diff --git a/VolZmapCreation.cpp b/VolZmapCreation.cpp
index 07f6f16..1913825 100644
--- a/VolZmapCreation.cpp
+++ b/VolZmapCreation.cpp
@@ -505,6 +505,8 @@ VolZmap::CreateMapPart( int nMap, int nInfI, int nSupI, int nInfJ, int nSupJ, co
         nSupJ < 0  ||  nSupJ > m_nNy[nMap])
       return false ;
 
+   double dCosSmall = cos( EPS_ANG_SMALL * DEGTORAD) ;
+
    // Determinazione e ridimensionamento dei dexel interni alla trimesh
    for ( int i = nInfI ; i < nSupI ; ++ i) {
       for ( int j = nInfJ ; j < nSupJ ; ++ j) {
@@ -552,7 +554,7 @@ VolZmap::CreateMapPart( int nMap, int nInfI, int nSupI, int nInfJ, int nSupJ, co
                double dCos = IntersectionResults[k].dCosDN ;
 
                // entro nella superficie trimesh
-               if ( dCos < - EPS_SMALL) {
+               if ( dCos < - dCosSmall) {
 
                   ptIn = IntersectionResults[k].ptI ;
 
@@ -565,7 +567,7 @@ VolZmap::CreateMapPart( int nMap, int nInfI, int nSupI, int nInfJ, int nSupJ, co
                }
 
                // esco dalla superficie trimesh
-               else if ( dCos > EPS_SMALL  &&  bInside) {
+               else if ( dCos > dCosSmall &&  bInside) {
 
                   Point3d ptOut = IntersectionResults[k].ptI ;