diff --git a/src/fgt/filter_dirt/dirt_utils.h b/src/fgt/filter_dirt/dirt_utils.h
index 645d85b16..905f56101 100644
--- a/src/fgt/filter_dirt/dirt_utils.h
+++ b/src/fgt/filter_dirt/dirt_utils.h
@@ -23,9 +23,9 @@
 #ifndef DIRT_UTILS_H
 #define DIRT_UTILS_H
 
-#define PI 3.14159265
-//Include Files
+#define PI 3.14159265 //To delete?
 
+//Include Files
 #include <math.h>
 #include <common/meshmodel.h>
 #include <common/interfaces.h>
@@ -42,7 +42,14 @@
 using namespace vcg;
 using namespace tri;
 
+/**
+@def This funcion calculate the cartesian coordinates of a point given from its barycentric coordinates
 
+@param Point3f bc       - barycentric coordinates of the point
+@param FacePointer f    - pointer to the face
+
+@return cartesian coordinates of the point
+*/
 CMeshO::CoordType fromBarCoords(Point3f bc,CMeshO::FacePointer f){
 
     CMeshO::CoordType p;
@@ -55,8 +62,10 @@ CMeshO::CoordType fromBarCoords(Point3f bc,CMeshO::FacePointer f){
     return p;
 };
 
-
-CMeshO::CoordType CoordinateCorrection(CMeshO::CoordType p,CMeshO::FacePointer f){
+/**
+@def
+*/
+CMeshO::CoordType fixEdgePointCoordinates(CMeshO::CoordType p,CMeshO::FacePointer f){
     Point3f bc;
     CMeshO::CoordType c_p; //Correct Position
     InterpolationParameters(*f,p,bc);
@@ -81,15 +90,6 @@ CMeshO::CoordType CoordinateCorrection(CMeshO::CoordType p,CMeshO::FacePointer f
     return c_p;
 };
 
-bool SameSide(Point3f p1,Point3f p2,Point3f a,Point3f b){
-        Point3f cp1;
-        Point3f cp2;
-        cp1 = (b-a)^(p1-a);
-        cp2 = (b-a)^(p2-a);
-        if (cp1.dot(cp2) >= 0) return true;
-        else return false;
-
-};
 
