Propagate bone's ResetPoseToRest

This helps for intialization and if the users wants to reset
the pose mode.

See Issue 13676

Libs/VTK/Widgets/vtkArmatureWidget.cxx

@@ -178,6 +178,7 @@ vtkArmatureWidget::vtkArmatureWidget()
   this->WidgetState = vtkArmatureWidget::Rest;
   this->ShowAxes = vtkBoneWidget::Hidden;
   this->ShowParenthood = true;
+  this->ShouldResetPoseToRest = true;
 }
 
 //----------------------------------------------------------------------------
@@ -384,8 +385,14 @@ void vtkArmatureWidget::SetWidgetState(int state)
       for (NodeIteratorType it = this->Bones->begin();
         it != this->Bones->end(); ++it)
         {
+        if (this->ShouldResetPoseToRest)
+          {
+          (*it)->Bone->ResetPoseToRest();
+          }
         (*it)->Bone->SetWidgetStateToPose();
         }
+
+      this->ShouldResetPoseToRest = false;
       break;
       }
     default:
@@ -632,6 +639,11 @@ ::UpdateBoneWithArmatureOptions(vtkBoneWidget* bone, vtkBoneWidget* parent)
   bone->SetShowAxes(this->ShowAxes);
   bone->SetShowParenthood(this->ShowParenthood);
 
+  if (this->ShouldResetPoseToRest)
+    {
+    bone->ResetPoseToRest();
+    }
+
   if (this->WidgetState == vtkArmatureWidget::Rest)
     {
     this->SetBoneWorldToParentRestTransform(bone, parent);
@@ -675,6 +687,18 @@ ::ReparentBone(vtkBoneWidget* bone, vtkBoneWidget* newParent)
     }
 }
 
+//----------------------------------------------------------------------------
+void vtkArmatureWidget::ResetPoseToRest()
+{
+  int oldState = this->WidgetState;
+  this->ShouldResetPoseToRest = true;
+  this->SetWidgetState(vtkArmatureWidget::Pose);
+  if(oldState == vtkArmatureWidget::Rest)
+    {
+    this->SetWidgetState(vtkArmatureWidget::Rest);
+    }
+}
+
 //----------------------------------------------------------------------------
 void vtkArmatureWidget
 ::SetBoneWorldToParentTransform(vtkBoneWidget* bone, vtkBoneWidget* parent)

Libs/VTK/Widgets/vtkArmatureWidget.h

@@ -238,6 +238,11 @@ class VTK_BENDER_WIDGETS_EXPORT vtkArmatureWidget : public vtkAbstractWidget
   // Sa AddBone(), RemoveBone, ArmatureEventType
   void ReparentBone(vtkBoneWidget* bone, vtkBoneWidget* newParent);
 
+  // Description:
+  // Reset the pose positions to the initial rest position with no rotations
+  // or translations.
+  void ResetPoseToRest();
+
 protected:
   vtkArmatureWidget();
   ~vtkArmatureWidget();
@@ -261,6 +266,7 @@ class VTK_BENDER_WIDGETS_EXPORT vtkArmatureWidget : public vtkAbstractWidget
   int WidgetState;
   int ShowAxes;
   int ShowParenthood;
+  bool ShouldResetPoseToRest;
 
   // Add/Remove all the necessaries observers to a bone
   void AddBoneObservers(vtkBoneWidget* bone);