diff --git a/lib/Slic3r.pm b/lib/Slic3r.pm
index ecba7ba8a..e2e7c50dd 100644
--- a/lib/Slic3r.pm
+++ b/lib/Slic3r.pm
@@ -226,6 +226,7 @@ sub thread_cleanup {
     *Slic3r::Geometry::BoundingBoxf::DESTROY = sub {};
     *Slic3r::Geometry::BoundingBoxf3::DESTROY = sub {};
     *Slic3r::Layer::PerimeterGenerator::DESTROY = sub {};
+    *Slic3r::LayerHeightSpline::DESTROY     = sub {};
     *Slic3r::Line::DESTROY                  = sub {};
     *Slic3r::Linef3::DESTROY                = sub {};
     *Slic3r::Model::DESTROY                 = sub {};
diff --git a/lib/Slic3r/GUI/Plater/SplineControl.pm b/lib/Slic3r/GUI/Plater/SplineControl.pm
index 8f1d7e5fe..236b68903 100644
--- a/lib/Slic3r/GUI/Plater/SplineControl.pm
+++ b/lib/Slic3r/GUI/Plater/SplineControl.pm
@@ -79,33 +79,74 @@ sub repaint {
     # draw original layers as lines
     my $last_z = 0.0;
     my @points = ();
-    foreach my $z (@{$self->{original_interpolated_layers}}) {
-        my $layer_h = $z - $last_z;
+#    foreach my $z (@{$self->{original_interpolated_layers}}) {
+#        my $layer_h = $z - $last_z;
+#        $dc->SetPen($self->{original_pen});
+#        my $pl = $self->point_to_pixel(0, $z);
+#        my $pr = $self->point_to_pixel($layer_h, $z);
+#        #$dc->DrawLine($pl->x, $pl->y, $pr->x, $pr->y);
+#        push (@points, $pr);
+#        $last_z = $z;
+#    }
+#
+#    $dc->DrawSpline(\@points);
+    if($self->{original_height_spline}) {
+        $last_z = 0.0;
+        @points = ();
+        #draw spline
         $dc->SetPen($self->{original_pen});
-        my $pl = $self->point_to_pixel(0, $z);
-        my $pr = $self->point_to_pixel($layer_h, $z);
-        #$dc->DrawLine($pl->x, $pl->y, $pr->x, $pr->y);
-        push (@points, $pr);
-        $last_z = $z;
+        @points = ();
+        foreach my $pixel (0..$size[1]) {
+            my @z = $self->pixel_to_point(Wx::Point->new(0, $pixel));
+            my $h = $self->{original_height_spline}->getLayerHeightAt($z[1]);
+            my $p = $self->point_to_pixel($h, $z[1]);
+            push (@points, $p);
+        }
+        $dc->DrawLines(\@points);
     }
-
-    $dc->DrawSpline(\@points);       
+    
+           
     
 #    # draw interactive (user modified) layers as lines
-    $last_z = 0.0;
-    @points = ();
-    if($self->{interactive_heights}) {
-    	foreach my $i (0..@{$self->{interactive_heights}}-1) {
-	        my $z = $self->{original_layers}[$i];
-	        my $layer_h = $self->{interactive_heights}[$i];
-	        $dc->SetPen($self->{interactive_pen});
-	        my $pl = $self->point_to_pixel(0, $z);
-	        my $pr = $self->point_to_pixel($layer_h, $z);
-	        $dc->DrawLine($pl->x, $pl->y, $pr->x, $pr->y);
-	        push (@points, $pr);
+#    $last_z = 0.0;
+#    @points = ();
+#    if($self->{interactive_heights}) {
+#    	foreach my $i (0..@{$self->{interactive_heights}}-1) {
+#	        my $z = $self->{original_layers}[$i];
+#	        my $layer_h = $self->{interactive_heights}[$i];
+#	        $dc->SetPen($self->{interactive_pen});
+#	        my $pl = $self->point_to_pixel(0, $z);
+#	        my $pr = $self->point_to_pixel($layer_h, $z);
+#	        $dc->DrawLine($pl->x, $pl->y, $pr->x, $pr->y);
+#	        push (@points, $pr);
+#	    }
+#	
+#	    $dc->DrawSpline(\@points);
+#    }
+    
+    if($self->{interactive_height_spline}) {
+    	$last_z = 0.0;
+        @points = ();
+        # draw layer lines
+        foreach my $z (@{$self->{interactive_height_spline}->getInterpolatedLayers}) {
+            my $layer_h = $z - $last_z;
+            $dc->SetPen($self->{interactive_pen});
+            my $pl = $self->point_to_pixel(0, $z);
+            my $pr = $self->point_to_pixel($layer_h, $z);
+            $dc->DrawLine($pl->x, $pl->y, $pr->x, $pr->y);
+            $last_z = $z;
+        }
+    	
+    	#draw spline
+    	$dc->SetPen($self->{interactive_pen});
+	    @points = ();
+	    foreach my $pixel (0..$size[1]) {
+	        my @z = $self->pixel_to_point(Wx::Point->new(0, $pixel));
+	        my $h = $self->{interactive_height_spline}->getLayerHeightAt($z[1]);
+	        my $p = $self->point_to_pixel($h, $z[1]);
+	        push (@points, $p);
 	    }
-	
-	    $dc->DrawSpline(\@points);
+	    $dc->DrawLines(\@points);
     }
 