 /**
 @def Verify if a point lies on a face
@@ -100,190 +100,7 @@ bool SameSide(Point3f p1,Point3f p2,Point3f a,Point3f b){
 @return true if point p is on face f, false elsewhere.
 */
 bool IsOnFace(Point3f p, CMeshO::FacePointer f){
-    //Verify if the point is on the same plane of the face
-
-
-    CMeshO::CoordType n=f->N();
-
-    Point3f a=f->P(0);
-    if(math::Abs((p-a).dot(n))>0.0005) return false;
-
-
-
-    //Point3f bc;
-    //isOnFace=InterpolationParameters(*f,vcg::Normal(*f),p,bc);
-
-    //if(isOnFace && bc[0]>=0 && bc[1]>=0 && (bc[0]+bc[1]<=1)) return true;
-
-
-    //Point3f a=f->P(0);
-    //float tmp2=n.dot(p);
-    //float tmp=n.dot(a);
-    //if(math::Abs(tmp2-tmp)>0.01) return false;
-    //Point3f v0 = (f->V(0))->P();
-    //Point3f v1 = (f->V(1))->P();
-    //Point3f v2 = (f->V(2))->P();
-
-
- //  if(SameSide(p,v0,v1,v2) && SameSide(p,v1,v0,v2) && SameSide(p,v2,v0,v1)) return true;
-  //  return false;
-/*
-    //Compute Barycentric coordinates
-    Point3f bc;
-    bool isOnFace=false;
-    isOnFace=InterpolationParameters(*f,vcg::Normal(*f),p,bc);
-    if(!isOnFace) return false;
-    isOnFace=(bc[0]>=0 && bc[1]>=0) && (bc[0]+bc[1] < 1);
-    return isOnFace;
-*/
-   /*
-
-    CMeshO::CoordType n=f->N();
-    Point3f a=f->P(0);
-    float tmp2=n.dot(p);
-    float tmp=n.dot(a);
-    if(math::Abs(tmp2-tmp)>0.001) return false;
-*/
-
-/*
-    int max_c;
-
-    if(math::Abs(n[0])>math::Abs(n[1])){
-          if(math::Abs(n[0])>math::Abs(n[2])) max_c=0;
-          else max_c=2;
-    }else{
-        if(math::Abs(n[1])>math::Abs(n[2])) max_c=1;
-        else max_c=2;
-              }
-
-
-    CMeshO::CoordType fv0 = (f->V(0))->P();
-    CMeshO::CoordType fv1 = (f->V(1))->P();
-    CMeshO::CoordType fv2 = (f->V(2))->P();
-    Point2<float> A;
-    Point2<float> B;
-    Point2<float> C;
-    Point2<float> P;
-    switch(max_c){
-
-      case 0:{
-            A=Point2f(fv0[1],fv0[2]);
-            B=Point2f(fv1[1],fv1[2]);
-            C=Point2f(fv2[1],fv2[2]);
-            P=Point2f(p[1],p[2]);
-            break;
-        }
-
-    case 1:{
-            A=Point2f(fv0[0],fv0[2]);
-            B=Point2f(fv1[0],fv1[2]);
-            C=Point2f(fv2[0],fv2[2]);
-            P=Point2f(p[0],p[2]);
-            break;
-        }
-
-    case 2:{
-            A=Point2f(fv0[0],fv0[1]);
-            B=Point2f(fv1[0],fv1[1]);
-            C=Point2f(fv2[0],fv2[1]);
-            P=Point2f(p[0],p[1]);
-        break;
-        }
-    }
-*/
-
-
-/*
-    Point3f A=f->V(0)->P();
-    Point3f B=f->V(1)->P();
-    Point3f C=f->V(2)->P();
-
-    Point3fv0 = C - A;
-    Point3fv1 = B - A;
-    Point3fv2 = p - A;
-
-    // Compute dot products
-    double dot00 = v0.dot(v0);
-    double dot01 = v0.dot(v1);
-    double dot02 = v0.dot(v2);
-    double dot11 = v1.dot(v1);
-    double dot12 = v1.dot(v2);
-
-    // Compute barycentric coordinates
-    double invDenom = 1 / (dot00 * dot11 - dot01 * dot01);
-    double u = (dot11 * dot02 - dot01 * dot12) * invDenom;
-    double v = (dot00 * dot12 - dot01 * dot02) * invDenom;
-
-    // Check if point is in triangle
-    //Compute Barycentric coordinates
-    Point3f bc;
-
-    InterpolationParameters(*f,vcg::Normal(*f),p,bc);
-
-    bool isOnFace=(u >= 0) && (v >= 0) && (u + v <= 1.00001);
-    return isOnFace;
-*/
-
-
-
-
-
-    int max_c;
-
-    float n0=math::Abs(n[0]);
-    float n1=math::Abs(n[1]);
-    float n2=math::Abs(n[2]);
-
-    if(n0>n1){
-          if(n0>n2) max_c=0;
-          else max_c=2;
-    }else{
-        if(n1>n2) max_c=1;
-        else max_c=2;
-              }
-
-
-    Point2f p_2d;
-    Point2f p0_2d;
-    Point2f p1_2d;
-    Point2f p2_2d;
-
-    CMeshO::CoordType p0 = f->P(0);
-    CMeshO::CoordType p1 = f->P(1);
-    CMeshO::CoordType p2 = f->P(2);
-    switch(max_c){
-    case 0:{
-            p0_2d=Point2f(p0[1],p0[2]);
-            p1_2d=Point2f(p1[1],p1[2]);
-            p2_2d=Point2f(p2[1],p2[2]);
-            p_2d =Point2f(p[1],p[2]);
-            break;
-        }
-    case 1:{
-            p0_2d=Point2f(p0[0],p0[2]);
-            p1_2d=Point2f(p1[0],p1[2]);
-            p2_2d=Point2f(p2[0],p2[2]);
-            p_2d =Point2f(p[0],p[2]);
-
-            break;
-        }
-    case 2:{
-            p0_2d=Point2f(p0[0],p0[1]);
-            p1_2d=Point2f(p1[0],p1[1]);
-            p2_2d=Point2f(p2[0],p2[1]);
-            p_2d =Point2f(p[0],p[1]);
-
-            break;
-        }
-    }
-
-
-
-
     Triangle2<float> f_2d=Triangle2<float>(p0_2d,p1_2d,p2_2d);
-
-
-
     return IsInsideTrianglePoint(f_2d,p_2d);
 
