diff --git a/Simulator.cpp b/Simulator.cpp
index dc8c7f8..63ced76 100644
--- a/Simulator.cpp
+++ b/Simulator.cpp
@@ -25,9 +25,11 @@
 #include "/EgtDev/Include/EGkCDeCylClosedSurfTm.h"
 #include "/EgtDev/Include/EGkCDeSpheClosedSurfTm.h"
 #include "/EgtDev/Include/EGkCDeConeFrustumClosedSurfTm.h"
+#include "/EgtDev/Include/EGkCDeClosedSurfTmClosedSurfTm.h"
 #include "/EgtDev/Include/EGkVolZmap.h"
 #include "/EgtDev/Include/EGkGeoVector3d.h"
 #include "/EgtDev/Include/EGkStringUtils3d.h"
+#include "/EgtDev/Include/EGkSurfLocal.h"
 #include "/EgtDev/Include/EXeCmdLogOff.h"
 #include "/EgtDev/Include/EXeConst.h"
 #include "/EgtDev/Include/EMkToolConst.h"
@@ -1353,44 +1355,62 @@ Simulator::ExecCollisionCheck( int& nCdInd, int& nObjInd, int nMoveType)
         // se utensile attivo su grezzo in lavoro e non è rapido, salto
          if ( bIsTool  &&  bIsRaw  &&  nMoveType != 0)
             continue ;
-        // se riferimento non trovato, si salta
-         const IGeoFrame3d* pGeoFrame = GetGeoFrame3d( m_pGeomDB->GetGeoObj( m_CollObj[j].nFrameId)) ;
-         if ( pGeoFrame == nullptr)
-            continue ;
         // esecuzione controlli di collisione
          bool bOk = true ;
-         Frame3d frObj = pGeoFrame->GetFrame() ;
-         if ( !  m_CollObj[j].vtMove.IsSmall())
-            frObj.Translate( m_CollObj[j].vtMove.x * frObj.VersX() +
-                             m_CollObj[j].vtMove.y * frObj.VersY() +
-                             m_CollObj[j].vtMove.z * frObj.VersZ()) ;
-         Frame3d frParent ; m_pGeomDB->GetGlobFrame( m_CollObj[j].nFrameId, frParent) ;
-         frObj.LocToLoc( frParent, frCd) ;
-         if ( m_CollObj[j].nType == MCH_SIM_COB_BOX) {
-            Vector3d vtDiag( m_CollObj[j].dPar1, m_CollObj[j].dPar2, m_CollObj[j].dPar3) ;
-            if ( pVZM != nullptr)
-               bOk = pVZM->AvoidBox( frObj, vtDiag, m_dSafeDist) ;
-            else
-               bOk = ! CDeBoxClosedSurfTm( frObj, vtDiag, m_dSafeDist, *pSTM) ;
+        // oggetti che richiedono frame associato (Box, Cylinder, Sphere, Cone)
+         if ( m_CollObj[j].nType != MCH_SIM_COB_POLY) {
+           // se riferimento non trovato, si salta
+            const IGeoFrame3d* pGeoFrame = GetGeoFrame3d( m_pGeomDB->GetGeoObj( m_CollObj[j].nFrameId)) ;
+            if ( pGeoFrame == nullptr)
+               continue ;
+            Frame3d frObj = pGeoFrame->GetFrame() ;
+            if ( !  m_CollObj[j].vtMove.IsSmall())
+               frObj.Translate( m_CollObj[j].vtMove.x * frObj.VersX() +
+                                m_CollObj[j].vtMove.y * frObj.VersY() +
+                                m_CollObj[j].vtMove.z * frObj.VersZ()) ;
+            Frame3d frParent ; m_pGeomDB->GetGlobFrame( m_CollObj[j].nFrameId, frParent) ;
+            frObj.LocToLoc( frParent, frCd) ;
+           // controlli di collisione
+            if ( m_CollObj[j].nType == MCH_SIM_COB_BOX) {
+               Vector3d vtDiag( m_CollObj[j].dPar1, m_CollObj[j].dPar2, m_CollObj[j].dPar3) ;
+               if ( pVZM != nullptr)
+                  bOk = pVZM->AvoidBox( frObj, vtDiag, m_dSafeDist) ;
+               else
+                  bOk = ! CDeBoxClosedSurfTm( frObj, vtDiag, m_dSafeDist, *pSTM) ;