  
@@ -152,10 +193,12 @@ sub mouse_event {
     	if ($event->LeftDown) {
            # start dragging
            $self->{left_drag_start_pos} = $pos;
+           $self->{interactive_height_spline} = $self->{object}->layer_height_spline->clone;
         }
         if ($event->RightDown) {
            # start dragging
            $self->{right_drag_start_pos} = $pos;
+           $self->{interactive_height_spline} = $self->{object}->layer_height_spline->clone;
         }
     } elsif ($event->LeftUp) {
         if($self->{left_drag_start_pos}) {
@@ -171,6 +214,7 @@ sub mouse_event {
     		$self->Refresh;
     		$self->{object}->layer_height_spline->suppressUpdate;
     		$self->{on_layer_update}->(@{$self->{interpolated_layers}});
+    		$self->{interactive_height_spline} = undef;
     	}
         $self->{left_drag_start_pos} = undef;
     } elsif ($event->RightUp) {
@@ -187,6 +231,7 @@ sub mouse_event {
             $self->Refresh;
             $self->{object}->layer_height_spline->suppressUpdate;
             $self->{on_layer_update}->(@{$self->{interpolated_layers}});
+            $self->{interactive_height_spline} = undef;
         }
         $self->{right_drag_start_pos} = undef;
     } elsif ($event->Dragging) {
@@ -197,6 +242,10 @@ sub mouse_event {
 
 	        # compute updated interactive layer heights
 	        $self->_interactive_quadratic_curve($start_pos[1], $obj_pos[0], $range);
+
+	        unless($self->{interactive_height_spline}->updateLayerHeights($self->{interactive_heights})) {
+	        	die "Unable to update interactive interpolated layers!\n";
+	        }
 	        $self->Refresh;
         } elsif($self->{right_drag_start_pos}) {
             my @start_pos = $self->pixel_to_point($self->{right_drag_start_pos});
@@ -204,6 +253,9 @@ sub mouse_event {
 
             # compute updated interactive layer heights
             $self->_interactive_linear_curve($start_pos[1], $obj_pos[0], $range);
+            unless($self->{interactive_height_spline}->updateLayerHeights($self->{interactive_heights})) {
+                die "Unable to update interactive interpolated layers!\n";
+            }
             $self->Refresh;
         }
     } elsif ($event->Moving) {
@@ -236,6 +288,7 @@ sub update {
 	my $self = shift;
 
     if($self->{object}->layer_height_spline->layersUpdated) {
+    	$self->{original_height_spline} = $self->{object}->layer_height_spline->clone;
 	    $self->{original_layers} = $self->{object}->layer_height_spline->getOriginalLayers;
 	    $self->{original_interpolated_layers} = $self->{object}->layer_height_spline->getInterpolatedLayers;
 	    $self->{interpolated_layers} = $self->{object}->layer_height_spline->getInterpolatedLayers; # Initialize to current values
diff --git a/xs/src/libslic3r/LayerHeightSpline.cpp b/xs/src/libslic3r/LayerHeightSpline.cpp
index c04cf2ce7..596a40932 100644
--- a/xs/src/libslic3r/LayerHeightSpline.cpp
+++ b/xs/src/libslic3r/LayerHeightSpline.cpp
@@ -21,6 +21,23 @@ LayerHeightSpline::LayerHeightSpline(coordf_t object_height)
 	this->_cusp_value = -1;
 }
 
+LayerHeightSpline::LayerHeightSpline(const LayerHeightSpline &other)
+:   _object_height(other._object_height), _layer_height_spline(NULL)
+{
+
+    this->_original_layers = other._original_layers;
+    this->_internal_layers = other._internal_layers;
+    this->_internal_layer_heights = other._internal_layer_heights;
+	this->_is_valid = other._is_valid;
+	this->_update_required = other._update_required;
+	this->_layers_updated = other._layers_updated;
+	this->_layer_heights_updated = other._layer_heights_updated;
+	this->_cusp_value = other._cusp_value;
+	if(this->_is_valid) {
+		this->_updateBSpline();
+	}
+}
+
 LayerHeightSpline::~LayerHeightSpline()
 {
     if (this->_layer_height_spline) {
@@ -80,9 +97,9 @@ bool LayerHeightSpline::setLayers(std::vector<coordf_t> layers)
 	// add 0-values at both ends to achieve correct boundary conditions
 	this->_internal_layers = this->_original_layers;
 	this->_internal_layers.insert(this->_internal_layers.begin(), 0); // add z = 0 to the front
-	this->_internal_layers.push_back(this->_internal_layers.back()+1); // and object_height + 1 to the end
-	this->_internal_layer_heights.insert(this->_internal_layer_heights.begin(), 0);
-	this->_internal_layer_heights.push_back(0);
+	//this->_internal_layers.push_back(this->_internal_layers.back()+1); // and object_height + 1 to the end
+	this->_internal_layer_heights.insert(this->_internal_layer_heights.begin(), this->_internal_layer_heights[0]);
+	//this->_internal_layer_heights.push_back(0);
 
