diff --git a/lib/Slic3r/GUI.pm b/lib/Slic3r/GUI.pm
index 6df7343c2..a6b946f9e 100644
--- a/lib/Slic3r/GUI.pm
+++ b/lib/Slic3r/GUI.pm
@@ -25,7 +25,6 @@ use Slic3r::GUI::Plater::3D;
 use Slic3r::GUI::Plater::3DPreview;
 use Slic3r::GUI::Plater::ObjectPartsPanel;
 use Slic3r::GUI::Plater::ObjectCutDialog;
-use Slic3r::GUI::Plater::ObjectLayersDialog;
 use Slic3r::GUI::Plater::ObjectSettingsDialog;
 use Slic3r::GUI::Plater::LambdaObjectDialog;
 use Slic3r::GUI::Plater::OverrideSettingsPanel;
diff --git a/lib/Slic3r/GUI/Plater.pm b/lib/Slic3r/GUI/Plater.pm
index ef1409938..561634cd8 100644
--- a/lib/Slic3r/GUI/Plater.pm
+++ b/lib/Slic3r/GUI/Plater.pm
@@ -172,7 +172,7 @@ sub new {
         $self->{htoolbar}->AddTool(TB_CUT, "Cut…", Wx::Bitmap->new($Slic3r::var->("package.png"), wxBITMAP_TYPE_PNG), '');
         $self->{htoolbar}->AddSeparator;
         $self->{htoolbar}->AddTool(TB_SETTINGS, "Settings…", Wx::Bitmap->new($Slic3r::var->("cog.png"), wxBITMAP_TYPE_PNG), '');
-        $self->{htoolbar}->AddTool(TB_LAYERS, "Layer heights…", Wx::Bitmap->new($Slic3r::var->("layers.png"), wxBITMAP_TYPE_PNG), '');
+        $self->{htoolbar}->AddTool(TB_LAYERS, "Layer heights…", Wx::Bitmap->new($Slic3r::var->("variable_layer_height.png"), wxBITMAP_TYPE_PNG), '');
     } else {
         my %tbar_buttons = (
             add             => "Add…",
@@ -1386,7 +1386,7 @@ sub async_apply_config {
     # reset preview canvases (invalidated contents will be hidden)
     $self->{toolpaths2D}->reload_print if $self->{toolpaths2D};
     $self->{preview3D}->reload_print if $self->{preview3D};
-    $self->{ObjectLayersDialog}->reload_preview if $self->{ObjectLayersDialog};
+    $self->{AdaptiveLayersDialog}->reload_preview if $self->{AdaptiveLayersDialog};
     
     if ($invalidated) {
         if (!$Slic3r::GUI::Settings->{_}{background_processing}) {
@@ -1463,7 +1463,7 @@ sub stop_background_process {
     
     $self->{toolpaths2D}->reload_print if $self->{toolpaths2D};
     $self->{preview3D}->reload_print if $self->{preview3D};
-    $self->{ObjectLayersDialog}->reload_preview if $self->{ObjectLayersDialog};
+    $self->{AdaptiveLayersDialog}->reload_preview if $self->{AdaptiveLayersDialog};
     
     if ($self->{process_thread}) {
         Slic3r::debugf "Killing background process.\n";
@@ -1610,7 +1610,7 @@ sub on_process_completed {
     return if $error;
     $self->{toolpaths2D}->reload_print if $self->{toolpaths2D};
     $self->{preview3D}->reload_print if $self->{preview3D};
-    $self->{ObjectLayersDialog}->reload_preview if $self->{ObjectLayersDialog};
+    $self->{AdaptiveLayersDialog}->reload_preview if $self->{AdaptiveLayersDialog};
     
     # if we have an export filename, start a new thread for exporting G-code
     if ($self->{export_gcode_output_file}) {
@@ -2108,32 +2108,12 @@ sub object_layers_dialog {
     my $self = shift;
     my ($obj_idx) = @_;
 
