diff --git a/Build.PL b/Build.PL
index 513a26955..4ad56e18e 100644
--- a/Build.PL
+++ b/Build.PL
@@ -12,7 +12,7 @@ my $build = Module::Build->new(
         'File::Spec'                => '0',
         'Getopt::Long'              => '0',
         'Math::Clipper'             => '1.09',
-        'Math::ConvexHull'          => '1.0.4',
+        'Math::ConvexHull::MonotoneChain' => '0.01',
         'Math::Geometry::Voronoi'   => '1.3',
         'Math::PlanePath'           => '53',
         'Moo'                       => '0.091009',
diff --git a/lib/Slic3r.pm b/lib/Slic3r.pm
index e80357767..410e0b0b0 100644
--- a/lib/Slic3r.pm
+++ b/lib/Slic3r.pm
@@ -66,6 +66,7 @@ use constant SMALL_PERIMETER_LENGTH => (6.5 / SCALING_FACTOR) * 2 * PI;
 # them here because it makes accessing them slightly faster.
 our $Config;
 our $flow;
+our $first_layer_flow;
 
 sub parallelize {
     my %params = @_;
diff --git a/lib/Slic3r/ExtrusionPath.pm b/lib/Slic3r/ExtrusionPath.pm
index a006d8712..c5466bcf7 100644
--- a/lib/Slic3r/ExtrusionPath.pm
+++ b/lib/Slic3r/ExtrusionPath.pm
@@ -160,6 +160,7 @@ sub detect_arcs {
     
     $max_angle = deg2rad($max_angle || 15);
     $len_epsilon ||= 10 / &Slic3r::SCALING_FACTOR;
+    my $parallel_degrees_limit = abs(Slic3r::Geometry::deg2rad(3));
     
     my @points = @{$self->points};
     my @paths = ();
@@ -191,8 +192,8 @@ sub detect_arcs {
             $s3_angle += 2*PI if $s3_angle < 0;
             my $s1s2_angle = $s2_angle - $s1_angle;
             my $s2s3_angle = $s3_angle - $s2_angle;
-            next if abs($s1s2_angle - $s2s3_angle) > $Slic3r::Geometry::parallel_degrees_limit;
-            next if abs($s1s2_angle) < $Slic3r::Geometry::parallel_degrees_limit;     # ignore parallel lines
+            next if abs($s1s2_angle - $s2s3_angle) > $parallel_degrees_limit;
+            next if abs($s1s2_angle) < $parallel_degrees_limit;     # ignore parallel lines
             next if $s1s2_angle > $max_angle;  # ignore too sharp vertices
             my @arc_points = ($points[$i], $points[$i+3]),  # first and last points
             
@@ -205,7 +206,7 @@ sub detect_arcs {
                 my $line_angle = $line->atan;
                 $line_angle += 2*PI if $line_angle < 0;
                 my $anglediff = $line_angle - $last_line_angle;
-                last if abs($s1s2_angle - $anglediff) > $Slic3r::Geometry::parallel_degrees_limit;
+                last if abs($s1s2_angle - $anglediff) > $parallel_degrees_limit;
                 
                 # point $j+1 belongs to the arc
                 $arc_points[-1] = $points[$j+1];
diff --git a/lib/Slic3r/Fill/Concentric.pm b/lib/Slic3r/Fill/Concentric.pm
index 699b526d9..2a7c7823b 100644
--- a/lib/Slic3r/Fill/Concentric.pm
+++ b/lib/Slic3r/Fill/Concentric.pm
@@ -63,7 +63,7 @@ sub fill_surface {
         my $path = $loop->split_at_index($index);
         
         # clip the path to avoid the extruder to get exactly on the first point of the loop
-        $path->clip_end($self->layer ? $self->layer->flow->scaled_width : $Slic3r::flow->scaled_width * 0.15);
+        $path->clip_end(($self->layer ? $self->layer->flow->scaled_width : $Slic3r::flow->scaled_width) * 0.15);
         