+            }
+            else if ( m_CollObj[j].nType == MCH_SIM_COB_CYL) {
+               if ( pVZM != nullptr)
+                  bOk = pVZM->AvoidCylinder( frObj, m_CollObj[j].dPar1, m_CollObj[j].dPar2, m_dSafeDist) ;
+               else
+                  bOk = ! CDeCylClosedSurfTm( frObj, m_CollObj[j].dPar1, m_CollObj[j].dPar2, m_dSafeDist, *pSTM) ;
+            }
+            else if ( m_CollObj[j].nType == MCH_SIM_COB_SPHE) {
+               if ( pVZM != nullptr)
+                  bOk = pVZM->AvoidSphere( frObj.Orig(), m_CollObj[j].dPar1, m_dSafeDist) ;
+               else
+                  bOk = ! CDeSpheClosedSurfTm( frObj.Orig(), m_CollObj[j].dPar1, m_dSafeDist, *pSTM) ;
+            }
+            else if ( m_CollObj[j].nType == MCH_SIM_COB_CONE) {
+               if ( pVZM != nullptr)
+                  bOk = pVZM->AvoidConeFrustum( frObj, m_CollObj[j].dPar1, m_CollObj[j].dPar2, m_CollObj[j].dPar3, m_dSafeDist) ;
+               else
+                  bOk = ! CDeConeFrustumClosedSurfTm( frObj, m_CollObj[j].dPar1, m_CollObj[j].dPar2, m_CollObj[j].dPar3, m_dSafeDist, *pSTM) ;
+            }
          }
-         else if ( m_CollObj[j].nType == MCH_SIM_COB_CYL) {
-            if ( pVZM != nullptr)
-               bOk = pVZM->AvoidCylinder( frObj, m_CollObj[j].dPar1, m_CollObj[j].dPar2, m_dSafeDist) ;
+        // altrimenti poliedro
+         else {
+            SurfLocal SurfLoc( m_pGeomDB, m_CollObj[j].nFrameId, frCd) ;
+            const ISurfTriMesh* pStmLoc = GetSurfTriMesh( SurfLoc) ;
+            if ( pStmLoc != nullptr) {
+               if ( pVZM != nullptr)
+                  bOk = pVZM->AvoidSurfTm( *pStmLoc, m_dSafeDist) ;
+               else
+                  bOk = ! CDeClosedSurfTmClosedSurfTm( *pStmLoc, *pSTM, m_dSafeDist) ;
+            }
             else
-               bOk = ! CDeCylClosedSurfTm( frObj, m_CollObj[j].dPar1, m_CollObj[j].dPar2, m_dSafeDist, *pSTM) ;
-         }
-         else if ( m_CollObj[j].nType == MCH_SIM_COB_SPHE) {
-            if ( pVZM != nullptr)
-               bOk = pVZM->AvoidSphere( frObj.Orig(), m_CollObj[j].dPar1, m_dSafeDist) ;
-            else
-               bOk = ! CDeSpheClosedSurfTm( frObj.Orig(), m_CollObj[j].dPar1, m_dSafeDist, *pSTM) ;
-         }
-         else if ( m_CollObj[j].nType == MCH_SIM_COB_CONE) {
-            if ( pVZM != nullptr)
-               bOk = pVZM->AvoidConeFrustum( frObj, m_CollObj[j].dPar1, m_CollObj[j].dPar2, m_CollObj[j].dPar3, m_dSafeDist) ;
-            else
-               bOk = ! CDeConeFrustumClosedSurfTm( frObj, m_CollObj[j].dPar1, m_CollObj[j].dPar2, m_CollObj[j].dPar3, m_dSafeDist, *pSTM) ;
+               bOk = false ;
          }
+        // se trovata collisione
          if ( ! bOk) {
             nCdInd = i ;
             nObjInd = j ;
@@ -1973,6 +1993,10 @@ Simulator::AddCollisionObj( int nInd, bool bToolOn, int nFrameId, int nType, con
       if ( ( dPar1 < EPS_SMALL  &&  dPar2 < EPS_SMALL)  ||  dPar3 < EPS_SMALL)
          return false ;
       break ;
+   case MCH_SIM_COB_POLY :
+      if ( ! ExeSurfIsClosed( nFrameId))
+         return false ;
+      break ;
    default :
       return false ;
    }