diff --git a/src/fgt/filter_physics/DynamicMeshSubFilter.cpp b/src/fgt/filter_physics/DynamicMeshSubFilter.cpp
index 214510bd1..b32b52da1 100644
--- a/src/fgt/filter_physics/DynamicMeshSubFilter.cpp
+++ b/src/fgt/filter_physics/DynamicMeshSubFilter.cpp
@@ -1,5 +1,7 @@
 #include "DynamicMeshSubFilter.h"
 
+#include <vcg/complex/trimesh/append.h>
+
 DynamicMeshSubFilter::DynamicMeshSubFilter() : m_steps(-1), m_seconds(-1) {
 }
 
@@ -20,10 +22,54 @@ bool DynamicMeshSubFilter::applyFilter(QAction* filter, MeshDocument &md, RichPa
 
 bool DynamicMeshSubFilter::configurationHasChanged(MeshDocument& md, RichParameterSet& par){
     bool changed = m_seconds != par.getInt("seconds");
+
+    // Does not work because meshlab fails at restoring the original translation matrix in the preview checkbox logic
+    /* Dim: the transformation matrices should not change
+    for(int i = 0; i < md.size(); i++){
+        for(int j = 0; j < 16; j++) std::cout << md.getMesh(i)->cm.Tr[j/4][j%4] <<" ";
+        std::cout<<std::endl;
+    }
+    */
+
+    /*if(md.size() == m_state.size()){
+        for(int i = 0; i < m_state.size() && !changed; i++){
+            changed |= !compareMesh(md.getMesh(i), m_state[i]);
+        }
+    }else
+        changed = true;
+
+    saveMeshState(md);*/
+
+    // Old correctness testing
+    /*if(md.size() == m_files.size())
+        for(int i = 0; i < m_files.size(); i++)
+            changed |= m_files.at(i) != md.getMesh(i)->fileName;
+    else
+        changed = true;
+
+    m_files.clear();
+    for(int i = 0; i < md.size(); i++)
+        m_files.push_back(md.getMesh(i)->fileName);*/
+
     m_seconds = par.getInt("seconds");
     return changed;
 }
 
+bool DynamicMeshSubFilter::compareMesh(MeshModel* m1, MeshModel* m2){
+    return m1->fileName == m2->fileName && m1->cm.Tr == m2->cm.Tr;
+}
+
+void DynamicMeshSubFilter::saveMeshState(MeshDocument& md){
+    m_state.clear();
+    for(int i = 0; i < md.size(); i++){
+        MeshModel* meshCopy = new MeshModel();
+        vcg::tri::Append<CMeshO,CMeshO>::Mesh(meshCopy->cm, md.getMesh(i)->cm, false, true);
+        meshCopy->fileName = md.getMesh(i)->fileName;
+        meshCopy->cm.Tr = md.getMesh(i)->cm.Tr;
+        m_state.push_back(meshCopy);
+    }
+}
+
 void DynamicMeshSubFilter::initialize(MeshDocument&, RichParameterSet&, vcg::CallBackPos* cb){
     m_steps = m_seconds / m_stepSize;
 }
diff --git a/src/fgt/filter_physics/DynamicMeshSubFilter.h b/src/fgt/filter_physics/DynamicMeshSubFilter.h
index e4da68db7..f8311ef22 100644
--- a/src/fgt/filter_physics/DynamicMeshSubFilter.h
+++ b/src/fgt/filter_physics/DynamicMeshSubFilter.h
@@ -20,10 +20,16 @@ protected:
 
     virtual void initialize(MeshDocument&, RichParameterSet&, vcg::CallBackPos* cb);
     virtual bool configurationHasChanged(MeshDocument& md, RichParameterSet& par);
+    void saveMeshState(MeshDocument& md);
 
     int m_steps;
     int m_seconds;
     LayersTransformations m_layersTrans;
+    std::vector<std::string> m_files;
+    std::vector<MeshModel*> m_state;
+
+private:
+    bool compareMesh(MeshModel* m1, MeshModel* m2);
 };
 
 #endif // DYNAMICMESHSUBFILTER_H
diff --git a/src/fgt/filter_physics/GravitySubFilter.cpp b/src/fgt/filter_physics/GravitySubFilter.cpp
index dcb50c5bb..3a2edb653 100644
--- a/src/fgt/filter_physics/GravitySubFilter.cpp
+++ b/src/fgt/filter_physics/GravitySubFilter.cpp
@@ -1,6 +1,10 @@
 #include "GravitySubFilter.h"
 