         push @paths, $path->points if @{$path->points};
     }
diff --git a/lib/Slic3r/Fill/Honeycomb.pm b/lib/Slic3r/Fill/Honeycomb.pm
index 70dd1e2ad..66fbd7ebb 100644
--- a/lib/Slic3r/Fill/Honeycomb.pm
+++ b/lib/Slic3r/Fill/Honeycomb.pm
@@ -21,7 +21,7 @@ sub fill_surface {
     # infill math
     my $min_spacing = scale $params{flow_spacing};
     my $distance = $min_spacing / $params{density};
-    my $overlap_distance = $self->layer ? $self->layer->flow->scaled_width : $Slic3r::flow->scaled_width * 0.4;
+    my $overlap_distance = ($self->layer ? $self->layer->flow->scaled_width : $Slic3r::flow->scaled_width) * 0.4;
     
     my $cache_id = sprintf "d%s_s%s_a%s",
         $params{density}, $params{flow_spacing}, $rotate_vector->[0][0];
diff --git a/lib/Slic3r/Fill/Rectilinear.pm b/lib/Slic3r/Fill/Rectilinear.pm
index b4569dbc8..d13321015 100644
--- a/lib/Slic3r/Fill/Rectilinear.pm
+++ b/lib/Slic3r/Fill/Rectilinear.pm
@@ -31,7 +31,7 @@ sub fill_surface {
         $flow_spacing = unscale $distance_between_lines;
     }
     
-    my $overlap_distance = $self->layer ? $self->layer->flow->scaled_width : $Slic3r::flow->scaled_width * 0.4;
+    my $overlap_distance = ($self->layer ? $self->layer->flow->scaled_width : $Slic3r::flow->scaled_width) * 0.4;
     
     my $x = $bounding_box->[X1];
     my $is_line_pattern = $self->isa('Slic3r::Fill::Line');
diff --git a/lib/Slic3r/GCode.pm b/lib/Slic3r/GCode.pm
index a135be271..7653e4c32 100644
--- a/lib/Slic3r/GCode.pm
+++ b/lib/Slic3r/GCode.pm
@@ -421,7 +421,7 @@ sub set_temperature {
         : ('M104', 'set temperature');
     my $gcode = sprintf "$code %s%d %s; $comment\n",
         ($Slic3r::Config->gcode_flavor eq 'mach3' ? 'P' : 'S'), $temperature,
-        (defined $tool && $tool != $self->extruder->id) ? "T$tool " : "";
+        (defined $tool && $self->multiple_extruders) ? "T$tool " : "";
     
     $gcode .= "M116 ; wait for temperature to be reached\n"
         if $Slic3r::Config->gcode_flavor eq 'teacup' && $wait;
diff --git a/lib/Slic3r/GUI/Plater.pm b/lib/Slic3r/GUI/Plater.pm
index 37dd165fa..6d1f093c3 100644
--- a/lib/Slic3r/GUI/Plater.pm
+++ b/lib/Slic3r/GUI/Plater.pm
@@ -5,7 +5,7 @@ use utf8;
 
 use File::Basename qw(basename dirname);
 use List::Util qw(max sum);
-use Math::ConvexHull qw(convex_hull);
+use Math::ConvexHull::MonotoneChain qw(convex_hull);
 use Slic3r::Geometry qw(X Y Z X1 Y1 X2 Y2 MIN MAX);
 use Slic3r::Geometry::Clipper qw(JT_ROUND);
 use threads::shared qw(shared_clone);
@@ -301,7 +301,7 @@ sub load_file {
             name                    => basename($input_file),
             input_file              => $input_file,
             input_file_object_id    => $i,
-            mesh                    => $model->objects->[$i]->mesh,
+            model_object            => $model->objects->[$i],
             instances               => [
                 $model->objects->[$i]->instances
                     ? (map $_->offset, @{$model->objects->[$i]->instances})
@@ -384,6 +384,7 @@ sub decrease {
     my ($obj_idx, $object) = $self->selected_object;
     if ($object->instances_count >= 2) {
         pop @{$object->instances};
+        $self->{list}->SetItem($obj_idx, 1, $object->instances_count);
     } else {
         $self->remove;
     }
@@ -454,7 +455,14 @@ sub split_object {
     
     my ($obj_idx, $current_object) = $self->selected_object;
     my $current_copies_num = $current_object->instances_count;
-    my $mesh = $current_object->get_mesh;
+    my $model_object = $current_object->get_model_object;
+    
+    if (@{$model_object->volumes} > 1) {
+        Slic3r::GUI::warning_catcher($self)->("The selected object couldn't be splitted because it contains more than one volume/material.");
+        return;
+    }
+    
+    my $mesh = $model_object->mesh;
     $mesh->align_to_origin;
     