-    if (!defined $obj_idx) {
-        ($obj_idx, undef) = $self->selected_object;
-    }
-
-    if (!$Slic3r::GUI::have_OpenGL) {
-        Slic3r::GUI::show_error($self, "Please install the OpenGL modules to use this feature (see build instructions).");
-        return;
-    }
-
-    $self->{ObjectLayersDialog} = Slic3r::GUI::Plater::ObjectLayersDialog->new($self,
-		object              => $self->{objects}[$obj_idx],
-		model_object        => $self->{model}->objects->[$obj_idx],
-		obj_idx             => $obj_idx,
-	);
-	$self->{ObjectLayersDialog}->Show();
-	
-	EVT_CLOSE($self->{ObjectLayersDialog}, sub {
-        my ($dlg, $event) = @_;
-        $dlg->Destroy;
-        $self->{ObjectLayersDialog} = undef;
-    });
+    $self->object_settings_dialog($obj_idx, adaptive_layers => 1);
 }
 
 sub object_settings_dialog {
     my $self = shift;
-    my ($obj_idx) = @_;
+    my ($obj_idx, %params) = @_;
     
     if (!defined $obj_idx) {
         ($obj_idx, undef) = $self->selected_object;
@@ -2148,9 +2128,15 @@ sub object_settings_dialog {
     my $dlg = Slic3r::GUI::Plater::ObjectSettingsDialog->new($self,
 		object          => $self->{objects}[$obj_idx],
 		model_object    => $model_object,
+		obj_idx         => $obj_idx,
 	);
+	# store pointer to the adaptive layer tab to push preview updates
+	$self->{AdaptiveLayersDialog} = $dlg->{adaptive_layers};
+	# and jump directly to the tab if called by "promo-button"
+	$dlg->{tabpanel}->SetSelection(1) if $params{adaptive_layers};
 	$self->pause_background_process;
 	$dlg->ShowModal;
+	$self->{AdaptiveLayersDialog} = undef;
 	
