIC3R_T
+Clone<ModelObject>         O_OBJECT_SLIC3R_T
+
+ModelVolume*               O_OBJECT_SLIC3R
+Ref<ModelVolume>           O_OBJECT_SLIC3R_T
+Clone<ModelVolume>         O_OBJECT_SLIC3R_T
+
+ModelInstance*             O_OBJECT_SLIC3R
+Ref<ModelInstance>         O_OBJECT_SLIC3R_T
+Clone<ModelInstance>       O_OBJECT_SLIC3R_T
+
+
 ExtrusionRole     T_UV
 FlowRole     T_UV
 PrintStep     T_UV
@@ -104,12 +132,16 @@ Surfaces        T_ARRAYREF
 # by reference and marked ::Ref because they're contained in another
 # Perl object
 Polygons*       T_ARRAYREF_PTR
+ModelObjectPtrs* T_PTR_ARRAYREF_PTR
+ModelVolumePtrs* T_PTR_ARRAYREF_PTR
+ModelInstancePtrs*   T_PTR_ARRAYREF_PTR
 
 # we return these types whenever we want the items to be returned
 # by reference and not marked ::Ref because they're newly allocated
 # and not referenced by any Perl object
 TriangleMeshPtrs T_PTR_ARRAYREF
 
+
 INPUT
 
 O_OBJECT_SLIC3R
@@ -141,6 +173,53 @@ T_ARRAYREF
 	             ${$ALIAS?\q[GvNAME(CvGV(cv))]:\qq[\"$pname\"]},
 	             \"$var\");
 
+T_LAYER_HEIGHT_RANGES
+    {
+        if (!SvROK($arg) || SvTYPE(SvRV($arg)) != SVt_PVAV) {
+            Perl_croak(aTHX_ \"%s: %s is not an array reference\",
+                     ${$ALIAS?\q[GvNAME(CvGV(cv))]:\qq[\"$pname\"]},
+                     \"$var\");
+        }
+
+        AV* av = (AV*)SvRV($arg);
+        const unsigned int len = av_len(av)+1;
+        t_layer_height_ranges tmp_ranges;
+        for (unsigned int i = 0; i < len; i++) {
+            SV* elem = *av_fetch(av, i, 0);
+            if (!SvROK(elem) || SvTYPE(SvRV(elem)) != SVt_PVAV) {
+                Perl_croak(
+                    aTHX_ \"%s: %s contains something that is not an array reference\",
+                        ${$ALIAS?\q[GvNAME(CvGV(cv))]:\qq[\"$pname\"]},
+                        \"$var\");
+            }
+
+            AV* elemAV = (AV*)SvRV(elem);
+            if (av_len(elemAV) + 1 != 3) {
+                Perl_croak(
+                    aTHX_ \"%s: %s contains an array that isn't 3 elements long\",
+                        ${$ALIAS?\q[GvNAME(CvGV(cv))]:\qq[\"$pname\"]},
+                        \"$var\");
+            }
+
+            coordf_t vals[3];
+            for (unsigned int j = 0; j < 3; ++j) {
+                SV *elem_elem = *av_fetch(elemAV, j, 0);
+                if (!SvNOK(elem_elem)) {
+                    Perl_croak(
+                        aTHX_ \"%s: layer ranges and heights must be numbers\",
+                            ${$ALIAS?\q[GvNAME(CvGV(cv))]:\qq[\"$pname\"]});
+                }
+
+                vals[j] = SvNV(elem_elem);
+            }
+
+            tmp_ranges[t_layer_height_range(vals[0], vals[1])] = vals[2];
+        }
+
+        $var = tmp_ranges;
+    }
+
+
 OUTPUT
 # return object from pointer
 O_OBJECT_SLIC3R
@@ -172,6 +251,16 @@ T_ARRAYREF_PTR
         av_store(av, i++, it->to_SV_ref());
 	}
 