     my @new_meshes = $mesh->split_mesh;
@@ -668,20 +676,24 @@ sub make_model {
     my $self = shift;
     
     my $model = Slic3r::Model->new;
-    foreach my $object (@{$self->{objects}}) {
-        my $mesh = $object->get_mesh;
-        $mesh->scale($object->scale);
-        my $model_object = $model->add_object(
-            vertices    => $mesh->vertices,
-            input_file  => $object->input_file,
+    foreach my $plater_object (@{$self->{objects}}) {
+        my $model_object = $plater_object->get_model_object;
+        my $new_model_object = $model->add_object(
+            vertices    => $model_object->vertices,
+            input_file  => $plater_object->input_file,
         );
-        $model_object->add_volume(
-            facets      => $mesh->facets,
-        );
-        $model_object->add_instance(
-            rotation    => $object->rotate,
+        foreach my $volume (@{$model_object->volumes}) {
+            $new_model_object->add_volume(
+                material_id => $volume->material_id,
+                facets      => $volume->facets,
+            );
+            $model->materials->{$volume->material_id || 0} ||= {};
+        }
+        $new_model_object->scale($plater_object->scale);
+        $new_model_object->add_instance(
+            rotation    => $plater_object->rotate,
             offset      => [ @$_ ],
-        ) for @{$object->instances};
+        ) for @{$plater_object->instances};
     }
     
     return $model;
@@ -710,7 +722,7 @@ sub on_thumbnail_made {
     my $self = shift;
     my ($obj_idx) = @_;
     
-    $self->{objects}[$obj_idx]->free_mesh;
+    $self->{objects}[$obj_idx]->free_model_object;
     $self->recenter;
     $self->{canvas}->Refresh;
 }
@@ -1000,38 +1012,38 @@ sub OnDropFiles {
 package Slic3r::GUI::Plater::Object;
 use Moo;
 
-use Math::ConvexHull qw(convex_hull);
+use Math::ConvexHull::MonotoneChain qw(convex_hull);
 use Slic3r::Geometry qw(X Y);
 
 has 'name'                  => (is => 'rw', required => 1);
 has 'input_file'            => (is => 'rw', required => 1);
-has 'input_file_object_id'  => (is => 'rw');  # undef means keep mesh
-has 'mesh'                  => (is => 'rw', required => 1, trigger => 1);
+has 'input_file_object_id'  => (is => 'rw');  # undef means keep model object
+has 'model_object'          => (is => 'rw', required => 1, trigger => 1);
 has 'size'                  => (is => 'rw');
 has 'scale'                 => (is => 'rw', default => sub { 1 });
 has 'rotate'                => (is => 'rw', default => sub { 0 });
 has 'instances'             => (is => 'rw', default => sub { [] }); # upward Y axis
 has 'thumbnail'             => (is => 'rw');
 
-sub _trigger_mesh {
+sub _trigger_model_object {
     my $self = shift;
-    $self->size([$self->mesh->size]) if $self->mesh;
+    $self->size([$self->model_object->mesh->size]) if $self->model_object;
 }
 
-sub free_mesh {
+sub free_model_object {
     my $self = shift;
     
     # only delete mesh from memory if we can retrieve it from the original file
     return unless $self->input_file && $self->input_file_object_id;
-    $self->mesh(undef);
+    $self->model_object(undef);
 }
 
-sub get_mesh {
+sub get_model_object {
     my $self = shift;
     
-    return $self->mesh->clone if $self->mesh;
+    return $self->model_object if $self->model_object;
     my $model = Slic3r::Model->read_from_file($self->input_file);
-    return $model->objects->[$self->input_file_object_id]->mesh;
+    return $model->objects->[$self->input_file_object_id];
 }
 
 sub instances_count {
@@ -1043,7 +1055,7 @@ sub make_thumbnail {
     my $self = shift;
     my %params = @_;
     
-    my @points = map [ @$_[X,Y] ], @{$self->mesh->vertices};
+    my @points = map [ @$_[X,Y] ], @{$self->model_object->mesh->vertices};
     my $convex_hull = Slic3r::Polygon->new(convex_hull(\@points));
     for (@$convex_hull) {
         @$_ = map $_ * $params{scaling_factor}, @$_;
@@ -1054,7 +1066,7 @@ sub make_thumbnail {
     $convex_hull->align_to_origin;
     
