diff --git a/components/sceneutil/mwshadowtechnique.cpp b/components/sceneutil/mwshadowtechnique.cpp
index 95ff8f2b01..db7aef7cb1 100644
--- a/components/sceneutil/mwshadowtechnique.cpp
+++ b/components/sceneutil/mwshadowtechnique.cpp
@@ -353,18 +353,20 @@ void VDSMCameraCullCallback::operator()(osg::Node* node, osg::NodeVisitor* nv)
 
 } // namespace
 
-MWShadowTechnique::ComputeLightSpaceBounds::ComputeLightSpaceBounds(osg::Viewport* viewport, const osg::Matrixd& projectionMatrix, osg::Matrixd& viewMatrix) :
+MWShadowTechnique::ComputeLightSpaceBounds::ComputeLightSpaceBounds() :
     osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ACTIVE_CHILDREN)
 {
     setCullingMode(osg::CullSettings::VIEW_FRUSTUM_CULLING);
 
-    pushViewport(viewport);
-    pushProjectionMatrix(new osg::RefMatrix(projectionMatrix));
-    pushModelViewMatrix(new osg::RefMatrix(viewMatrix), osg::Transform::ABSOLUTE_RF);
-
     setName("SceneUtil::MWShadowTechnique::ComputeLightSpaceBounds,AcceptedByComponentsTerrainQuadTreeWorld");
 }
 
+void MWShadowTechnique::ComputeLightSpaceBounds::reset()
+{
+    osg::CullStack::reset();
+    _bb = osg::BoundingBox();
+}
+
 void MWShadowTechnique::ComputeLightSpaceBounds::apply(osg::Node& node)
 {
     if (isCulled(node)) return;
@@ -421,9 +423,9 @@ void MWShadowTechnique::ComputeLightSpaceBounds::apply(osg::Transform& transform
     // absolute transforms won't affect a shadow map so their subgraphs should be ignored.
     if (transform.getReferenceFrame() == osg::Transform::RELATIVE_RF)
     {
-        osg::ref_ptr<osg::RefMatrix> matrix = new osg::RefMatrix(*getModelViewMatrix());
+        osg::RefMatrix* matrix = createOrReuseMatrix(*getModelViewMatrix());
         transform.computeLocalToWorldMatrix(*matrix, this);
-        pushModelViewMatrix(matrix.get(), transform.getReferenceFrame());
+        pushModelViewMatrix(matrix, transform.getReferenceFrame());
 
         traverse(transform);
 
@@ -1125,7 +1127,12 @@ void MWShadowTechnique::cull(osgUtil::CullVisitor& cv)
             // osg::ElapsedTime timer;
 
             osg::ref_ptr<osg::Viewport> viewport = new osg::Viewport(0,0,2048,2048);
-            ComputeLightSpaceBounds clsb(viewport.get(), projectionMatrix, viewMatrix);
+            if (!_clsb) _clsb = new ComputeLightSpaceBounds;
+            ComputeLightSpaceBounds& clsb = *_clsb;
+            clsb.reset();
+            clsb.pushViewport(viewport);
+            clsb.pushProjectionMatrix(new osg::RefMatrix(projectionMatrix));
+            clsb.pushModelViewMatrix(new osg::RefMatrix(viewMatrix), osg::Transform::ABSOLUTE_RF);
             clsb.setTraversalMask(_shadowedScene->getCastsShadowTraversalMask());
 
             osg::Matrixd invertModelView;
@@ -1139,6 +1146,12 @@ void MWShadowTechnique::cull(osgUtil::CullVisitor& cv)
 
             _shadowedScene->accept(clsb);
 
+            clsb.popCullingSet();
+
+            clsb.popModelViewMatrix();
+            clsb.popProjectionMatrix();
+            clsb.popViewport();
+
             // OSG_NOTICE<<"Extents of LightSpace "<<clsb._bb.xMin()<<", "<<clsb._bb.xMax()<<", "<<clsb._bb.yMin()<<", "<<clsb._bb.yMax()<<", "<<clsb._bb.zMin()<<", "<<clsb._bb.zMax()<<std::endl;
             // OSG_NOTICE<<"  time "<<timer.elapsedTime_m()<<"ms, mask = "<<std::hex<<_shadowedScene->getCastsShadowTraversalMask()<<std::endl;
 
diff --git a/components/sceneutil/mwshadowtechnique.hpp b/components/sceneutil/mwshadowtechnique.hpp
index de57bf1fdc..229d444c2b 100644
--- a/components/sceneutil/mwshadowtechnique.hpp
+++ b/components/sceneutil/mwshadowtechnique.hpp
@@ -90,7 +90,7 @@ namespace SceneUtil {
         class ComputeLightSpaceBounds : public osg::NodeVisitor, public osg::CullStack
         {
         public:
-            ComputeLightSpaceBounds(osg::Viewport* viewport, const osg::Matrixd& projectionMatrix, osg::Matrixd& viewMatrix);
+            ComputeLightSpaceBounds();
 
             void apply(osg::Node& node) override;
 
@@ -112,6 +112,8 @@ namespace SceneUtil {
 
             void update(const osg::Vec3& v);
 
+            void reset() override;
+
             osg::BoundingBox _bb;
         };
 
@@ -238,6 +240,8 @@ namespace SceneUtil {
     protected:
         virtual ~MWShadowTechnique();
 
+        osg::ref_ptr<ComputeLightSpaceBounds>   _clsb;
+
         typedef std::map< osgUtil::CullVisitor*, osg::ref_ptr<ViewDependentData> >  ViewDependentDataMap;
         mutable std::mutex                      _viewDependentDataMapMutex;
         ViewDependentDataMap                    _viewDependentDataMap;