Refs #6818. Add ability to change LOD on view.

Code/Mantid/Vates/VatesSimpleGui/ViewWidgets/inc/MantidVatesSimpleGuiViewWidgets/ViewBase.h

@@ -121,6 +121,8 @@ public slots:
   void onColorMapChange(const pqColorMapModel *model);
   /// Set the data color scale range to the requested bounds.
   void onColorScaleChange(double min, double max);
+  /// Set the view to use a LOD threshold.
+  void onLodThresholdChange(bool state, double defVal);
   /// Set logarithmic color scaling on the data.
   void onLogScale(int state);
   /// Set the view to use a parallel projection.

Code/Mantid/Vates/VatesSimpleGui/ViewWidgets/src/ViewBase.cpp

@@ -415,6 +415,27 @@ void ViewBase::onParallelProjection(bool state)
   cview->render();
 }
 
+/**
+ * This function is used to set the LOD threshold for the view.
+ * @param state : whether or not to use the LOD threshold
+ * @param defVal : default value of LOD threshold
+ */
+void ViewBase::onLodThresholdChange(bool state, double defVal)
+{
+  pqRenderView *cview = this->getPvActiveView();
+  vtkSMProxy *proxy = cview->getProxy();
+  if (state)
+  {
+    vtkSMPropertyHelper(proxy, "LODThreshold").Set(defVal);
+  }
+  else
+  {
+    vtkSMPropertyHelper(proxy, "LODThreshold").Set(VTK_DOUBLE_MAX);
+  }
+  proxy->UpdateVTKObjects();
+  cview->render();
+}
+
 /**
  * This function retrieves the active pqRenderView object according to
  * ParaView's ActiveObjects mechanism.