     $self->thumbnail($convex_hull);  # ignored in multi-threaded environments
-    $self->mesh(undef) if defined $self->input_file_object_id;
+    $self->free_model_object;
     
     return $convex_hull;
 }
diff --git a/lib/Slic3r/GUI/Tab.pm b/lib/Slic3r/GUI/Tab.pm
index 69eab8820..0a6eacab8 100644
--- a/lib/Slic3r/GUI/Tab.pm
+++ b/lib/Slic3r/GUI/Tab.pm
@@ -85,6 +85,12 @@ sub new {
     });
     
     EVT_BUTTON($self, $self->{btn_save_preset}, sub {
+        
+        # since buttons (and choices too) don't get focus on Mac, we set focus manually
+        # to the treectrl so that the EVT_* events are fired for the input field having
+        # focus currently. is there anything better than this?
+        $self->{treectrl}->SetFocus;
+        
         my $preset = $self->current_preset;
         my $default_name = $preset->{default} ? 'Untitled' : basename($preset->{name});
         $default_name =~ s/\.ini$//i;
diff --git a/lib/Slic3r/Geometry.pm b/lib/Slic3r/Geometry.pm
index b5bec3a8d..c89faaf6f 100644
--- a/lib/Slic3r/Geometry.pm
+++ b/lib/Slic3r/Geometry.pm
@@ -36,7 +36,7 @@ use constant X2 => 2;
 use constant Y2 => 3;
 use constant MIN => 0;
 use constant MAX => 1;
-our $parallel_degrees_limit = abs(deg2rad(3));
+our $parallel_degrees_limit = abs(deg2rad(0.1));
 
 sub epsilon () { 1E-4 }
 sub scaled_epsilon () { epsilon / &Slic3r::SCALING_FACTOR }
diff --git a/lib/Slic3r/Geometry/Clipper.pm b/lib/Slic3r/Geometry/Clipper.pm
index 5a1dfdd91..fca00af57 100644
--- a/lib/Slic3r/Geometry/Clipper.pm
+++ b/lib/Slic3r/Geometry/Clipper.pm
@@ -14,12 +14,12 @@ our $clipper = Math::Clipper->new;
 
 sub safety_offset {
     my ($polygons, $factor) = @_;
-    return Math::Clipper::offset($polygons, $factor || (scale 1e-05), 100, JT_MITER, 2);
+    return Math::Clipper::offset($polygons, $factor || (scale 1e-05), 100000, JT_MITER, 2);
 }
 
 sub offset {
     my ($polygons, $distance, $scale, $joinType, $miterLimit) = @_;
-    $scale      ||= &Slic3r::SCALING_FACTOR * 1000000;
+    $scale      ||= 100000;
     $joinType   = JT_MITER if !defined $joinType;
     $miterLimit ||= 2;
     
diff --git a/lib/Slic3r/Layer/Region.pm b/lib/Slic3r/Layer/Region.pm
index a25ef993f..e6cbff4c4 100644
--- a/lib/Slic3r/Layer/Region.pm
+++ b/lib/Slic3r/Layer/Region.pm
@@ -358,7 +358,7 @@ sub prepare_fill_surfaces {
             
             # offset inwards
             my @offsets = $surface->expolygon->offset_ex(-$distance);
-            @offsets = @{union_ex(Math::Clipper::offset([ map @$_, @offsets ], $distance, 100, JT_MITER))};
+            @offsets = @{union_ex(Math::Clipper::offset([ map @$_, @offsets ], $distance, 100000, JT_MITER))};
             map Slic3r::Surface->new(
                 expolygon => $_,
                 surface_type => $surface->surface_type,
diff --git a/lib/Slic3r/Model.pm b/lib/Slic3r/Model.pm
index 1e2a6b2ba..ffc5ab901 100644
--- a/lib/Slic3r/Model.pm
+++ b/lib/Slic3r/Model.pm
@@ -37,6 +37,12 @@ sub set_material {
     );
 }
 
+sub scale {
+    my $self = shift;
+    
+    $_->scale(@_) for @{$self->objects};
+}
+
 # flattens everything to a single mesh
 sub mesh {
     my $self = shift;
@@ -112,6 +118,17 @@ sub mesh {
     );
 }
 
