From 412a8626776fd303c49e4b7943afcf1030053509 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Sat, 19 Mar 2016 22:30:01 +0100
Subject: [PATCH] Fixed dragging in 3D plater having some glitches with
 multipart objects

---
 lib/Slic3r/GUI/Plater/3D.pm | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/Slic3r/GUI/Plater/3D.pm b/lib/Slic3r/GUI/Plater/3D.pm
index 5928625ef..07818a2b5 100644
--- a/lib/Slic3r/GUI/Plater/3D.pm
+++ b/lib/Slic3r/GUI/Plater/3D.pm
@@ -39,10 +39,14 @@ sub new {
     $self->on_move(sub {
         my @volume_idxs = @_;
         
+        my %done = ();  # prevent moving instances twice
         foreach my $volume_idx (@volume_idxs) {
             my $volume = $self->volumes->[$volume_idx];
             my $obj_idx = $self->object_idx($volume_idx);
             my $instance_idx = $self->instance_idx($volume_idx);
+            next if $done{"${obj_idx}_${instance_idx}"};
+            $done{"${obj_idx}_${instance_idx}"} = 1;
+            
             my $model_object = $self->{model}->get_object($obj_idx);
             $model_object
                 ->instances->[$instance_idx]