+T_PTR_ARRAYREF_PTR
+    AV* av = newAV();
+    $arg = newRV_noinc((SV*)av);
+    sv_2mortal($arg);
+    av_extend(av, $var->size()-1);
+    int i = 0;
+    for (${ my $t = $type; $t =~ s/\*$//; \$t }::iterator it = $var->begin(); it != $var->end(); ++it) {
+        av_store(av, i++, (*it)->to_SV_ref());
+    }
+
 T_PTR_ARRAYREF
     AV* av = newAV();
 	$arg = newRV_noinc((SV*)av);
@@ -181,3 +270,30 @@ T_PTR_ARRAYREF
     for (${type}::iterator it = $var.begin(); it != $var.end(); ++it) {
         av_store(av, i++, (*it)->to_SV());
 	}
+
+T_LAYER_HEIGHT_RANGES
+    AV* av = newAV();
+    $arg = newRV_noinc((SV*)av);
+    sv_2mortal($arg);
+    av_extend(av, $var.size() - 1);
+    // map is sorted, so we can just copy it in order
+    int i = 0;
+    for (${type}::iterator it = $var.begin(); it != $var.end(); ++it) {
+        const coordf_t range_values[] = {
+                it->first.first,    // key's first = minz
+                it->first.second,   // key's second = maxz
+                it->second,         // value = height
+            };
+
+        AV *rangeAV = newAV();
+        SV *rangeAV_ref = newRV_noinc((SV*)rangeAV);
+        sv_2mortal(rangeAV_ref);
+        av_extend(rangeAV, 2);
+        for (int j = 0; j < 3; ++j) {
+            SV *val = sv_newmortal();
+            sv_setnv(val, range_values[j]);
+            av_store(rangeAV, j, val);
+        }
+
+        av_store(av, i++, (SV*)rangeAV_ref);
+    }
diff --git a/xs/xsp/typemap.xspt b/xs/xsp/typemap.xspt
index 82e4f4d18..945b104bf 100644
--- a/xs/xsp/typemap.xspt
+++ b/xs/xsp/typemap.xspt
@@ -1,12 +1,16 @@
 %typemap{bool}{simple};
+%typemap{size_t}{simple};
+%typemap{coordf_t}{simple};
 %typemap{std::string};
 %typemap{t_config_option_key};
+%typemap{t_model_material_id};
 %typemap{std::vector<int>};
 %typemap{std::vector<size_t>};
 %typemap{std::vector<unsigned int>*};
 %typemap{std::vector<double>};
 %typemap{std::vector<double>*};
 %typemap{std::vector<std::string>};
+%typemap{t_layer_height_ranges};
 %typemap{SV*};
 %typemap{AV*};
 %typemap{Point*};
@@ -25,6 +29,7 @@
 %typemap{Ref<BoundingBoxf3>}{simple};
 %typemap{Clone<BoundingBoxf3>}{simple};
 %typemap{DynamicPrintConfig*};
+%typemap{Ref<DynamicPrintConfig>}{simple};
 %typemap{PrintObjectConfig*};
 %typemap{PrintRegionConfig*};
 %typemap{PrintConfig*};
@@ -73,8 +78,33 @@
 %typemap{ExtrusionPaths};
 %typemap{Surfaces};
 %typemap{Polygons*};
+%typemap{TriangleMesh*};
 %typemap{TriangleMeshPtrs};
 %typemap{Extruder*};
+%typemap{Model*};
+%typemap{Ref<Model>}{simple};
+%typemap{Clone<Model>}{simple};
+%typemap{ModelMaterial*};
+%typemap{Ref<ModelMaterial>}{simple};
+%typemap{Clone<ModelMaterial>}{simple};
+%typemap{ModelObject*};
+%typemap{Ref<ModelObject>}{simple};
+%typemap{Clone<ModelObject>}{simple};
+%typemap{ModelObjectPtrs*};
+%typemap{Ref<ModelObjectPtrs>}{simple};
+%typemap{Clone<ModelObjectPtrs>}{simple};
+%typemap{ModelVolume*};
+%typemap{Ref<ModelVolume>}{simple};
+%typemap{Clone<ModelVolume>}{simple};
+%typemap{ModelVolumePtrs*};
+%typemap{Ref<ModelVolumePtrs>}{simple};
+%typemap{Clone<ModelVolumePtrs>}{simple};
+%typemap{ModelInstance*};
+%typemap{Ref<ModelInstance>}{simple};
+%typemap{Clone<ModelInstance>}{simple};
+%typemap{ModelInstancePtrs*};
+%typemap{Ref<ModelInstancePtrs>}{simple};
+%typemap{Clone<ModelInstancePtrs>}{simple};
 
 %typemap{SurfaceType}{parsed}{
   %cpp_type{SurfaceType};