     # update thumbnail since parts may have changed
     if ($dlg->PartsChanged) {
diff --git a/lib/Slic3r/GUI/Plater/ObjectLayersDialog.pm b/lib/Slic3r/GUI/Plater/ObjectLayersDialog.pm
deleted file mode 100644
index e81204a7b..000000000
--- a/lib/Slic3r/GUI/Plater/ObjectLayersDialog.pm
+++ /dev/null
@@ -1,150 +0,0 @@
-package Slic3r::GUI::Plater::ObjectLayersDialog;
-use strict;
-use warnings;
-use utf8;
-
-use Slic3r::Geometry qw(PI X Y Z scale unscale);
-use Slic3r::Print::State ':steps';
-use List::Util qw(min max sum first);
-use Wx qw(wxTheApp :dialog :id :misc :sizer :slider :statictext wxTAB_TRAVERSAL);
-use Wx::Event qw(EVT_CLOSE EVT_BUTTON EVT_SLIDER);
-use base 'Wx::Dialog';
-
-sub new {
-    my $class = shift;
-    my ($parent, %params) = @_;
-    my $self = $class->SUPER::new($parent, -1, $params{object}->name, wxDefaultPosition, [500,500], wxDEFAULT_DIALOG_STYLE | wxRESIZE_BORDER);
-    $self->{model_object} = $params{model_object};
-      my $model_object = $self->{model_object} = $params{model_object};
-      my $obj_idx = $self->{obj_idx} = $params{obj_idx};
-    my $plater = $self->{plater} = $parent;
-    my $object = $self->{plater}->{print}->get_object($self->{obj_idx});
-    
-    $self->{update_spline_control} = 0;
-
-    # Initialize 3D toolpaths preview
-    if ($Slic3r::GUI::have_OpenGL) {
-        $self->{preview3D} = Slic3r::GUI::Plater::3DPreview->new($self, $plater->{print});
-        $self->{preview3D}->canvas->set_auto_bed_shape;
-        $self->{preview3D}->canvas->SetSize([500,500]);
-        $self->{preview3D}->canvas->SetMinSize($self->{preview3D}->canvas->GetSize);
-        $self->{preview3D}->load_print;
-        $self->{preview3D}->canvas->zoom_to_volumes;
-    }
-
-    $self->{splineControl} = Slic3r::GUI::Plater::SplineControl->new($self, Wx::Size->new(150, 200), $model_object);
-
-    my $optgroup;
-    $optgroup = $self->{optgroup} = Slic3r::GUI::OptionsGroup->new(
-        parent      => $self,
-        title       => 'Adaptive quality %',
-        on_change   => sub {
-            my ($opt_id) = @_;
-            # There seems to be an issue with wxWidgets 3.0.2/3.0.3, where the slider
-            # genates tens of events for a single value change.
-            # Only trigger the recalculation if the value changes
-            # or a live preview was activated and the mesh cut is not valid yet.
-            if ($self->{adaptive_quality} != $optgroup->get_value($opt_id)) {
-                $self->{adaptive_quality} = $optgroup->get_value($opt_id);
-                $self->{model_object}->config->set('adaptive_slicing_quality', $optgroup->get_value($opt_id));
-                # trigger re-slicing
-                $self->_trigger_slicing;
-            }
-        },
-        label_width  => 0,
-    );
-
-    $optgroup->append_single_option_line(Slic3r::GUI::OptionsGroup::Option->new(
-        opt_id      => 'adaptive_slicing_quality',
-        type        => 'slider',
-        label       => '',
-        default     => $object->config->get('adaptive_slicing_quality'),
-        min         => 0,
-        max         => 100,
-        full_width  => 1,
-    ));
-    $optgroup->get_field('adaptive_slicing_quality')->set_scale(1);
-    $self->{adaptive_quality} = $object->config->get('adaptive_slicing_quality');
-    # init quality slider
-    if(!$object->config->get('adaptive_slicing')) {
-        # disable slider
-        $optgroup->get_field('adaptive_slicing_quality')->disable;
-    }
-
-
-    my $right_sizer = Wx::BoxSizer->new(wxVERTICAL);
-    $right_sizer->Add($self->{splineControl}, 1, wxEXPAND | wxALL, 0);