 };
@@ -330,10 +147,7 @@ float getElapsedTime(CMeshO::CoordType vi,CMeshO::CoordType vf,CMeshO::FacePoint
     return t;
 };
 
-/**
-@def
 
-*/
 bool IsOnEdge(CMeshO::CoordType p,CMeshO::FacePointer f){
     if(f==0) return false;
     float bc[3];
@@ -343,6 +157,60 @@ bool IsOnEdge(CMeshO::CoordType p,CMeshO::FacePointer f){
     return false;
 };
 
+
+CMeshO::CoordType ComputeVelocity(CMeshO::CoordType vi,CMeshO::CoordType ac,float t){
+
+    CMeshO::CoordType n_vel;
+
+    n_vel[0]=vi[0]+ac[0]*t;
+    n_vel[1]=vi[1]+ac[1]*t;
+    n_vel[2]=vi[2]+ac[2]*t;
+
+    return n_vel;
+};
+CMeshO::CoordType UpdateVelocity(CMeshO::CoordType pf,CMeshO::CoordType pi,CMeshO::CoordType v,float m,CMeshO::FacePointer &face,CMeshO::CoordType force){
+
+    CMeshO::CoordType new_vel;
+    Point3f n= face->cN();
+    float a=n[0]*force[0]+n[1]*force[1]+n[2]*force[2];
+    //float b=n[0]*vel[0]+n[1]*vel[1]+n[2]*vel[2];
+
+    Point3f f;
+    //Point3f v;
+
+    f[0]=force[0]-a*n[0];
+    f[1]=force[1]-a*n[1];
+    f[2]=force[2]-a*n[2];
+
+
+    //v[0]=vel[0]-b*n[0];
+    //v[1]=vel[1]-b*n[1];
+    //v[2]=vel[2]-b*n[2];
+
+    new_vel[0]=sqrt(pow(v[0],2)+2*(f[0]/m)*(pf[0]-pi[0]) );
+    new_vel[1]=sqrt(pow(v[1],2)+2*(f[1]/m)*(pf[1]-pi[1]) );
+    new_vel[2]=sqrt(pow(v[2],2)+2*(f[2]/m)*(pf[2]-pi[2]) );
+
+
+    return new_vel;
+};
+CMeshO::CoordType ComputeAcceleration(float m,CMeshO::FacePointer face,CMeshO::CoordType dir){
+    CMeshO::CoordType acc;
+
+    Point3f n= face->N();
+    float a=n[0]*dir[0]+n[1]*dir[1]+n[2]*dir[2];
+
+    acc[0]=dir[0]-a*n[0];
+    acc[1]=dir[1]-a*n[1];
+    acc[2]=dir[2]-a*n[2];
+
+    return acc;
+};
+
+
+/**
+@def
+*/
 CMeshO::CoordType GetVelocityComponents(float v,float l,CMeshO::FacePointer face){
 
     Point3f dir = Point3f(0,-1,0);
@@ -382,58 +250,9 @@ CMeshO::CoordType GetVelocityComponents(float v,float l,CMeshO::FacePointer face
 
