Bugfix: when using low layer heights and support material, the contac…

…t regions were generated with a negative height. #1013
slic3r · Feb 23, 2013 · 5049627 · 5049627
1 parent 3eedd4b
commit 5049627
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Showing 3 changed files with 42 additions and 18 deletions.
diff --git a/lib/Slic3r/Layer.pm b/lib/Slic3r/Layer.pm
@@ -64,7 +64,16 @@ sub support_material_contact_height {
 
     # TODO: check what upper region applies instead of considering the first one
     my $upper_layer = $self->object->layers->[ $self->id + 1 ] // $self;
-    return 2*$self->height - $upper_layer->regions->[0]->infill_flow->bridge_width;
+    my $h = ($self->height + $upper_layer->height) - $upper_layer->regions->[0]->infill_flow->bridge_width;
+
+    # If layer height is less than half the bridge width then we'll get a negative height for contact area.
+    # The optimal solution would be to skip some layers during support material generation, but for now
+    # we'll apply a (dirty) workaround that should still work.
+    if ($h <= 0) {
+        $h = $self->height;
+    }
+
+    return $h;
 }
 
 # Z used for printing support material contact in scaled coordinates

diff --git a/lib/Slic3r/Test.pm b/lib/Slic3r/Test.pm
@@ -15,30 +15,34 @@ my %cuboids = (
     '2x20x10'   => [2, 20,10],
 );
 
-sub init_print {
-    my ($model_name, %params) = @_;
+sub model {
+    my ($model_name) = @_;
 
-    my $model = Slic3r::Model->new;
-    {
-        my ($vertices, $facets);
-        if ($cuboids{$model_name}) {
-            my ($x, $y, $z) = @{ $cuboids{$model_name} };
-            $vertices = [
-                [$x,$y,0], [$x,0,0], [0,0,0], [0,$y,0], [$x,$y,$z], [0,$y,$z], [0,0,$z], [$x,0,$z],
-            ];
-            $facets = [
-                [0,1,2], [0,2,3], [4,5,6], [4,6,7], [0,4,7], [0,7,1], [1,7,6], [1,6,2], [2,6,5], [2,5,3], [4,0,3], [4,3,5],
-            ],
-        }
-        $model->add_object(vertices => $vertices)->add_volume(facets => $facets);
+    my ($vertices, $facets);
+    if ($cuboids{$model_name}) {
+        my ($x, $y, $z) = @{ $cuboids{$model_name} };
+        $vertices = [
+            [$x,$y,0], [$x,0,0], [0,0,0], [0,$y,0], [$x,$y,$z], [0,$y,$z], [0,0,$z], [$x,0,$z],
+        ];
+        $facets = [
+            [0,1,2], [0,2,3], [4,5,6], [4,6,7], [0,4,7], [0,7,1], [1,7,6], [1,6,2], [2,6,5], [2,5,3], [4,0,3], [4,3,5],
+        ],
     }
 
+    my $model = Slic3r::Model->new;
+    $model->add_object(vertices => $vertices)->add_volume(facets => $facets);
+    return $model;
+}
+
+sub init_print {
+    my ($model_name, %params) = @_;
+
     my $config = Slic3r::Config->new_from_defaults;
     $config->apply($params{config}) if $params{config};
     $config->set('gcode_comments', 1) if $ENV{SLIC3R_TESTS_GCODE};
 
     my $print = Slic3r::Print->new(config => $config);
-    $print->add_model($model);
+    $print->add_model(model($model_name));
     $print->validate;
 
     return $print;

diff --git a/t/layers.t b/t/layers.t
@@ -1,4 +1,4 @@
-use Test::More tests => 4;
+use Test::More tests => 5;
 use strict;
 use warnings;
 
@@ -55,4 +55,15 @@ ok $test->(), "positive Z offset";
 $config->set('z_offset', -0.8);
 ok $test->(), "negative Z offset";
 
+{
+    my $config = Slic3r::Config->new_from_defaults;
+    $config->set('nozzle_diameter', [0.35]);
+    $config->set('layer_height', 0.1333);
+
+    my $print = Slic3r::Test::init_print('2x20x10', config => $config);
+    $print->init_extruders;
+    $_->region(0) for @{$print->objects->[0]->layers};  # init layer regions
+    ok $print->objects->[0]->layers->[1]->support_material_contact_height > 0, 'support_material_contact_height is positive';
+}
+
 __END__