-    $right_sizer->Add($optgroup->sizer, 0, wxEXPAND | wxALL, 0);
-
-
-    $self->{sizer} = Wx::BoxSizer->new(wxHORIZONTAL);
-    $self->{sizer}->Add($self->{preview3D}, 3, wxEXPAND | wxTOP | wxBOTTOM, 0) if $self->{preview3D};
-    $self->{sizer}->Add($right_sizer, 1, wxEXPAND | wxTOP | wxBOTTOM, 10);
-
-    $self->SetSizerAndFit($self->{sizer});
-    $self->SetSize([800, 600]);
-    $self->SetMinSize($self->GetSize);
-
-    # init spline control values
-    # determine min and max layer height from perimeter extruder capabilities.
-    my %extruders;
-    for my $region_id (0 .. ($object->region_count - 1)) {
-        foreach (qw(perimeter_extruder infill_extruder solid_infill_extruder)) {
-            my $extruder_id = $self->{plater}->{print}->get_region($region_id)->config->get($_)-1;
-            $extruders{$extruder_id} = $extruder_id;
-        }
-    }
-    my $min_height = max(map {$self->{plater}->{print}->config->get_at('min_layer_height', $_)} (values %extruders));
-    my $max_height = min(map {$self->{plater}->{print}->config->get_at('max_layer_height', $_)} (values %extruders));
-    
-    $self->{splineControl}->set_size_parameters($min_height, $max_height, unscale($object->size->z));
-        
-    
-    $self->{splineControl}->on_layer_update(sub {
-        # trigger re-slicing
-        $self->_trigger_slicing;
-    });
-    
-    $self->{splineControl}->on_z_indicator(sub {
-        my ($z) = @_;
-        $self->{preview3D}->canvas->SetCuttingPlane(Z, $z, []);
-        $self->{preview3D}->canvas->Render;
-    });
-
-    return $self;
-}
-
-sub _trigger_slicing {
-    my ($self) = @_;
-    my $object = $self->{plater}->{print}->get_object($self->{obj_idx});
-    $self->{plater}->pause_background_process;
-    $self->{plater}->stop_background_process;
-    if (!$Slic3r::GUI::Settings->{_}{background_processing}) {
-        $self->{plater}->statusbar->SetCancelCallback(sub {
-            $self->{plater}->stop_background_process;
-            $self->{plater}->statusbar->SetStatusText("Slicing cancelled");
-            $self->{plater}->preview_notebook->SetSelection(0);
-        });
-        $self->{plater}->{print}->reload_object($self->{obj_idx});
-        $self->{plater}->on_model_change;
-        $self->{plater}->start_background_process;
-    }else{
-        $self->{plater}->{print}->reload_object($self->{obj_idx});
-        $self->{plater}->on_model_change;
-        $self->{plater}->schedule_background_process;
-    }
-}
-
-sub reload_preview {
-    my ($self) = @_;
-    $self->{splineControl}->update;
-    $self->{preview3D}->reload_print;
-    my $object = $self->{plater}->{print}->get_object($self->{obj_idx});
-    if($object->layer_count-1 > 0) {
-        # causes segfault...
-        my $top_layer = $object->get_layer($object->layer_count-1);
-        $self->{preview3D}->set_z($top_layer->print_z);
-    }
-}
-
-1;
diff --git a/lib/Slic3r/GUI/Plater/ObjectSettingsDialog.pm b/lib/Slic3r/GUI/Plater/ObjectSettingsDialog.pm
index c0979cd13..ba4d9999d 100644
--- a/lib/Slic3r/GUI/Plater/ObjectSettingsDialog.pm
+++ b/lib/Slic3r/GUI/Plater/ObjectSettingsDialog.pm
@@ -14,11 +14,16 @@ use base 'Wx::Dialog';
 sub new {
     my $class = shift;
     my ($parent, %params) = @_;
-    my $self = $class->SUPER::new($parent, -1, "Settings for " . $params{object}->name, wxDefaultPosition, [700,500], wxDEFAULT_DIALOG_STYLE | wxRESIZE_BORDER);
+    my $self = $class->SUPER::new($parent, -1, "Settings for " . $params{object}->name, wxDefaultPosition, [1000,700], wxDEFAULT_DIALOG_STYLE | wxRESIZE_BORDER);
     $self->{$_} = $params{$_} for keys %params;
     
