diff --git a/EXE_GdbCreateCurve.cpp b/EXE_GdbCreateCurve.cpp
index e7b11f9..850345c 100644
--- a/EXE_GdbCreateCurve.cpp
+++ b/EXE_GdbCreateCurve.cpp
@@ -29,6 +29,7 @@
 #include "/EgtDev/Include/EGkLineTgCurvePerpCurve.h"
 #include "/EgtDev/Include/EGkCurveArc.h"
 #include "/EgtDev/Include/EGkCircleCenTgCurve.h"
+#include "/EgtDev/Include/EGkCircle2P.h"
 #include "/EgtDev/Include/EGkArcSpecial.h"
 #include "/EgtDev/Include/EGkArcPntDirTgCurve.h"
 #include "/EgtDev/Include/EGkArcCenTgCurvePnt.h"
@@ -764,6 +765,44 @@ ExeCreateCircleCPEx( int nParentId, const Point3d& ptCen,
    return nNewId ;
 }
 
+//-------------------------------------------------------------------------------
+int
+ExeCreateCircle2P( int nParentId, const Point3d& ptP1, const Point3d& ptP2, int nRefType)
+{
+   IGeomDB* pGeomDB = GetCurrGeomDB() ;
+   VERIFY_GEOMDB( pGeomDB, GDB_ID_NULL)
+   nParentId = AdjustId( nParentId) ;
+  // recupero il riferimento locale
+   Frame3d frLoc ;
+   if ( ! pGeomDB->GetGroupGlobFrame( nParentId, frLoc))
+      return GDB_ID_NULL ;
+  // porto in locale i punti e i versori
+   Point3d ptP1L = GetPointLocal( pGeomDB, ptP1, nRefType, frLoc) ;
+   Point3d ptP2L = GetPointLocal( pGeomDB, ptP2, nRefType, frLoc) ;
+   Vector3d vtNL = GetVectorLocal( pGeomDB, Z_AX, nRefType, frLoc) ;
+   Vector3d vtExtrL = GetVectorLocal( pGeomDB, Z_AX, nRefType, frLoc) ;
+  // calcolo la circonferenza
+   PtrOwner<ICurveArc> pCrvArc( GetCircle2P( ptP1L, ptP2L, vtNL)) ;
+   if ( IsNull( pCrvArc))
+      return GDB_ID_NULL ;
+  // assegno il versore estrusione
+   pCrvArc->SetExtrusion( vtExtrL) ;
+  // inserisco l'arco nel DB
+   int nId = pGeomDB->AddGeoObj( GDB_ID_NULL, nParentId, Release( pCrvArc)) ;
+   ExeSetModified() ;
+  // se richiesto, salvo il comando Lua equivalente
+   if ( IsCmdLog()) {
+      string sLua = "EgtCircle2P(" + IdToString( nParentId) + ",{" +
+                                     ToString( ptP1) + "}," +
+                                     ToString( ptP2) + "," +
+                                     RefTypeToString( nRefType) + ")" +
+                " -- Id=" + ToString( nId) ;
+      LOG_INFO( GetCmdLogger(), sLua.c_str()) ;
+   }
+  // restituisco l'identificativo della nuova entità
+   return nId ;
+}
+
 //-------------------------------------------------------------------------------
 int
 ExeCreateCircle3P( int nParentId, const Point3d& ptP1,
@@ -1293,18 +1332,34 @@ ExeCreateCurveFillet( int nParentId, int nCrv1, const Point3d& ptNear1,
    int nNewId = ( bOk ? pGeomDB->AddGeoObj( GDB_ID_NULL, nParentId, Release( pArc)) : GDB_ID_NULL) ;
   // se richiesto trim
    if ( nNewId != GDB_ID_NULL  &&  bTrim) {
-     // recupero e aggiusto la prima curva
+     // recupero prima curva
       ICurve* pCrv1 = GetCurve( pGeomDB->GetGeoObj( nCrv1)) ;
-      if ( dTrim1 > EPS_ZERO)
-         pCrv1->TrimStartAtParam( dTrim1) ;
-      else if ( dTrim1 < - EPS_ZERO)
-         pCrv1->TrimEndAtParam( abs( dTrim1)) ;
-     // recupero e aggiusto la seconda curva
+      double dLen1 = 0 ; pCrv1->GetLength( dLen1) ;
+      double dParS1 = 0, dParE1 = 1 ; pCrv1->GetDomain( dParS1, dParE1) ;
+     // se prima curva da eliminare
+      if ( abs( abs( dTrim1) - dParE1) * dLen1 < EPS_SMALL  ||  abs( abs( dTrim1) - dParS1) * dLen1 < EPS_SMALL)
+         pGeomDB->Erase( nCrv1) ;
+     // altrimenti da trimmare
+      else {
+         if ( dTrim1 > EPS_ZERO)
+            pCrv1->TrimStartAtParam( dTrim1) ;
+         else if ( dTrim1 < - EPS_ZERO)