+int GravitySubFilter::m_filterType = -1;
+
 GravitySubFilter::GravitySubFilter() : m_scenery(0){
+    MeshSubFilter::m_currentFilterType += 1;
+    m_filterType = MeshSubFilter::m_currentFilterType;
 }
 
 void GravitySubFilter::initParameterSet(QAction* action,MeshDocument& md, RichParameterSet& par){
@@ -24,8 +28,9 @@ bool GravitySubFilter::applyFilter(QAction* filter, MeshDocument &md, RichParame
 }
 
 bool GravitySubFilter::configurationHasChanged(MeshDocument& md, RichParameterSet& par){
-    bool changed = DynamicMeshSubFilter::configurationHasChanged(md, par) || m_scenery != par.getMesh("scenery");
+    bool changed = DynamicMeshSubFilter::configurationHasChanged(md, par) || m_scenery != par.getMesh("scenery") || m_currentFilterType != m_filterType;
     m_scenery = par.getMesh("scenery");
+    m_currentFilterType = m_filterType;
     return changed;
 }
 
diff --git a/src/fgt/filter_physics/GravitySubFilter.h b/src/fgt/filter_physics/GravitySubFilter.h
index 937fe39b4..c00349666 100644
--- a/src/fgt/filter_physics/GravitySubFilter.h
+++ b/src/fgt/filter_physics/GravitySubFilter.h
@@ -22,6 +22,8 @@ protected:
 private:
     MeshModel* m_scenery;
     ODEFacade m_engine;
+
+    static int m_filterType;
 };
 
 #endif // GRAVITYSUBFILTER_H
diff --git a/src/fgt/filter_physics/MeshSubFilter.cpp b/src/fgt/filter_physics/MeshSubFilter.cpp
index 221239001..5192477bf 100644
--- a/src/fgt/filter_physics/MeshSubFilter.cpp
+++ b/src/fgt/filter_physics/MeshSubFilter.cpp
@@ -2,3 +2,5 @@
 
 const float MeshSubFilter::m_stepSize = 0.02;
 const unsigned int MeshSubFilter::m_stepsPerSecond = 1.0f/m_stepSize;
+//MeshSubFilter::FilterType MeshSubFilter::m_currentFilterType = FILTERTYPE_UNDEFINED;
+int MeshSubFilter::m_currentFilterType = 0;
diff --git a/src/fgt/filter_physics/MeshSubFilter.h b/src/fgt/filter_physics/MeshSubFilter.h
index dc035d354..0404186f9 100644
--- a/src/fgt/filter_physics/MeshSubFilter.h
+++ b/src/fgt/filter_physics/MeshSubFilter.h
@@ -14,10 +14,11 @@ public:
     virtual bool applyFilter(QAction* filter, MeshDocument &md, RichParameterSet& par, vcg::CallBackPos* cb) = 0;
 
 protected:
-    enum SubType{ GRAVITY, RANDOMDROP, RANDOMFILL };
+    enum FilterType{ FILTERTYPE_UNDEFINED, FILTERTYPE_GRAVITY, FILTERTYPE_RANDOMDROP, FILTERTYPE_RANDOMFILL };
 
     static const float m_stepSize;
     static const unsigned int m_stepsPerSecond;
+    static int m_currentFilterType;
 };
 
 #endif // MESHSUBFILTER_H
diff --git a/src/fgt/filter_physics/ODEFacade.cpp b/src/fgt/filter_physics/ODEFacade.cpp
index a967bc216..572a83303 100644
--- a/src/fgt/filter_physics/ODEFacade.cpp
+++ b/src/fgt/filter_physics/ODEFacade.cpp
@@ -103,7 +103,8 @@ void ODEFacade::setAsRigidBody(MeshModel& mesh, bool isRigidBody){
         dMassSetParameters(&m_registeredMeshes[index()].second->mass, inertia.Mass() > 0.f ? inertia.Mass() : 1.f,
                            inertia.CenterOfMass()[0], inertia.CenterOfMass()[1], inertia.CenterOfMass()[2],
                            IT[0][0], IT[1][1], IT[2][2], IT[0][1], IT[0][2], IT[1][2]);
-        dBodySetMass(m_registeredMeshes[index()].second->body, &m_registeredMeshes[index()].second->mass);
+        //For now it is best to let ODE do the job automatically
+        //dBodySetMass(m_registeredMeshes[index()].second->body, &m_registeredMeshes[index()].second->mass);
 
