From a3869736ba6073cd3346ac32d8f42984fe934ce6 Mon Sep 17 00:00:00 2001
From: Lukas Matena <lukasmatena@seznam.cz>
Date: Thu, 27 Feb 2020 10:54:24 +0100
Subject: [PATCH] SLA gizmos can now be opened when any instance is selected
 This was broken - only first instance worked

---
 src/slic3r/GUI/Gizmos/GLGizmoBase.cpp | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/slic3r/GUI/Gizmos/GLGizmoBase.cpp b/src/slic3r/GUI/Gizmos/GLGizmoBase.cpp
index 52518878f..fc644f5ca 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoBase.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoBase.cpp
@@ -322,14 +322,20 @@ bool CommonGizmosData::update_from_backend(GLCanvas3D& canvas, ModelObject* mode
         m_old_mesh = nullptr;
         m_mesh = nullptr;
         m_backend_mesh_transformed.clear();
-        if (m_model_object) {
-            m_active_instance = canvas.get_selection().get_instance_idx();
-            m_active_instance_bb_radius = m_model_object->instance_bounding_box(m_active_instance).radius();
-        }
+
         object_changed = true;
         recent_update = true;
     }
 
+    if (m_model_object) {
+        int active_inst = canvas.get_selection().get_instance_idx();
+        if (m_active_instance != active_inst) {
+            m_active_instance = active_inst;
+            m_active_instance_bb_radius = m_model_object->instance_bounding_box(m_active_instance).radius();
+            recent_update = true;
+        }
+    }
+
 
     if (! m_model_object || ! canvas.get_selection().is_from_single_instance())
         return false;