     $self->{tabpanel} = Wx::Notebook->new($self, -1, wxDefaultPosition, wxDefaultSize, wxNB_TOP | wxTAB_TRAVERSAL);
     $self->{tabpanel}->AddPage($self->{parts} = Slic3r::GUI::Plater::ObjectPartsPanel->new($self->{tabpanel}, model_object => $params{model_object}), "Parts");
+    $self->{tabpanel}->AddPage($self->{adaptive_layers} = Slic3r::GUI::Plater::ObjectDialog::AdaptiveLayersTab->new( $self->{tabpanel}, 
+        plater         => $parent,
+        model_object   => $params{model_object},
+        obj_idx        => $params{obj_idx}
+        ), "Adaptive Layers");
     $self->{tabpanel}->AddPage($self->{layers} = Slic3r::GUI::Plater::ObjectDialog::LayersTab->new($self->{tabpanel}), "Layers");
     
     my $buttons = $self->CreateStdDialogButtonSizer(wxOK);
@@ -62,6 +67,157 @@ sub model_object {
     return $self->GetParent->GetParent->{model_object};
 }
 
+package Slic3r::GUI::Plater::ObjectDialog::AdaptiveLayersTab;
+use Slic3r::Geometry qw(X Y Z scale unscale);
+use List::Util qw(min max sum first);
+use Wx qw(wxTheApp :dialog :id :misc :sizer :systemsettings :statictext wxTAB_TRAVERSAL);
+use base 'Slic3r::GUI::Plater::ObjectDialog::BaseTab';
+
+sub new {
+    my $class = shift;
+    my ($parent, %params) = @_;
+    my $self = $class->SUPER::new($parent, -1, wxDefaultPosition, wxDefaultSize);
+    my $model_object = $self->{model_object} = $params{model_object};
+    my $obj_idx = $self->{obj_idx} = $params{obj_idx};
+    my $plater = $self->{plater} = $params{plater};
+    my $object = $self->{plater}->{print}->get_object($self->{obj_idx});
+
+    # Initialize 3D toolpaths preview
+    if ($Slic3r::GUI::have_OpenGL) {
+        $self->{preview3D} = Slic3r::GUI::Plater::3DPreview->new($self, $plater->{print});
+        $self->{preview3D}->canvas->set_auto_bed_shape;
+        $self->{preview3D}->canvas->SetSize([500,500]);
+        $self->{preview3D}->canvas->SetMinSize($self->{preview3D}->canvas->GetSize);
+        # object already processed?
+        wxTheApp->CallAfter(sub {
+            if (!$plater->{processed}) {
+                $self->_trigger_slicing;
+            }else{
+                $self->{preview3D}->load_print;
+                $self->{preview3D}->canvas->zoom_to_volumes;
+                $self->{preview_zoomed} = 1;
+            }
+        });
+    }
+
+    $self->{splineControl} = Slic3r::GUI::Plater::SplineControl->new($self, Wx::Size->new(150, 200), $model_object);
+
+    my $optgroup;
+    $optgroup = $self->{optgroup} = Slic3r::GUI::OptionsGroup->new(
+        parent      => $self,
+        title       => 'Adaptive quality %',
+        on_change   => sub {
+            my ($opt_id) = @_;
+            # There seems to be an issue with wxWidgets 3.0.2/3.0.3, where the slider
+            # genates tens of events for a single value change.
+            # Only trigger the recalculation if the value changes
+            # or a live preview was activated and the mesh cut is not valid yet.
+            if ($self->{adaptive_quality} != $optgroup->get_value($opt_id)) {
+                $self->{adaptive_quality} = $optgroup->get_value($opt_id);
+                $self->{model_object}->config->set('adaptive_slicing_quality', $optgroup->get_value($opt_id));
+                # trigger re-slicing
+                $self->_trigger_slicing;
+            }
+        },
+        label_width  => 0,
+    );
+
+    $optgroup->append_single_option_line(Slic3r::GUI::OptionsGroup::Option->new(
+        opt_id      => 'adaptive_slicing_quality',
+        type        => 'slider',
+        label       => '',
+        default     => $object->config->get('adaptive_slicing_quality'),
+        min         => 0,
+        max         => 100,
+        full_width  => 1,
+    ));
+    $optgroup->get_field('adaptive_slicing_quality')->set_scale(1);
+    $self->{adaptive_quality} = $object->config->get('adaptive_slicing_quality');
