diff --git a/IntersLineSurfBez.cpp b/IntersLineSurfBez.cpp
index 09c7dab..7daf922 100644
--- a/IntersLineSurfBez.cpp
+++ b/IntersLineSurfBez.cpp
@@ -142,7 +142,7 @@ IntersLineSurfBz( const Point3d& ptL, const Vector3d& vtL, double dLen, const IS
          pSurfTm->GetTriangle( InfoTm.nT, nVert) ;
          double dU0, dV0 ;
          pSurfTm->GetVertexParam( nVert[0], dU0, dV0) ;
-         ptSP = ptSP + Point3d(dU0, dV0, 0) ;
+         ptSP = ptSP + Point3d( dU0, dV0, 0) ;
          if ( ! RefineIntersNewton( ptL,vtL, dLen, bFinite, pSurfBz, ptSP, ptIBz))
             return false ;
       }
diff --git a/SurfBezier.cpp b/SurfBezier.cpp
index 0df6b37..6a866b5 100644
--- a/SurfBezier.cpp
+++ b/SurfBezier.cpp
@@ -3021,9 +3021,12 @@ SurfBezier::UnprojectPointFromStm( int nT, const Point3d& ptI, Point3d& ptSP, in
    int nVert[3] ;
    pSurfTm->GetTriangle( nTriaIndex, nVert) ;
    PNTVECTOR vPtPa(3) ;
-   pSurfTm->GetVertexParam( nVert[0], vPtPa[0].x,vPtPa[0].y, false) ;
-   pSurfTm->GetVertexParam( nVert[1], vPtPa[1].x,vPtPa[1].y, false) ;
-   pSurfTm->GetVertexParam( nVert[2], vPtPa[2].x,vPtPa[2].y, false) ;
+   pSurfTm->GetVertexParam( nVert[0], vPtPa[0].x, vPtPa[0].y) ;
+   vPtPa[0] *= SBZ_TREG_COEFF ;
+   pSurfTm->GetVertexParam( nVert[1], vPtPa[1].x, vPtPa[1].y) ;
+   vPtPa[1] *= SBZ_TREG_COEFF ;
+   pSurfTm->GetVertexParam( nVert[2], vPtPa[2].x, vPtPa[2].y) ;
+   vPtPa[2] *= SBZ_TREG_COEFF ;
    PNTVECTOR vPT(3) ;
    pSurfTm->GetVertex( nVert[0], vPT[0]) ;
    pSurfTm->GetVertex( nVert[1], vPT[1]) ;
diff --git a/SurfTriMesh.cpp b/SurfTriMesh.cpp
index fde8ff7..789b8a5 100644
--- a/SurfTriMesh.cpp
+++ b/SurfTriMesh.cpp
@@ -512,21 +512,14 @@ SurfTriMesh::GetVertex( int nId, Point3d& ptP) const
 
 //----------------------------------------------------------------------------
 bool
-SurfTriMesh::GetVertexParam( int nId, double& dU, double& dV, bool bDownScaled) const
+SurfTriMesh::GetVertexParam( int nId, double& dU, double& dV) const
 {
   // verifico esistenza del vertice
    if ( nId < 0  ||  nId >= GetVertexSize()  ||  m_vVert[nId].nIdTria == SVT_DEL)
       return false ;
-  // recupero i dati
-   int SBZ_COEFF = 1024 ;
-   if( bDownScaled) {
-      dU = m_vVert[nId].dU / SBZ_COEFF ;
-      dV = m_vVert[nId].dV / SBZ_COEFF ;
-   }
-   else {
-      dU = m_vVert[nId].dU ;
-      dV = m_vVert[nId].dV ;
-   }
+  // recupero i dati (verso l'esterno sempre in 0..1..2..3..)
+   dU = m_vVert[nId].dU / PREC_SCALE_COEFF ;
+   dV = m_vVert[nId].dV / PREC_SCALE_COEFF ;
    return true ;
 }
 
diff --git a/SurfTriMesh.h b/SurfTriMesh.h
index 5990a77..12c886e 100644
--- a/SurfTriMesh.h
+++ b/SurfTriMesh.h
@@ -277,7 +277,7 @@ class SurfTriMesh : public ISurfTriMesh, public IGeoObjRW
       bool GetShowEdges( void) const override
               { return m_bShowEdges ; }
       bool GetVertex( int nId, Point3d& ptP) const override ;
-      bool GetVertexParam( int nId, double& dU, double& dV, bool bDownScaled = true) const override ;
+      bool GetVertexParam( int nId, double& dU, double& dV) const override ;
       int  GetFirstVertex( Point3d& ptP) const override ;
       int  GetNextVertex( int nId, Point3d& ptP) const override ;
       bool GetTriangle( int nId, int nIdVert[3]) const override ;
diff --git a/SurfTriMeshBooleans.cpp b/SurfTriMeshBooleans.cpp
index 3aed42c..bce4122 100644
--- a/SurfTriMeshBooleans.cpp
+++ b/SurfTriMeshBooleans.cpp
@@ -41,7 +41,7 @@
 using namespace std ;
 
 //----------------------------------------------------------------------------
-const double BOOLEAN_SCALE = 1024 ;
+const double BOOLEAN_SCALE = PREC_SCALE_COEFF ;
 
 //----------------------------------------------------------------------------
 bool
diff --git a/SurfTriMeshCuts.cpp b/SurfTriMeshCuts.cpp
index f6bcbec..5a106ca 100644
--- a/SurfTriMeshCuts.cpp
+++ b/SurfTriMeshCuts.cpp
@@ -26,7 +26,7 @@
 using namespace std ;
 
 //----------------------------------------------------------------------------
-const double CUT_SCALE = 1024 ;
+const double CUT_SCALE = PREC_SCALE_COEFF ;
 
 //----------------------------------------------------------------------------
 bool