ENH: Render on timer event from window interactor

1) Create a timer on the renderWindowInteractor
2) Render() in 'InteractorStyle::OnTimer()'

Base/SimulationManager/imstkInteractorStyle.cpp

@@ -31,9 +31,23 @@
 #include "vtkAssemblyPath.h"
 #include "vtkAbstractPropPicker.h"
 
-vtkStandardNewMacro(imstk::InteractorStyle);
-
 namespace imstk {
+
+vtkStandardNewMacro(InteractorStyle);
+
+void
+InteractorStyle::OnTimer()
+{
+    if (m_simManager->getStatus() == SimulationStatus::INACTIVE)
+    {
+        return;
+    }
+
+    // Render
+    this->CurrentRenderer->ResetCameraClippingRange();
+    this->Interactor->Render();
+}
+
 void
 InteractorStyle::OnChar()
 {

Base/SimulationManager/imstkInteractorStyle.h

@@ -37,6 +37,7 @@ public:
     static InteractorStyle *New();
     vtkTypeMacro(InteractorStyle, vtkBaseInteractorStyle);
 
+    virtual void OnTimer() override;
     virtual void OnChar() override;
     virtual void OnMouseMove() override;
     virtual void OnLeftButtonDown() override;

Base/SimulationManager/imstkViewer.cpp

@@ -108,7 +108,10 @@ void
 Viewer::startRenderingLoop()
 {
     m_running = true;
+    m_vtkRenderWindow->GetInteractor()->Initialize();
+    m_vtkRenderWindow->GetInteractor()->CreateRepeatingTimer(1000.0/60);
     m_vtkRenderWindow->GetInteractor()->Start();
+    m_vtkRenderWindow->GetInteractor()->DestroyTimer();
     m_running = false;
 }