+    # init quality slider
+    if(!$object->config->get('adaptive_slicing')) {
+        # disable slider
+        $optgroup->get_field('adaptive_slicing_quality')->disable;
+    }
+
+    my $right_sizer = Wx::BoxSizer->new(wxVERTICAL);
+    $right_sizer->Add($self->{splineControl}, 1, wxEXPAND | wxALL, 0);
+    $right_sizer->Add($optgroup->sizer, 0, wxEXPAND | wxALL, 0);
+
+
+    $self->{sizer} = Wx::BoxSizer->new(wxHORIZONTAL);
+    $self->{sizer}->Add($self->{preview3D}, 3, wxEXPAND | wxTOP | wxBOTTOM, 0) if $self->{preview3D};
+    $self->{sizer}->Add($right_sizer, 1, wxEXPAND | wxTOP | wxBOTTOM, 10);
+
+    $self->SetSizerAndFit($self->{sizer});
+
+    # init spline control values
+    # determine min and max layer height from perimeter extruder capabilities.
+    my %extruders;
+    for my $region_id (0 .. ($object->region_count - 1)) {
+        foreach (qw(perimeter_extruder infill_extruder solid_infill_extruder)) {
+            my $extruder_id = $self->{plater}->{print}->get_region($region_id)->config->get($_)-1;
+            $extruders{$extruder_id} = $extruder_id;
+        }
+    }
+    my $min_height = max(map {$self->{plater}->{print}->config->get_at('min_layer_height', $_)} (values %extruders));
+    my $max_height = min(map {$self->{plater}->{print}->config->get_at('max_layer_height', $_)} (values %extruders));
+
+    $self->{splineControl}->set_size_parameters($min_height, $max_height, unscale($object->size->z));
+
+    $self->{splineControl}->on_layer_update(sub {
+        # trigger re-slicing
+        $self->_trigger_slicing;
+    });
+
+    $self->{splineControl}->on_z_indicator(sub {
+        my ($z) = @_;
+        $self->{preview3D}->canvas->SetCuttingPlane(Z, $z, []);
+        $self->{preview3D}->canvas->Render;
+    });
+
+    return $self;
+}
+
+# This is called by the plater after processing to update the preview and spline
+sub reload_preview {
+    my ($self) = @_;
+    $self->{splineControl}->update;
+    $self->{preview3D}->reload_print;
+    my $object = $self->{plater}->{print}->get_object($self->{obj_idx});
+    if($object->layer_count-1 > 0) {
+        my $top_layer = $object->get_layer($object->layer_count-1);
+        $self->{preview3D}->set_z($top_layer->print_z);
+        if(!$self->{preview_zoomed}) {
+            $self->{preview3D}->canvas->set_auto_bed_shape;
+            $self->{preview3D}->canvas->zoom_to_volumes;
+            $self->{preview_zoomed} = 1;
+        }
+    }
+}
+
+# Trigger background slicing at the plater
+sub _trigger_slicing {
+    my ($self) = @_;
+    my $object = $self->{plater}->{print}->get_object($self->{obj_idx});
+    $self->{plater}->pause_background_process;
+    $self->{plater}->stop_background_process;
+    if (!$Slic3r::GUI::Settings->{_}{background_processing}) {
+        $self->{plater}->statusbar->SetCancelCallback(sub {
+            $self->{plater}->stop_background_process;
+            $self->{plater}->statusbar->SetStatusText("Slicing cancelled");
+            $self->{plater}->preview_notebook->SetSelection(0);
+        });
+        $self->{plater}->{print}->reload_object($self->{obj_idx});
+        $self->{plater}->on_model_change;
+        $self->{plater}->start_background_process;
+    }else{
+        $self->{plater}->{print}->reload_object($self->{obj_idx});
+        $self->{plater}->on_model_change;
+        $self->{plater}->schedule_background_process;
+    }
+}
+
+
 package Slic3r::GUI::Plater::ObjectDialog::LayersTab;
 use Wx qw(:dialog :id :misc :sizer :systemsettings);
 use Wx::Grid;
diff --git a/lib/Slic3r/GUI/Plater/SplineControl.pm b/lib/Slic3r/GUI/Plater/SplineControl.pm
index 6de3ba0b3..f940ff11d 100644
--- a/lib/Slic3r/GUI/Plater/SplineControl.pm
+++ b/lib/Slic3r/GUI/Plater/SplineControl.pm
@@ -16,6 +16,7 @@ sub new {
     my $self = $class->SUPER::new($parent, -1, wxDefaultPosition, $size, wxTAB_TRAVERSAL);
     