+            pCrv1->TrimEndAtParam( abs( dTrim1)) ;
+      }
+     // recupero seconda curva
       ICurve* pCrv2 = GetCurve( pGeomDB->GetGeoObj( nCrv2)) ;
-      if ( dTrim2 > EPS_ZERO)
-         pCrv2->TrimStartAtParam( dTrim2) ;
-      else if ( dTrim2 < - EPS_ZERO)
-         pCrv2->TrimEndAtParam( abs( dTrim2)) ;
+      double dLen2 = 0 ; pCrv2->GetLength( dLen2) ;
+      double dParS2 = 0, dParE2 = 1 ; pCrv2->GetDomain( dParS2, dParE2) ;
+     // se seconda curva da eliminare
+      if ( abs( abs( dTrim2) - dParE2) * dLen2 < EPS_SMALL  ||  abs( abs( dTrim2) - dParS2) * dLen2 < EPS_SMALL)
+         pGeomDB->Erase( nCrv2) ;
+     // altrimenti da trimmare
+      else {
+         if ( dTrim2 > EPS_ZERO)
+            pCrv2->TrimStartAtParam( dTrim2) ;
+         else if ( dTrim2 < - EPS_ZERO)
+            pCrv2->TrimEndAtParam( abs( dTrim2)) ;
+      }
    }
    ExeSetModified() ;
   // se richiesto, salvo il comando Lua equivalente
diff --git a/EXE_GdbModifyCurve.cpp b/EXE_GdbModifyCurve.cpp
index c2081d7..a7669cb 100644
--- a/EXE_GdbModifyCurve.cpp
+++ b/EXE_GdbModifyCurve.cpp
@@ -1325,7 +1325,7 @@ ExeModifyCircle3P( int nId, const Point3d& ptP1, const Point3d& ptP2, const Poin
   // creo l'arco
    PtrOwner<ICurveArc> pCrvArc( CreateCurveArc()) ;
    if ( IsNull( pCrvArc))
-      return GDB_ID_NULL ;
+      return false ;
   // recupero il riferimento locale
    Frame3d frLoc ;
    if ( ! pGeomDB->GetGlobFrame( nId, frLoc))
@@ -1348,24 +1348,65 @@ ExeModifyCircle3P( int nId, const Point3d& ptP1, const Point3d& ptP2, const Poin
 }
 
 //-------------------------------------------------------------------------------
-bool
-ExeModifyArcRadius( int nId, double dRad)
+static bool
+MyModifyArcRadius( IGeomDB* pGeomDB, int nId, double dRad)
 {
-   IGeomDB* pGeomDB = GetCurrGeomDB() ;
-   VERIFY_GEOMDB( pGeomDB, false)
   // recupero l'arco e i suoi dati
    ICurveArc* pArc = GetCurveArc( pGeomDB->GetGeoObj( nId)) ;
    if ( pArc == nullptr)
       return false ;
-   double dOldRad = pArc->GetRadius() ;
   // imposto il nuovo raggio
-   if ( pArc->ChangeRadius( dRad))
-      return true ;
-  // in caso di errore, ripristino i vecchi dati
-   else {
-      pArc->ChangeRadius( dOldRad) ;
+   return pArc->ChangeRadius( dRad) ;
+}
+
+//-------------------------------------------------------------------------------
+static bool
+MyModifyArcRadiusEx( IGeomDB* pGeomDB, int nId, double dRad)
+{
+  // recupero l'arco e i suoi dati
+   ICurveArc* pArc = GetCurveArc( pGeomDB->GetGeoObj( nId)) ;
+   if ( pArc == nullptr)
       return false ;
+  // recupero gli estremi dell'arco e la loro distanza nel piano dell'arco
+   Point3d ptStart, ptEnd ;
+   if ( ! pArc->GetStartPoint( ptStart)  ||  ! pArc->GetEndPoint( ptEnd))
+      return false ;
+   double dPlaneDist = OrthoCompo( ( ptEnd - ptStart), pArc->GetNormVersor()).Len() ;
+  // se angolo al centro maggiore o uguale ad un giro o estremi coincidenti, conservo il centro
+   if ( abs( pArc->GetAngCenter()) >= ANG_FULL - EPS_ANG_ZERO  ||  dPlaneDist < 2 * EPS_SMALL)
+      return MyModifyArcRadius( pGeomDB, nId, dRad) ;
+  // mantengo i punti estremi (pertanto il nuovo raggio non può essere inferiore a metà della loro distanza nel piano)
+   if ( dRad < dPlaneDist / 2 - EPS_ZERO)
+      return false ;
+  // creo arco con gli stessi estremi, con identica normale e con nuovo raggio
+   PtrOwner<ICurveArc> pCrvArc( CreateCurveArc()) ;
+   if ( IsNull( pCrvArc)  ||
