diff --git a/include/osgAnimation/StackedMatrixElement b/include/osgAnimation/StackedMatrixElement
index 1a33c7ccb..7e6835d6d 100644
--- a/include/osgAnimation/StackedMatrixElement
+++ b/include/osgAnimation/StackedMatrixElement
@@ -39,7 +39,7 @@ namespace osgAnimation
         const osg::Matrix& getMatrix() const { return _matrix;}
         void setMatrix(const osg::Matrix& matrix) { _matrix = matrix;}
         bool isIdentity() const { return _matrix.isIdentity(); }
-        void update();
+        void update(float t = 0.0);
         virtual Target* getOrCreateTarget();
         virtual Target* getTarget() {return _target.get();}
         virtual const Target* getTarget() const {return _target.get();}
diff --git a/include/osgAnimation/StackedQuaternionElement b/include/osgAnimation/StackedQuaternionElement
index 1384950c1..aea2a1df7 100644
--- a/include/osgAnimation/StackedQuaternionElement
+++ b/include/osgAnimation/StackedQuaternionElement
@@ -36,7 +36,7 @@ namespace osgAnimation
         void applyToMatrix(osg::Matrix& matrix) const;
         osg::Matrix getAsMatrix() const;
         bool isIdentity() const;
-        void update();
+        void update(float t = 0.0);
 
         const osg::Quat& getQuaternion() const;
         void setQuaternion(const osg::Quat&);
diff --git a/include/osgAnimation/StackedRotateAxisElement b/include/osgAnimation/StackedRotateAxisElement
index 7b5d47912..06a2278b8 100644
--- a/include/osgAnimation/StackedRotateAxisElement
+++ b/include/osgAnimation/StackedRotateAxisElement
@@ -36,7 +36,7 @@ namespace osgAnimation
         void applyToMatrix(osg::Matrix& matrix) const;
         osg::Matrix getAsMatrix() const;
         bool isIdentity() const { return (_angle == 0); }
-        void update();
+        void update(float t = 0.0);
 
         const osg::Vec3& getAxis() const;
         double getAngle() const;
diff --git a/include/osgAnimation/StackedScaleElement b/include/osgAnimation/StackedScaleElement
index a36cc5be3..6b49c3397 100644
--- a/include/osgAnimation/StackedScaleElement
+++ b/include/osgAnimation/StackedScaleElement
@@ -36,7 +36,7 @@ namespace osgAnimation
         void applyToMatrix(osg::Matrix& matrix) const;
         osg::Matrix getAsMatrix() const;
         bool isIdentity() const;
-        void update();
+        void update(float t = 0.0);
         const osg::Vec3& getScale() const;
         void setScale(const osg::Vec3& scale);
 
diff --git a/include/osgAnimation/StackedTransform b/include/osgAnimation/StackedTransform
index 59c1eed4f..367594a64 100644
--- a/include/osgAnimation/StackedTransform
+++ b/include/osgAnimation/StackedTransform
@@ -28,7 +28,7 @@ namespace osgAnimation
         StackedTransform();
         StackedTransform(const StackedTransform&, const osg::CopyOp& copyop = osg::CopyOp::SHALLOW_COPY);
 
-        void update();
+        void update(float t = 0.0);
         const osg::Matrix& getMatrix() const;
 
     protected:
diff --git a/include/osgAnimation/StackedTransformElement b/include/osgAnimation/StackedTransformElement
index 3a6628ff1..bdf441ddf 100644
--- a/include/osgAnimation/StackedTransformElement
+++ b/include/osgAnimation/StackedTransformElement
@@ -31,7 +31,7 @@ namespace osgAnimation
         virtual void applyToMatrix(osg::Matrix& matrix) const = 0;
         virtual osg::Matrix getAsMatrix() const = 0;
         virtual bool isIdentity() const = 0;
-        virtual void update() = 0;
+        virtual void update(float t) = 0;
         virtual Target* getOrCreateTarget() {return 0;}
         virtual Target* getTarget() {return 0;}
         virtual const Target* getTarget() const {return 0;}
diff --git a/include/osgAnimation/StackedTranslateElement b/include/osgAnimation/StackedTranslateElement
index 9728d0bee..bbc222d7a 100644
--- a/include/osgAnimation/StackedTranslateElement
+++ b/include/osgAnimation/StackedTranslateElement
@@ -36,7 +36,7 @@ namespace osgAnimation
         void applyToMatrix(osg::Matrix& matrix) const;
         osg::Matrix getAsMatrix() const;
         bool isIdentity() const;
-        void update();
+        void update(float t = 0.0);
 
         const osg::Vec3& getTranslate() const;
         void setTranslate(const osg::Vec3& );
diff --git a/src/osgAnimation/StackedMatrixElement.cpp b/src/osgAnimation/StackedMatrixElement.cpp
index 909ac26aa..4fd0dcac0 100644
--- a/src/osgAnimation/StackedMatrixElement.cpp
+++ b/src/osgAnimation/StackedMatrixElement.cpp
@@ -33,7 +33,7 @@ Target* StackedMatrixElement::getOrCreateTarget()
     return _target.get(); 
 }
 