     }
 
diff --git a/src/fgt/filter_physics/RandomDropFilter.cpp b/src/fgt/filter_physics/RandomDropFilter.cpp
index ae7fce526..ae79f3257 100644
--- a/src/fgt/filter_physics/RandomDropFilter.cpp
+++ b/src/fgt/filter_physics/RandomDropFilter.cpp
@@ -8,7 +8,11 @@
 
 using namespace std;
 
+int RandomDropFilter::m_filterType = -1;
+
 RandomDropFilter::RandomDropFilter() : m_randomMesh(0), m_dropRate(-1), m_distance(-1){
+    MeshSubFilter::m_currentFilterType += 1;
+    m_filterType = MeshSubFilter::m_currentFilterType;
 }
 
 void RandomDropFilter::initParameterSet(QAction* action,MeshDocument& md, RichParameterSet & par){
@@ -93,6 +97,11 @@ void RandomDropFilter::initialize(MeshDocument& md, RichParameterSet& par, vcg::
         m_engine.integrate(m_stepSize);
     }
 
+    /* Was need for old correctness testing
+    m_files.clear();
+    for(int i = 0; i < md.size(); i++)
+        m_files.push_back(md.getMesh(i)->fileName);*/
+
     if(cb != 0) (*cb)(99, "Physics pre-renderization of the scene completed...");
 }
 
@@ -116,11 +125,13 @@ bool RandomDropFilter::configurationHasChanged(MeshDocument& md, RichParameterSe
     bool changed = DynamicMeshSubFilter::configurationHasChanged(md, par) ||
                    m_randomMesh != par.getMesh("randomMesh") ||
                    m_distance != par.getFloat("distance") ||
-                   m_dropRate != par.getInt("dropRate");
+                   m_dropRate != par.getInt("dropRate") ||
+                   m_currentFilterType != m_filterType;
 
     m_randomMesh = par.getMesh("randomMesh");
     m_distance = par.getFloat("distance");
     m_dropRate = par.getInt("dropRate");
+    m_currentFilterType = m_filterType;
 
     return changed;
 }
diff --git a/src/fgt/filter_physics/RandomDropFilter.h b/src/fgt/filter_physics/RandomDropFilter.h
index de89d792b..b1592db4b 100644
--- a/src/fgt/filter_physics/RandomDropFilter.h
+++ b/src/fgt/filter_physics/RandomDropFilter.h
@@ -25,6 +25,8 @@ private:
     int m_dropRate;
     float m_distance;
     ODEFacade m_engine;
+
+    static int m_filterType;
 };
 
 #endif // RANDOMDROPFILTER_H
diff --git a/src/fgt/filter_physics/RandomFillFilter.cpp b/src/fgt/filter_physics/RandomFillFilter.cpp
index 090b87366..8e94caa4f 100644
--- a/src/fgt/filter_physics/RandomFillFilter.cpp
+++ b/src/fgt/filter_physics/RandomFillFilter.cpp
@@ -8,6 +8,13 @@
 using namespace std;
 using namespace vcg;
 
+int RandomFillFilter::m_filterType = -1;
+
+RandomFillFilter::RandomFillFilter(){
+    MeshSubFilter::m_currentFilterType += 1;
+    m_filterType = MeshSubFilter::m_currentFilterType;
+}
+
 void RandomFillFilter::initParameterSet(QAction* action,MeshDocument& md, RichParameterSet & par){
     par.addParam(new RichMesh("container", 0, &md, "Container mesh", "This mesh will act as a container for the filling mesh"));
     par.addParam(new RichMesh("filler", 0, &md, "Filler mesh", "The container mesh will be filled with this mesh"));
diff --git a/src/fgt/filter_physics/RandomFillFilter.h b/src/fgt/filter_physics/RandomFillFilter.h
index 0c82ac835..3e86a347d 100644
--- a/src/fgt/filter_physics/RandomFillFilter.h
+++ b/src/fgt/filter_physics/RandomFillFilter.h
@@ -8,6 +8,8 @@
 
 class RandomFillFilter : public MeshSubFilter{
 public:
+    RandomFillFilter();
+
     virtual void initParameterSet(QAction* action,MeshDocument& md, RichParameterSet & par);
     virtual bool applyFilter(QAction* filter, MeshDocument &md, RichParameterSet& par, vcg::CallBackPos* cb);
 
@@ -17,6 +19,8 @@ protected:
 private:
     int m_dropRate;
     ODEFacade m_engine;
+
+    static int m_filterType;
 };
 
 #endif // RANDOMFILLFILTER_H