BUG: Fix distance encoded projection in Slice view

- Implicit plane function for calculating distance uses SliceXYToRAS, however the distance is scaled in the Z direction
- Fixed by normalizing the plane normal used for distance encoded projection

git-svn-id: http://svn.slicer.org/Slicer4/trunk@27946 3bd1e089-480b-0410-8dfb-8563597acbee

Author: lassoan

Libs/MRML/DisplayableManager/vtkMRMLModelSliceDisplayableManager.cxx

@@ -262,6 +262,7 @@ ::SetSlicePlaneFromMatrix(vtkMatrix4x4* sliceMatrix, vtkPlane* plane)
     origin[i] = sliceMatrix->GetElement(i,3);
     }
 
+  vtkMath::Normalize(normal);
   plane->SetNormal(normal);
   plane->SetOrigin(origin);
 }

Modules/Loadable/Segmentations/MRMLDM/vtkMRMLSegmentationsDisplayableManager2D.cxx

@@ -421,6 +421,7 @@ void vtkMRMLSegmentationsDisplayableManager2D::vtkInternal::SetSlicePlaneFromMat
     origin[i] = sliceMatrix->GetElement(i,3);
     }
 
+  vtkMath::Normalize(normal);
   plane->SetNormal(normal);
   plane->SetOrigin(origin);
 }