 	this->_layers_updated = true;
 	this->_layer_heights_updated = false;
@@ -102,12 +119,14 @@ bool LayerHeightSpline::updateLayerHeights(std::vector<coordf_t> heights)
 	bool result = false;
 
 	// do we receive the correct number of values?
-	if(heights.size() == this->_internal_layers.size()-2) {
+	if(heights.size() == this->_internal_layers.size()-1) {
 		this->_internal_layer_heights = heights;
-		// add leading an trailing 0-value
-		this->_internal_layer_heights.insert(this->_internal_layer_heights.begin(), 0);
-		this->_internal_layer_heights.push_back(0);
+		// add leading and trailing 0-value
+		this->_internal_layer_heights.insert(this->_internal_layer_heights.begin(), this->_internal_layer_heights[0]);
+		//this->_internal_layer_heights.push_back(0);
 		result = this->_updateBSpline();
+	}else{
+		std::cerr << "Unable to update layer heights. You provided " << heights.size() << " layers, but " << this->_internal_layers.size()-1 << " expected" << std::endl;
 	}
 
 	this->_layers_updated = false;
@@ -186,7 +205,7 @@ bool LayerHeightSpline::_updateBSpline()
 			this->_internal_layers.size(),
             &this->_internal_layer_heights[0],
             0,
-            0,
+            1,
             0);
 
 	if (this->_layer_height_spline->ok()) {
diff --git a/xs/src/libslic3r/LayerHeightSpline.hpp b/xs/src/libslic3r/LayerHeightSpline.hpp
index 0b618a5ac..3fe9c09a4 100644
--- a/xs/src/libslic3r/LayerHeightSpline.hpp
+++ b/xs/src/libslic3r/LayerHeightSpline.hpp
@@ -12,6 +12,7 @@ class LayerHeightSpline
 {
     public:
     LayerHeightSpline(coordf_t object_height);
+    LayerHeightSpline(const LayerHeightSpline &other);
     ~LayerHeightSpline();
     bool hasData(); // indicate that we have valid data
     bool updateRequired(); // indicate whether we want to generate a new spline from the layers
diff --git a/xs/xsp/LayerHeightSpline.xsp b/xs/xsp/LayerHeightSpline.xsp
index 3f915230e..a7b33608f 100644
--- a/xs/xsp/LayerHeightSpline.xsp
+++ b/xs/xsp/LayerHeightSpline.xsp
@@ -6,7 +6,10 @@
 %}
 
 %name{Slic3r::LayerHeightSpline} class LayerHeightSpline {
-    // owned by PrintObject, no constructor/destructor
+    LayerHeightSpline(double object_height);
+    ~LayerHeightSpline();
+    Clone<LayerHeightSpline> clone()
+        %code%{ RETVAL = THIS; %};
     
     bool hasData();
     bool updateRequired();
@@ -21,7 +24,6 @@
     std::vector<double> getOriginalLayers();
     std::vector<double> getInterpolatedLayers();
     coordf_t getLayerHeightAt(coordf_t height);
-        //%code%{ RETVAL = THIS->upper_layer; %};
         
     void setCuspValue(coordf_t cusp_value);
     coordf_t getCuspValue();
diff --git a/xs/xsp/my.map b/xs/xsp/my.map
index 69c1831cc..66fa26e78 100644
--- a/xs/xsp/my.map
+++ b/xs/xsp/my.map
@@ -180,6 +180,7 @@ Ref<SupportLayer>          O_OBJECT_SLIC3R_T
 
 LayerHeightSpline*         O_OBJECT_SLIC3R
 Ref<LayerHeightSpline>     O_OBJECT_SLIC3R_T
+Clone<LayerHeightSpline>   O_OBJECT_SLIC3R_T
 
 PlaceholderParser*         O_OBJECT_SLIC3R
 Ref<PlaceholderParser>     O_OBJECT_SLIC3R_T
diff --git a/xs/xsp/typemap.xspt b/xs/xsp/typemap.xspt
index fbc2d03f5..7df7dfaf2 100644
--- a/xs/xsp/typemap.xspt
+++ b/xs/xsp/typemap.xspt
@@ -135,6 +135,7 @@
 
 %typemap{LayerHeightSpline*};
 %typemap{Ref<LayerHeightSpline>}{simple};
+%typemap{Clone<LayerHeightSpline>}{simple};
 
 %typemap{SupportLayer*};
 %typemap{Ref<SupportLayer>}{simple};