From ce2a65db85f811aef08c718d7a7db11b5a66e55a Mon Sep 17 00:00:00 2001
From: Fangjun Kuang <csukuangfj@gmail.com>
Date: Sun, 11 Feb 2018 20:08:53 +0800
Subject: [PATCH] fix issue #9486.

---
 modules/viz/src/widget.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/modules/viz/src/widget.cpp b/modules/viz/src/widget.cpp
index b324a4e26c..6e56e04155 100644
--- a/modules/viz/src/widget.cpp
+++ b/modules/viz/src/widget.cpp
@@ -284,6 +284,10 @@ cv::Affine3d cv::viz::Widget3D::getPose() const
 {
     vtkProp3D *actor = vtkProp3D::SafeDownCast(WidgetAccessor::getProp(*this));
     CV_Assert("Widget is not 3D." && actor);
+    if (!actor->GetUserMatrix())
+    {
+        return Affine3d(); // empty user matrix, return an identity transform.
+    }
     return Affine3d(*actor->GetUserMatrix()->Element);
 }