+        ! pCrvArc->Set2PNRS( ptStart, ptEnd, pArc->GetNormVersor(), dRad, pArc->GetAngCenter() > 0))
+      return false ;
+  // lo sostituisco all'originale
+   return pGeomDB->ReplaceGeoObj( nId, Release( pCrvArc)) ;
+}
+
+//-------------------------------------------------------------------------------
+bool
+ExeModifyArcRadius( int nId, double dRad, bool bKeepCenter)
+{
+   IGeomDB* pGeomDB = GetCurrGeomDB() ;
+   VERIFY_GEOMDB( pGeomDB, false)
+
+   bool bOk = ( bKeepCenter ? MyModifyArcRadius( pGeomDB, nId, dRad) : MyModifyArcRadiusEx( pGeomDB, nId, dRad)) ;
+   if ( bOk)
+      ExeSetModified() ;
+
+  // se richiesto, salvo il comando Lua equivalente
+   if ( IsCmdLog()) {
+      string sLua = "EgtModifyArcRadius(" + IdToString( nId) + "," +
+                                            ToString( dRad) + ")" +
+                     " -- Ok=" + ToString( bOk) ;
+      LOG_INFO( GetCmdLogger(), sLua.c_str()) ;
    }
+
+   return bOk ;
 }
 
 //-------------------------------------------------------------------------------
diff --git a/EgtExecutor.rc b/EgtExecutor.rc
index 832453c..f3a1091 100644
Binary files a/EgtExecutor.rc and b/EgtExecutor.rc differ
diff --git a/LUA_GdbCreateCurve.cpp b/LUA_GdbCreateCurve.cpp
index 9b24e03..1550fdd 100644
--- a/LUA_GdbCreateCurve.cpp
+++ b/LUA_GdbCreateCurve.cpp
@@ -235,6 +235,30 @@ LuaCreateCircleCPEx( lua_State* L)
    return 1 ;
 }
 
+//-------------------------------------------------------------------------------
+static int
+LuaCreateCircle2P( lua_State* L)
+{
+  // 3 o 4 parametri : ParentId, PtP1, PtP2 [, nRefType]
+   int nParentId ;
+   LuaCheckParam( L, 1, nParentId)
+   Point3d ptP1 ;
+   LuaCheckParam( L, 2, ptP1)
+   Point3d ptP2 ;
+   LuaCheckParam( L, 3, ptP2)
+   int nRefType = RTY_DEFAULT ;
+   LuaGetParam( L, 4, nRefType) ;
+   LuaClearStack( L) ;
+  // creo l'arco
+   int nId = ExeCreateCircle2P( nParentId, ptP1, ptP2, nRefType) ;
+  // restituisco il risultato
+   if ( nId != GDB_ID_NULL)
+      LuaSetParam( L, nId) ;
+   else
+      LuaSetParam( L) ;
+   return 1 ;
+}
+
 //-------------------------------------------------------------------------------
 static int
 LuaCreateCircle3P( lua_State* L)
@@ -1026,6 +1050,7 @@ LuaInstallGdbCreateCurve( LuaMgr& luaMgr)
    bOk = bOk && luaMgr.RegisterFunction( "EgtCircle", LuaCreateCircle) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtCircleCP", LuaCreateCircleCP) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtCircleCPEx", LuaCreateCircleCPEx) ;
+   bOk = bOk && luaMgr.RegisterFunction( "EgtCircle2P", LuaCreateCircle2P) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtCircle3P", LuaCreateCircle3P) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtArc", LuaCreateArc) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtArcCPA", LuaCreateArcCPA) ;
diff --git a/LUA_GdbModifyCurve.cpp b/LUA_GdbModifyCurve.cpp
index 98692fa..36778d4 100644
--- a/LUA_GdbModifyCurve.cpp
+++ b/LUA_GdbModifyCurve.cpp
@@ -516,14 +516,16 @@ LuaSplitCurveAtSelfInters( lua_State* L)
 static int
 LuaModifyArcRadius( lua_State* L)
 {
-  // 2 parametri : Id, dNewRad
+  // 2 o 3 parametri : Id, dNewRad [, bKeepCenter]
    int nId ;
    LuaCheckParam( L, 1, nId)
    double dNewRad ;
    LuaCheckParam( L, 2, dNewRad)
+   bool bKeepCenter = true ;
+   LuaGetParam( L, 3, bKeepCenter) ;
    LuaClearStack( L) ;
   // modifica del raggio
-   bool bOk = ExeModifyArcRadius( nId, dNewRad) ;
+   bool bOk = ExeModifyArcRadius( nId, dNewRad, bKeepCenter) ;
    LuaSetParam( L, bOk) ;
    return 1 ;
 }