-void StackedMatrixElement::update()
+void StackedMatrixElement::update(float t)
 {
     if (_target.valid())
         _matrix = _target->getValue();
diff --git a/src/osgAnimation/StackedQuaternionElement.cpp b/src/osgAnimation/StackedQuaternionElement.cpp
index c0fb89e24..a969ac51d 100644
--- a/src/osgAnimation/StackedQuaternionElement.cpp
+++ b/src/osgAnimation/StackedQuaternionElement.cpp
@@ -37,7 +37,7 @@ void StackedQuaternionElement::applyToMatrix(osg::Matrix& matrix) const {matrix.
 osg::Matrix StackedQuaternionElement::getAsMatrix() const { return osg::Matrix(_quaternion); }
 bool StackedQuaternionElement::isIdentity() const { return (_quaternion[0] == 0 && _quaternion[1] == 0 && _quaternion[2] == 0 && _quaternion[3] == 1.0); }
 
-void StackedQuaternionElement::update() 
+void StackedQuaternionElement::update(float t) 
 { 
     if (_target.valid())
         _quaternion = _target->getValue();
diff --git a/src/osgAnimation/StackedRotateAxisElement.cpp b/src/osgAnimation/StackedRotateAxisElement.cpp
index 2424da372..13e91267e 100644
--- a/src/osgAnimation/StackedRotateAxisElement.cpp
+++ b/src/osgAnimation/StackedRotateAxisElement.cpp
@@ -27,7 +27,7 @@ StackedRotateAxisElement::StackedRotateAxisElement(const StackedRotateAxisElemen
 
 
 osg::Matrix StackedRotateAxisElement::getAsMatrix() const { return osg::Matrix::rotate(osg::Quat(_angle, _axis)); }
-void StackedRotateAxisElement::update()
+void StackedRotateAxisElement::update(float t)
 { 
     if (_target.valid())
         _angle = _target->getValue();
diff --git a/src/osgAnimation/StackedScaleElement.cpp b/src/osgAnimation/StackedScaleElement.cpp
index 41b4dd837..3a7fe26ef 100644
--- a/src/osgAnimation/StackedScaleElement.cpp
+++ b/src/osgAnimation/StackedScaleElement.cpp
@@ -42,7 +42,7 @@ StackedScaleElement::StackedScaleElement()
     _scale = osg::Vec3(1,1,1);
 }
 
-void StackedScaleElement::update() 
+void StackedScaleElement::update(float t) 
 { 
     if (_target.valid())
         _scale = _target->getValue();
diff --git a/src/osgAnimation/StackedTransform.cpp b/src/osgAnimation/StackedTransform.cpp
index eda4d7d5c..de199b505 100644
--- a/src/osgAnimation/StackedTransform.cpp
+++ b/src/osgAnimation/StackedTransform.cpp
@@ -30,21 +30,21 @@ StackedTransform::StackedTransform(const StackedTransform& rhs, const osg::CopyO
 }
 
 
-void StackedTransform::update()
+void StackedTransform::update(float t)
 {
     int dirty = 0;
     for (StackedTransform::iterator it = begin(); it != end(); ++it)
     {
-        
         StackedTransformElement* element = it->get();
         if (!element)
             continue;
         // update and check if there are changes
-        element->update();
+        element->update(t);
         if (element->isIdentity())
             continue;
         dirty++;
     }
+
     if (!dirty)
         return;
 
diff --git a/src/osgAnimation/StackedTranslateElement.cpp b/src/osgAnimation/StackedTranslateElement.cpp
index f88710e11..7ac2d0415 100644
--- a/src/osgAnimation/StackedTranslateElement.cpp
+++ b/src/osgAnimation/StackedTranslateElement.cpp
@@ -43,7 +43,7 @@ Target* StackedTranslateElement::getOrCreateTarget()
 Target* StackedTranslateElement::getTarget() {return _target.get();}
 const Target* StackedTranslateElement::getTarget() const {return _target.get();}
 
-void StackedTranslateElement::update()
+void StackedTranslateElement::update(float t)
 {
     if (_target.valid())
         _translate = _target->getValue();