 };
 
-CMeshO::CoordType ComputeVelocity(CMeshO::CoordType vi,CMeshO::CoordType ac,float t){
-
-    CMeshO::CoordType n_vel;
-
-    n_vel[0]=vi[0]+ac[0]*t;
-    n_vel[1]=vi[1]+ac[1]*t;
-    n_vel[2]=vi[2]+ac[2]*t;
-
-    return n_vel;
-};
-CMeshO::CoordType UpdateVelocity(CMeshO::CoordType pf,CMeshO::CoordType pi,CMeshO::CoordType v,float m,CMeshO::FacePointer &face,CMeshO::CoordType force){
-
-    CMeshO::CoordType new_vel;
-    Point3f n= face->cN();
-    float a=n[0]*force[0]+n[1]*force[1]+n[2]*force[2];
-    //float b=n[0]*vel[0]+n[1]*vel[1]+n[2]*vel[2];
-
-    Point3f f;
-    //Point3f v;
-
-    f[0]=force[0]-a*n[0];
-    f[1]=force[1]-a*n[1];
-    f[2]=force[2]-a*n[2];
-
-
-    //v[0]=vel[0]-b*n[0];
-    //v[1]=vel[1]-b*n[1];
-    //v[2]=vel[2]-b*n[2];
-
-    new_vel[0]=sqrt(pow(v[0],2)+2*(f[0]/m)*(pf[0]-pi[0]) );
-    new_vel[1]=sqrt(pow(v[1],2)+2*(f[1]/m)*(pf[1]-pi[1]) );
-    new_vel[2]=sqrt(pow(v[2],2)+2*(f[2]/m)*(pf[2]-pi[2]) );
-
-
-    return new_vel;
-};
-
-CMeshO::CoordType ComputeAcceleration(float m,CMeshO::FacePointer face,CMeshO::CoordType dir){
-    CMeshO::CoordType acc;
-
-    Point3f n= face->N();
-    float a=n[0]*dir[0]+n[1]*dir[1]+n[2]*dir[2];
-
-    acc[0]=dir[0]-a*n[0];
-    acc[1]=dir[1]-a*n[1];
-    acc[2]=dir[2]-a*n[2];
-
-    return acc;
-};
 
 /**
-  @description Simulate the movement of a point, affected by a force "dir" on a face.
+  @def Simulate the movement of a point, affected by a force "dir" on a face.
 
   @param CoordType p   - coordinates of the point
   @param CoordType v   - velocity of the particle
@@ -444,36 +263,23 @@ CMeshO::CoordType ComputeAcceleration(float m,CMeshO::FacePointer face,CMeshO::C
 
   @return new coordinates of the point
 */
-CMeshO::CoordType StepForward(CMeshO::CoordType p,
-                              float v,
-                              float m,
-                              CMeshO::FacePointer &face,
-                              CMeshO::CoordType dir,float l,
-                              float t=1){
-
-   /* if(v<0.005 && IsOnEdge(p,face))
-        return p;
-    */
-
-
+CMeshO::CoordType StepForward(CMeshO::CoordType p,float v,float m,CMeshO::FacePointer &face,CMeshO::CoordType dir,float l,float t=1){
 
     dir=dir*l;
     Point3f new_pos;
     Point3f n= face->N();
     float a=n[0]*dir[0]+n[1]*dir[1]+n[2]*dir[2];
 
-//    float b=n[0]*vel[0]+n[1]*vel[1]+n[2]*vel[2];
-
 
 
     Point3f f;
     Point3f vel=GetVelocityComponents(v,l,face);
-    //Calcolo le componenti della forza lungo la faccia
+
+    //Compute force component along the face
     f[0]=dir[0]-a*n[0];
     f[1]=dir[1]-a*n[1];
     f[2]=dir[2]-a*n[2];
 
