diff --git a/include/osgGA/MatrixManipulator b/include/osgGA/MatrixManipulator
index 81ff9ee51..cf182811a 100644
--- a/include/osgGA/MatrixManipulator
+++ b/include/osgGA/MatrixManipulator
@@ -100,6 +100,12 @@ public:
         /** Get the FusionDistanceValue. Used by SceneView for setting up setereo convergence.*/
         virtual float getFusionDistanceValue() const { return 1.0f; }
 
+        /** Set the mask to use when set up intersection traversal such as used in manipulators that follow terrain or have collision detection.
+          * The intersection traversal mask is useful for controlling what parts of the scene graph should be used for intersection purposes.*/
+        void setIntersectTraversalMask(unsigned int mask) { _intersectTraversalMask = mask; }
+
+        /** Get the mask to use when set up intersection traversal such as used in manipulators that follow terrain or have collision detection.*/
+        unsigned int getIntersectTraversalMask() const { return _intersectTraversalMask; }
 
         /**
         Attach a node to the manipulator, automatically detaching any previously attached node.
@@ -185,6 +191,8 @@ protected:
 
         double                  _minimumDistance;
         
+        unsigned int            _intersectTraversalMask;
+
         bool                    _autoComputeHomePosition;
         
         osg::Vec3d              _homeEye;
@@ -192,6 +200,7 @@ protected:
         osg::Vec3d              _homeUp;
 
         osg::ref_ptr<CoordinateFrameCallback> _coordinateFrameCallback;
+
 };
 
 }
diff --git a/src/osgGA/DriveManipulator.cpp b/src/osgGA/DriveManipulator.cpp
index 2b81b30a3..f3450fcf7 100644
--- a/src/osgGA/DriveManipulator.cpp
+++ b/src/osgGA/DriveManipulator.cpp
@@ -105,6 +105,7 @@ void DriveManipulator::computeHomePosition()
 
         // check to see if any obstruction in front.
         osgUtil::IntersectVisitor iv;
+        iv.setTraversalMask(_intersectTraversalMask);
 
         bool positionSet = false;
 
@@ -223,6 +224,7 @@ void DriveManipulator::init(const GUIEventAdapter& ea,GUIActionAdapter& us)
 
     // check to see if any obstruction in front.
     osgUtil::IntersectVisitor iv;
+    iv.setTraversalMask(_intersectTraversalMask);
 
     bool positionSet = false;
 
@@ -574,6 +576,8 @@ bool DriveManipulator::calcMovement()
 
         // check to see if any obstruction in front.
         osgUtil::IntersectVisitor iv;
+        iv.setTraversalMask(_intersectTraversalMask);
+    
         osg::ref_ptr<osg::LineSegment> segForward = new osg::LineSegment;
         segForward->set(_eye,_eye+lv*(signedBuffer+distanceToMove));
         iv.addLineSegment(segForward.get());
diff --git a/src/osgGA/MatrixManipulator.cpp b/src/osgGA/MatrixManipulator.cpp
index 2c226cc85..90416db5a 100644
--- a/src/osgGA/MatrixManipulator.cpp
+++ b/src/osgGA/MatrixManipulator.cpp
@@ -9,6 +9,8 @@ MatrixManipulator::MatrixManipulator()
 {
     _minimumDistance = 0.001;
     
+    _intersectTraversalMask = 0xffffffff;
+
     _autoComputeHomePosition = true;
         
     _homeEye.set(0.0,-1.0,0.0);
diff --git a/src/osgGA/TerrainManipulator.cpp b/src/osgGA/TerrainManipulator.cpp
index b5c92176b..b99e2a27b 100644
--- a/src/osgGA/TerrainManipulator.cpp
+++ b/src/osgGA/TerrainManipulator.cpp
@@ -214,6 +214,7 @@ void TerrainManipulator::setByMatrix(const osg::Matrixd& matrix)
 
     // need to reintersect with the terrain
     osgUtil::IntersectVisitor iv;
+    iv.setTraversalMask(_intersectTraversalMask);
 
     const osg::BoundingSphere& bs = _node->getBound();
     float distance = (eye-bs.center()).length() + _node->getBound().radius();
@@ -327,6 +328,7 @@ void TerrainManipulator::computePosition(const osg::Vec3d& eye,const osg::Vec3d&
         {
             // compute the itersection with the scene.
             osgUtil::IntersectVisitor iv;
+            iv.setTraversalMask(_intersectTraversalMask);
 
             osg::ref_ptr<osg::LineSegment> segLookVector = new osg::LineSegment;
             segLookVector->set(eye,endPoint );
@@ -475,6 +477,7 @@ bool TerrainManipulator::calcMovement()
 
             // need to reintersect with the terrain
             osgUtil::IntersectVisitor iv;
+            iv.setTraversalMask(_intersectTraversalMask);
 
             double distance = _node->getBound().radius()*0.1f;
             osg::Vec3d start_segment = _center + getUpVector(coordinateFrame) * distance;
diff --git a/src/osgGA/TrackballManipulator.cpp b/src/osgGA/TrackballManipulator.cpp
index 5c94ccf5c..c1e03b96f 100644
--- a/src/osgGA/TrackballManipulator.cpp
+++ b/src/osgGA/TrackballManipulator.cpp
@@ -46,7 +46,7 @@ osg::Node* TrackballManipulator::getNode()
 }
 
 
-void TrackballManipulator::home(double currentTime)
+void TrackballManipulator::home(double /*currentTime*/)
 {
     if (getAutoComputeHomePosition()) computeHomePosition();
     computePosition(_homeEye, _homeCenter, _homeUp);
diff --git a/src/osgGA/UFOManipulator.cpp b/src/osgGA/UFOManipulator.cpp
index 996ceb287..e40a1fc1b 100644
--- a/src/osgGA/UFOManipulator.cpp
+++ b/src/osgGA/UFOManipulator.cpp
@@ -100,6 +100,8 @@ void UFOManipulator::computeHomePosition()
        * from a line segment extending from above to below the database at its 
        * horizontal center, that intersects the database closest to zero. */
     osgUtil::IntersectVisitor iv;
+    iv.setTraversalMask(_intersectTraversalMask);
+
     osg::ref_ptr<osg::LineSegment> seg = new osg::LineSegment;
     osg::Vec3 A = bs.center() + (osg::Vec3(0,0,1)*(bs.radius()*2));
     osg::Vec3 B = bs.center() + (osg::Vec3(0,0,-1)*(bs.radius()*2));
@@ -475,6 +477,7 @@ void UFOManipulator::_adjustPosition()
         return;
 
     osgUtil::IntersectVisitor iv;
+    iv.setTraversalMask(_intersectTraversalMask);
 
     // Forward line segment at 3 times our intersect distance
     osg::ref_ptr<osg::LineSegment> segForward = new osg::LineSegment;