     $self->{object} = $object;
+    $self->{is_valid} = 0;
     
     # This has only effect on MacOS. On Windows and Linux/GTK, the background is painted by $self->repaint().
     $self->SetBackgroundColour(Wx::wxWHITE);
@@ -74,31 +75,33 @@ sub repaint {
     $dc->DrawLabel(sprintf('%.4g', $self->{min_layer_height}), Wx::Rect->new(0, $size[1]/2, $size[0], $size[1]/2), wxALIGN_LEFT | wxALIGN_BOTTOM);
     $dc->DrawLabel(sprintf('%.4g', $self->{max_layer_height}), Wx::Rect->new(0, $size[1]/2, $size[0], $size[1]/2), wxALIGN_RIGHT | wxALIGN_BOTTOM);
 
+    if($self->{is_valid}) {
 
-    # draw original spline as reference
-    if($self->{original_height_spline}) {
-        #draw spline
-        $self->_draw_layer_height_spline($dc, $self->{original_height_spline}, $self->{original_pen});
-    }
-    
-    # draw interactive (currently modified by the user) layers as lines and spline
-    if($self->{interactive_height_spline}) {
-        # draw layer lines
-        my @interpolated_layers = @{$self->{interactive_height_spline}->getInterpolatedLayers};
-        $self->_draw_layers_as_lines($dc, $self->{interactive_pen}, \@interpolated_layers);
-        
-        #draw spline
-        $self->_draw_layer_height_spline($dc, $self->{interactive_height_spline}, $self->{interactive_pen});
+        # draw original spline as reference
+        if($self->{original_height_spline}) {
+            #draw spline
+            $self->_draw_layer_height_spline($dc, $self->{original_height_spline}, $self->{original_pen});
+        }
+
+        # draw interactive (currently modified by the user) layers as lines and spline
+        if($self->{interactive_height_spline}) {
+            # draw layer lines
+            my @interpolated_layers = @{$self->{interactive_height_spline}->getInterpolatedLayers};
+            $self->_draw_layers_as_lines($dc, $self->{interactive_pen}, \@interpolated_layers);
+
+            #draw spline
+            $self->_draw_layer_height_spline($dc, $self->{interactive_height_spline}, $self->{interactive_pen});
+        }
+
+        # draw resulting layers as lines
+        unless($self->{interactive_heights}) {
+            $self->_draw_layers_as_lines($dc, $self->{resulting_pen}, $self->{interpolated_layers});
+        }
+
+        # Always draw current BSpline, gives a reference during a modification
+        $self->_draw_layer_height_spline($dc, $self->{object}->layer_height_spline, $self->{line_pen});
     }
 
-    # draw resulting layers as lines
-    unless($self->{interactive_heights}) {
-        $self->_draw_layers_as_lines($dc, $self->{resulting_pen}, $self->{interpolated_layers});
-    }
-
-    # Always draw current BSpline, gives a reference during a modification
-    $self->_draw_layer_height_spline($dc, $self->{object}->layer_height_spline, $self->{line_pen});
-    
     $event->Skip;
 }
 
@@ -120,7 +123,7 @@ sub set_size_parameters {
 sub update {
     my $self = shift;
 
-    if($self->{object}->layer_height_spline->layersUpdated || !$self->{heights}) {
+    if(($self->{object}->layer_height_spline->layersUpdated || !$self->{heights}) && $self->{object}->layer_height_spline->hasData) {
         $self->{original_height_spline} = $self->{object}->layer_height_spline->clone; # make a copy to display the unmodified original spline
         $self->{original_layers} = $self->{object}->layer_height_spline->getOriginalLayers;
         $self->{interpolated_layers} = $self->{object}->layer_height_spline->getInterpolatedLayers; # Initialize to current values
@@ -131,6 +134,7 @@ sub update {
         foreach my $z (@{$self->{original_layers}}) {
             push (@{$self->{heights}}, $self->{object}->layer_height_spline->getLayerHeightAt($z));
         }
+        $self->{is_valid} = 1;
     }
     $self->Refresh;
 }