-
     new_pos[0]=p[0]+vel[0]*t+0.5*(f[0]/m)*pow(t,2);
     new_pos[1]=p[1]+vel[1]*t+0.5*(f[1]/m)*pow(t,2);
     new_pos[2]=p[2]+vel[2]*t+0.5*(f[2]/m)*pow(t,2);
@@ -503,7 +309,8 @@ void DrawDirt(MeshModel *m/*,std::vector<Point3f> &dp*/){
 @param CoordType int_point - intersection point this is a return parameter for the function.
 @param FacePointer face - pointer to the new face
 
-@return true if there is an intersection
+@return true if there is an intersection, false elsewhere
+
 */
 bool ComputeIntersection(CMeshO::CoordType p1,CMeshO::CoordType p2,CMeshO::FacePointer &f,CMeshO::FacePointer &new_f,CMeshO::CoordType &int_point)
 {
@@ -569,8 +376,9 @@ bool ComputeIntersection(CMeshO::CoordType p1,CMeshO::CoordType p2,CMeshO::FaceP
 
     Point2f tmp_int;
     bool int_found=false;
-    int edge;
+    int edge=-1;
     float dist=0;
+
     if(LineSegmentIntersection(seg,line0,tmp_int)){
         dist=Distance(p2_2d,tmp_int);
         edge=0;
@@ -616,76 +424,6 @@ bool ComputeIntersection(CMeshO::CoordType p1,CMeshO::CoordType p2,CMeshO::FaceP
 
 
 
-
-    if(!int_found){
-        Point3f bc;
-        InterpolationParameters(*f,f->N(),p1,bc);
-        int p=1;
-    }
-
-    /*
-    if(SegmentSegmentIntersection(line0,seg,tmp)){
-        if(tmp!=p1_2d){
-            int_p=tmp;
-            edge=0;
-            int_found=true;
-        }
-     }
-        if(SegmentSegmentIntersection(line1,seg,tmp)){
-            if(tmp!=p1_2d){
-                int_p =tmp;
-                edge=1;
-                int_found=true;
-            }
-        }
-        if(SegmentSegmentIntersection(line2,seg,tmp)){
-            if(tmp!=p1_2d){
-                int_p =tmp;
-                edge=2;
-                int_found=true;
-            }
-        }
-    */
-
-    /*
-    bool int_found=false;
-    int edge=-1;
-    Point2f tmp;
-    if(SegmentSegmentIntersection(line0,seg,tmp)){
-       int_found=true;
-       int_p=tmp;
-       edge=0;
-    }
-    if(SegmentSegmentIntersection(line1,seg,tmp)){
-        if(int_found){
-
-            if(Segment2f(tmp,p2_2d).Length()<Segment2f(int_p,p2_2d).Length()){
-            int_found=true;
-            int_p=tmp;
-            edge=1;
-            }
-        }else{
-            int_found=true;
-            int_p=tmp;
-            edge=1;
-        }
-    }
-    if(SegmentSegmentIntersection(line2,seg,tmp)){
-        if(int_found){
-            if(Segment2f(tmp,p2_2d).Length()<Segment2f(int_p,p2_2d).Length()){
-            int_found=true;
-            int_p=tmp;
-            edge=2;
-            }
-        }else{
-            int_found=true;
-            int_p=tmp;
-            edge=2;
-        }
-    }
-
-    */
-
     if(int_found){
         new_f=f->FFp(edge);
         switch(max_c){
@@ -708,69 +446,21 @@ bool ComputeIntersection(CMeshO::CoordType p1,CMeshO::CoordType p2,CMeshO::FaceP
                 break;
               }
           }
-    }
 
