diff --git a/simgear/scene/model/SGTranslateTransform.hxx b/simgear/scene/model/SGTranslateTransform.hxx
index be6ac0a7..d7de92c0 100644
--- a/simgear/scene/model/SGTranslateTransform.hxx
+++ b/simgear/scene/model/SGTranslateTransform.hxx
@@ -24,6 +24,9 @@
 
 #include <osg/Transform>
 #include <simgear/math/SGMath.hxx>
+#include <simgear/structure/SGSharedPtr.hxx>
+#include <simgear/structure/SGExpression.hxx>
+
 
 class SGTranslateTransform : public osg::Transform {
 public:
@@ -49,6 +52,9 @@ public:
                                          osg::NodeVisitor* nv) const;
   virtual osg::BoundingSphere computeBound() const;
 
+  // Only used for highlighting.
+  SGSharedPtr<SGExpressiond const> _animationValue;
+  
 private:
   SGVec3d _axis;
   double _value;
diff --git a/simgear/scene/model/animation.cxx b/simgear/scene/model/animation.cxx
index 95e0d003..a9ecaece 100644
--- a/simgear/scene/model/animation.cxx
+++ b/simgear/scene/model/animation.cxx
@@ -982,6 +982,7 @@ SGTranslateAnimation::createAnimationGroup(osg::Group& parent)
   if (_animationValue && !_animationValue->isConst()) {
     UpdateCallback* uc = new UpdateCallback(_condition, _animationValue);
     transform->setUpdateCallback(uc);
+    transform->_animationValue = _animationValue;
   }
   transform->setAxis(_axis);
   transform->setValue(_initialValue);
@@ -2494,3 +2495,16 @@ SGTexTransformAnimation::appendTexTrapezoid( const SGPropertyNode& cfg,
   trapezoid->setValue(cfg.getDoubleValue("starting-position", 0));
   updateCallback->appendTransform(trapezoid, readValue(cfg));
 }
+
+SGSharedPtr<SGExpressiond const> TransformExpression(osg::Transform* transform)
+{
+    SGSharedPtr<SGExpressiond const>    ret;
+    if (auto rot_anim_transform = dynamic_cast<SGRotAnimTransform*>(transform)) {
+        ret = rot_anim_transform->_animationValue;
+    }
+    else if (auto translate_transform = dynamic_cast<SGTranslateTransform*>(transform)) {
+        ret = translate_transform->_animationValue;
+    }
+    return ret;
+}
+
diff --git a/simgear/scene/model/animation.hxx b/simgear/scene/model/animation.hxx
index 51174cb1..5826b9ba 100644
--- a/simgear/scene/model/animation.hxx
+++ b/simgear/scene/model/animation.hxx
@@ -38,6 +38,11 @@ read_value(const SGPropertyNode* configNode, SGPropertyNode* modelRoot,
 
 SGVec3d readTranslateAxis(const SGPropertyNode* configNode);
 
+/**
+ * Returns transform's expression if it has one.
+ */
+SGSharedPtr<SGExpressiond const> TransformExpression(osg::Transform* transform);
+
 /**
  * Base class for animation installers
  */