+sub scale {
+    my $self = shift;
+    my ($factor) = @_;
+    return if $factor == 1;
+    
+    # transform vertex coordinates
+    foreach my $vertex (@{$self->vertices}) {
+        $vertex->[$_] *= $factor for X,Y,Z;
+    }
+}
+
 package Slic3r::Model::Volume;
 use Moo;
 
diff --git a/lib/Slic3r/Print.pm b/lib/Slic3r/Print.pm
index 9231fa9cc..3669187b2 100644
--- a/lib/Slic3r/Print.pm
+++ b/lib/Slic3r/Print.pm
@@ -4,7 +4,7 @@ use Moo;
 use File::Basename qw(basename fileparse);
 use File::Spec;
 use List::Util qw(max);
-use Math::ConvexHull 1.0.4 qw(convex_hull);
+use Math::ConvexHull::MonotoneChain qw(convex_hull);
 use Slic3r::ExtrusionPath ':roles';
 use Slic3r::Geometry qw(X Y Z X1 Y1 X2 Y2 MIN PI scale unscale move_points nearest_point);
 use Slic3r::Geometry::Clipper qw(diff_ex union_ex intersection_ex offset JT_ROUND JT_SQUARE);
@@ -185,8 +185,16 @@ sub init_extruders {
         );
     }
     
+    # calculate default flows
+    $Slic3r::flow = $self->extruders->[0]->make_flow(
+        width           => $self->config->extrusion_width,
+    );
+    $Slic3r::first_layer_flow = $self->extruders->[0]->make_flow(
+        layer_height    => $self->config->get_value('first_layer_height'),
+        width           => $self->config->first_layer_extrusion_width,
+    );
+    
     # calculate regions' flows
-    $Slic3r::flow = $self->extruders->[0]->make_flow(width => $self->config->extrusion_width);
     for my $region_id (0 .. $#{$self->regions}) {
         my $region = $self->regions->[$region_id];
         
@@ -421,7 +429,7 @@ sub export_gcode {
     # make skirt
     $status_cb->(88, "Generating skirt");
     $self->make_skirt;
-    $self->make_brim;
+    $self->make_brim;  # must come after make_skirt
     
     # output everything to a G-code file
     my $output_file = $self->expanded_output_filepath($params{output_file});
@@ -559,25 +567,22 @@ sub make_skirt {
     my $convex_hull = convex_hull(\@points);
     
     # draw outlines from outside to inside
-    my $flow = $Slic3r::first_layer_flow || $Slic3r::flow;
-    my @skirt = ();
     for (my $i = $Slic3r::Config->skirts; $i > 0; $i--) {
-        my $distance = scale ($Slic3r::Config->skirt_distance + ($flow->spacing * $i));
+        my $distance = scale ($Slic3r::Config->skirt_distance + ($Slic3r::first_layer_flow->spacing * $i));
         my $outline = Math::Clipper::offset([$convex_hull], $distance, &Slic3r::SCALING_FACTOR * 100, JT_ROUND);
-        push @skirt, Slic3r::ExtrusionLoop->pack(
-            polygon => Slic3r::Polygon->new(@{$outline->[0]}),
-            role => EXTR_ROLE_SKIRT,
+        push @{$self->skirt}, Slic3r::ExtrusionLoop->pack(
+            polygon         => Slic3r::Polygon->new(@{$outline->[0]}),
+            role            => EXTR_ROLE_SKIRT,
+            flow_spacing    => $Slic3r::first_layer_flow->spacing,
         );
     }
-    unshift @{$self->skirt}, @skirt;
 }
 
 sub make_brim {
     my $self = shift;
     return unless $Slic3r::Config->brim_width > 0;
     
-    my $flow = $Slic3r::first_layer_flow || $Slic3r::flow;
-    my $grow_distance = $flow->scaled_width / 2;
+    my $grow_distance = $Slic3r::first_layer_flow->scaled_width / 2;
     my @islands = (); # array of polygons
     foreach my $obj_idx (0 .. $#{$self->objects}) {
         my $layer0 = $self->objects->[$obj_idx]->layers->[0];
@@ -591,13 +596,19 @@ sub make_brim {
         }
     }
     
