try {
if ( !S1.IsNull() ) {
/* erase any previous */
-#if OCC_VERSION_LARGE <= 0x06060000
- ic->Erase( mySimulationShape1, Standard_True, Standard_False );
-#else
ic->Erase( mySimulationShape1, Standard_True );
-#endif
ic->ClearPrs( mySimulationShape1 );
mySimulationShape1 = new AIS_Shape( TopoDS_Shape() );