arrow widget thickness parameter

modules/viz/include/opencv2/viz/widgets.hpp

@@ -81,7 +81,7 @@ namespace cv
         class CV_EXPORTS ArrowWidget : public Widget3D
         {
         public:
-            ArrowWidget(const Point3f& pt1, const Point3f& pt2, const Color &color = Color::white());
+            ArrowWidget(const Point3f& pt1, const Point3f& pt2, double thickness = 0.03, const Color &color = Color::white());
         };
 
         class CV_EXPORTS CircleWidget : public Widget3D

modules/viz/src/shape_widgets.cpp

@@ -128,9 +128,13 @@ template<> cv::viz::SphereWidget cv::viz::Widget::cast<cv::viz::SphereWidget>()
 ///////////////////////////////////////////////////////////////////////////////////////////////
 /// arrow widget implementation
 
-cv::viz::ArrowWidget::ArrowWidget(const Point3f& pt1, const Point3f& pt2, const Color &color)
+cv::viz::ArrowWidget::ArrowWidget(const Point3f& pt1, const Point3f& pt2, double thickness, const Color &color)
 {
     vtkSmartPointer<vtkArrowSource> arrowSource = vtkSmartPointer<vtkArrowSource>::New ();
+    arrowSource->SetShaftRadius(thickness);
+    // The thickness and radius of the tip are adjusted based on the thickness of the arrow
+    arrowSource->SetTipRadius(thickness * 3.0);
+    arrowSource->SetTipLength(thickness * 10.0);
     
     float startPoint[3], endPoint[3];
     startPoint[0] = pt1.x;

modules/viz/test/test_viz3d.cpp

@@ -90,7 +90,7 @@ TEST(Viz_viz3d, accuracy)
     viz::LineWidget lw(Point3f(0, 0, 0), Point3f(4.f, 4.f,4.f), viz::Color::green());
     viz::PlaneWidget pw(Vec4f(0.0,1.0,2.0,3.0), 5.0);
     viz::SphereWidget sw(Point3f(0, 0, 0), 0.5);
-    viz::ArrowWidget aw(Point3f(0, 0, 0), Point3f(1, 1, 1), viz::Color::red());
+    viz::ArrowWidget aw(Point3f(0, 0, 0), Point3f(1, 1, 1), 0.01, viz::Color::red());
     viz::CircleWidget cw(Point3f(0, 0, 0), 0.5, 0.01, viz::Color::green());
     viz::CylinderWidget cyw(Point3f(0, 0, 0), Point3f(-1, -1, -1), 0.5, 30, viz::Color::green());
     viz::CubeWidget cuw(Point3f(-2, -2, -2), Point3f(-1, -1, -1));