-    my $num_loops = sprintf "%.0f", $Slic3r::Config->brim_width / $flow->width;
+    # if brim touches skirt, make it around skirt too
+    if ($Slic3r::Config->skirt_distance + (($Slic3r::Config->skirts - 1) * $Slic3r::first_layer_flow->spacing) <= $Slic3r::Config->brim_width) {
+        push @islands, map $_->unpack->split_at_first_point->polyline->grow($grow_distance), @{$self->skirt};
+    }
+    
+    my $num_loops = sprintf "%.0f", $Slic3r::Config->brim_width / $Slic3r::first_layer_flow->width;
     for my $i (reverse 1 .. $num_loops) {
         # JT_SQUARE ensures no vertex is outside the given offset distance
         push @{$self->brim}, Slic3r::ExtrusionLoop->pack(
-            polygon => Slic3r::Polygon->new($_),
-            role    => EXTR_ROLE_SKIRT,
-        ) for @{Math::Clipper::offset(\@islands, $i * $flow->scaled_spacing, 100, JT_SQUARE)};
+            polygon         => Slic3r::Polygon->new($_),
+            role            => EXTR_ROLE_SKIRT,
+            flow_spacing    => $Slic3r::first_layer_flow->spacing,
+        ) for @{Math::Clipper::offset(\@islands, $i * $Slic3r::first_layer_flow->scaled_spacing, 100, JT_SQUARE)};
         # TODO: we need the offset inwards/offset outwards logic to avoid overlapping extrusions
     }
 }
@@ -699,7 +710,7 @@ sub write_gcode {
             $gcodegen->shift_y($shift[Y]);
             $gcode .= $gcodegen->set_acceleration($Slic3r::Config->perimeter_acceleration);
             # skip skirt if we have a large brim
-            if ($layer_id < $Slic3r::Config->skirt_height && ($layer_id != 0 || $Slic3r::Config->skirt_distance + (($Slic3r::Config->skirts - 1) * $Slic3r::flow->spacing) > $Slic3r::Config->brim_width)) {
+            if ($layer_id < $Slic3r::Config->skirt_height) {
                 $gcode .= $gcodegen->extrude_loop($_, 'skirt') for @{$self->skirt};
             }
             $skirt_done++;
diff --git a/lib/Slic3r/Print/Object.pm b/lib/Slic3r/Print/Object.pm
index ccb9723ff..3d7066a34 100644
--- a/lib/Slic3r/Print/Object.pm
+++ b/lib/Slic3r/Print/Object.pm
@@ -2,7 +2,7 @@ package Slic3r::Print::Object;
 use Moo;
 
 use Slic3r::ExtrusionPath ':roles';
-use Slic3r::Geometry qw(scale unscale deg2rad);
+use Slic3r::Geometry qw(scale unscale deg2rad scaled_epsilon);
 use Slic3r::Geometry::Clipper qw(diff_ex intersection_ex union_ex);
 use Slic3r::Surface ':types';
 
@@ -211,7 +211,7 @@ sub make_perimeters {
                         # of our slice
                         my $hypothetical_perimeter;
                         {
-                            my $outer = [ map @$_, $slice->expolygon->offset_ex(- ($hypothetical_perimeter_num-1.5) * $perimeter_flow->scaled_spacing) ];
+                            my $outer = [ map @$_, $slice->expolygon->offset_ex(- ($hypothetical_perimeter_num-1.5) * $perimeter_flow->scaled_spacing - scaled_epsilon) ];
                             last CYCLE if !@$outer;
                             my $inner = [ map @$_, $slice->expolygon->offset_ex(- ($hypothetical_perimeter_num-0.5) * $perimeter_flow->scaled_spacing) ];
                             last CYCLE if !@$inner;
diff --git a/utils/file_info.pl b/utils/file_info.pl
index 36e57e9b0..e8eb09456 100755
--- a/utils/file_info.pl
+++ b/utils/file_info.pl
@@ -25,12 +25,14 @@ my %opt = ();
 
 {
     my $input_file = $ARGV[0];
-    my $mesh;
-    $mesh = Slic3r::Format::STL->read_file($input_file) if $input_file =~ /\.stl$/i;
     die "This script doesn't support AMF yet\n" if $input_file =~ /\.amf$/i;
-    die "Unable to read file\n" if !$mesh;
+    
+    my $model;
+    $model = Slic3r::Format::STL->read_file($input_file) if $input_file =~ /\.stl$/i;
+    die "Unable to read file\n" if !$model;
     
     printf "Info about %s:\n", basename($input_file);
+    my $mesh = $model->mesh;
     $mesh->check_manifoldness;
     printf "  number of facets: %d\n", scalar @{$mesh->facets};
     printf "  size: x=%s y=%s z=%s\n", $mesh->size;