-    /*      if(int_found){
-       Point3f bc;
-       InterpolationParameters(*new_f,new_f->N(),int_point,bc);
-       int min_c;
-
-       if(bc[0]<bc[1]){
-           if(bc[0]<bc[2]){
-            min_c=0;
-           }else{
-            min_c=2;
-           }
-        }else{
-            if(bc[1]<bc[2]){
-            min_c=1;
-            }else{
-             min_c=2;
-            }
-                }
-
-        switch(edge){
-
-        case 0:{
-            bc[0]=0;
-            bc[1]=bc[1];
-            bc[2]=1-bc[1]-0.0001;
-            break;
-            }
-        case 1:{
-                bc[0]=bc[0];
-                bc[1]=0;
-                bc[2]=1-bc[0]-0.0001;
-                break;
-            }
-        case 2:{
-                bc[0]=bc[0];
-                bc[1]=1-bc[0]-0.0001;
-                bc[2]=0;
-                break;
-            }
+        if(!IsOnFace(int_point,new_face)){
+            int_point=fixEdgePointCoordinates(int_point,new_f);
         }
 
-
-        Point3f nf0=new_f->P(0);
-        Point3f nf1=new_f->P(1);
-        Point3f nf2=new_f->P(2);
-        int_point[0]=nf0[0]*bc[0]+nf1[0]*bc[1]+nf2[0]*bc[2];
-        int_point[1]=nf0[1]*bc[0]+nf1[1]*bc[1]+nf2[1]*bc[2];
-        int_point[2]=nf0[2]*bc[0]+nf1[2]*bc[1]+nf2[2]*bc[2];
-
     }
-*/
-
     return int_found;
 };
 
 /**
-@description generate random baricentric coordinates
+@def Generate random barycentric coordinates
+@return a triple of barycentri coordinates
 */
 CMeshO::CoordType RandomBaricentric(){
     CMeshO::CoordType interp;
-
     static math::MarsenneTwisterRNG rnd;
     interp[1] = rnd.generate01();
     interp[2] = rnd.generate01();
@@ -792,13 +482,10 @@ CMeshO::CoordType RandomBaricentric(){
 @param u CoordType dust direction
 @param k float
 @param s float
+
+@return nothing
 */
-bool ComputeNormalDustAmount(MeshModel* m,CMeshO::CoordType u,float k,float s){
-
-    //Verify if FaceQualty is enabled
-
-
-
+void ComputeNormalDustAmount(MeshModel* m,CMeshO::CoordType u,float k,float s){
 
     CMeshO::FaceIterator fi;
     float d;
@@ -811,12 +498,13 @@ bool ComputeNormalDustAmount(MeshModel* m,CMeshO::CoordType u,float k,float s){
 };
 
 /**
-@description This function compute the Surface Exposure per face of a Mesh m
+@def This function compute the Surface Exposure per face of a Mesh m
 
 @param  MeshModel* m - Pointer to the new mesh
 @param int r - scaling factor
 @param int n_ray - number of rays emitted
 
+@return nothing
 */
 void ComputeSurfaceExposure(MeshModel* m,int r,int n_ray){
     CMeshO::FaceIterator fi;
@@ -877,6 +565,8 @@ void ComputeSurfaceExposure(MeshModel* m,int r,int n_ray){
 
 };
 
+
+//To delete?
 void CreateDustTexture(MeshModel* m){
     QString textName="dust_texture";
     QString fileName(m->fullName());
@@ -891,7 +581,7 @@ void CreateDustTexture(MeshModel* m){
 }
 
 /**
-@def
+@def This funcion
 
 @param
 @param
@@ -950,11 +640,9 @@ return true;
 };
 
 
+/**
 
-
-
-
-
+*/
 void associateParticles(MeshModel* b_m,MeshModel* c_m,float m,float v){
     CMeshO::PerVertexAttributeHandle<Particle<CMeshO> > ph= tri::Allocator<CMeshO>::AddPerVertexAttribute<Particle<CMeshO> > (c_m->cm,std::string("ParticleInfo"));
     CMeshO::FaceIterator fi;
@@ -974,7 +662,13 @@ void associateParticles(MeshModel* b_m,MeshModel* c_m,float m,float v){
 };
 
 
+/**
+@def This function initialize the mesh m in order to respect some prerequisites of the filter
 
