diff --git a/src/engine/DynamicsWorld.cpp b/src/engine/DynamicsWorld.cpp
index 927b28ee..242c8af9 100644
--- a/src/engine/DynamicsWorld.cpp
+++ b/src/engine/DynamicsWorld.cpp
@@ -142,9 +142,6 @@ void DynamicsWorld::update(decimal timeStep) {
 
     // Reset the external force and torque applied to the bodies
     resetBodiesForceAndTorque();
-
-    // Compute and set the interpolation factor to all the bodies
-    setInterpolationFactorToAllBodies();
 }
 
 // Integrate position and orientation of the rigid bodies.
diff --git a/src/engine/DynamicsWorld.h b/src/engine/DynamicsWorld.h
index bb0e9acb..482bc66e 100644
--- a/src/engine/DynamicsWorld.h
+++ b/src/engine/DynamicsWorld.h
@@ -186,12 +186,6 @@ class DynamicsWorld : public CollisionWorld {
         /// Destructor
         virtual ~DynamicsWorld();
 
-        /// Start the physics simulation
-        void start();
-
-        /// Stop the physics simulation
-        void stop();
-
         /// Update the physics simulation
         void update(decimal timeStep);
 
@@ -238,9 +232,6 @@ class DynamicsWorld : public CollisionWorld {
         /// Return the number of joints in the world
         uint getNbJoints() const;
 
-        /// Return the current physics time (in seconds)
-        long double getPhysicsTime() const;
-
         /// Return an iterator to the beginning of the rigid bodies of the physics world
         std::set<RigidBody*>::iterator getRigidBodiesBeginIterator();