+@param MeshModel* m - Pointer to the Mesh
+
+@return nothing
+*/
 void prepareMesh(MeshModel* m){
     //clean flags
 
@@ -1004,63 +698,52 @@ void prepareMesh(MeshModel* m){
 
 }
 
+/**
+@def This function simulate the movement of the cloud mesh, it requires that every point is associated with a Particle data structure
 
-bool MoveCloudMeshForward(MeshModel *cloud,Point3f force,float l,float time){
+@param MeshModel cloud  - Mesh of points
+@param Point3f   force  - Direction of the force
+@param float     l      - Lenght of the step
+@param float     time   - Time Step
+
+@return nothing
+*/
+void MoveCloudMeshForward(MeshModel *cloud,Point3f force,float l,float time){
     CMeshO::PerVertexAttributeHandle<Particle<CMeshO> > ph = Allocator<CMeshO>::GetPerVertexAttribute<Particle<CMeshO> >(cloud->cm,"ParticleInfo");
     CMeshO::VertexIterator vi;
     CMeshO::FacePointer current_face;
-    CMeshO::FacePointer new_face;
     float velocity;
     float mass;
     CMeshO::CoordType new_pos;
     CMeshO::CoordType current_pos;
     CMeshO::CoordType int_pos;
-
     for(vi=cloud->cm.vert.begin();vi!=cloud->cm.vert.end();++vi){
         float t=time;
-
         current_face=ph[vi].face;
         new_face=current_face   ;
         current_pos=vi->P();
-
         velocity=ph[vi].vel;
         mass=ph[vi].mass;
-
         new_pos=StepForward(vi->P(),velocity,mass,current_face,force,l,t);
-
         while(!IsOnFace(new_pos,current_face)){
-            bool tmp=ComputeIntersection(current_pos,new_pos,current_face,new_face,int_pos);
-            new_face->C()=Color4b::Yellow;
-            if(!tmp){
-                break;
-            }
+            CMeshO::FacePointer new_face;
+            ComputeIntersection(current_pos,new_pos,current_face,new_face,int_pos);
             new_pos=int_pos;
-
-           //Debug
-            current_face->C()=Color4b::Black;
             current_face=new_face;
-
             t=t/2;
             if(t>0.5){
             new_pos=StepForward(vi->P(),velocity,mass,current_face,force,l,t);
             }else{
                 current_face->C()=Color4b::Green;
                 if(!IsOnFace(new_pos,current_face)){
-                    CoordinateCorrection(new_pos,current_face);
                     Point3f bc;
-                    InterpolationParameters(*new_face,new_pos,bc);
-                    current_face->C()=Color4b::Red;
-
-                }
-
+                    InterpolationParameters(*current_face,new_pos,bc);
+                    }
             }
         }
-
         vi->P()=new_pos;
         ph[vi].face=current_face;
-
     }
-
     return true;
 };
 
diff --git a/src/fgt/filter_dirt/filter_dirt.cpp b/src/fgt/filter_dirt/filter_dirt.cpp
index fde3b9515..9b9f20d24 100644
--- a/src/fgt/filter_dirt/filter_dirt.cpp
+++ b/src/fgt/filter_dirt/filter_dirt.cpp
@@ -206,6 +206,7 @@ bool FilterDirt::applyFilter(QAction *filter, MeshDocument &md, RichParameterSet
 
         float default_time=1;
 
+        //Get Parameters
         Point3f dir=par.getPoint3f("force_dir");;
         float l =par.getAbsPerc("s_length");
         float v=par.getFloat("velocity");
@@ -217,6 +218,7 @@ bool FilterDirt::applyFilter(QAction *filter, MeshDocument &md, RichParameterSet
             associateParticles(base_mesh,cloud_mesh,m,v);
         }
 
+        //Move Cloud Mesh
         MoveCloudMeshForward(cloud_mesh,dir,l,1);
 
         break;