- if ( aSewedShape.ShapeType() == TopAbs_FACE && aCaseRegions.Length() ==1 ) {
- // create shell from one face
- BRep_Builder aBuilder;
- aBuilder.MakeShell( aShell );
- aBuilder.Add( aShell, aSewedShape);
- } else {
- TopExp_Explorer anExpShells( aSewedShape, TopAbs_SHELL );
- Standard_Integer aNbOfShells = 0;
- for ( ; anExpShells.More(); anExpShells.Next() ) {
- aShell = TopoDS::Shell( anExpShells.Current() );
- aNbOfShells++;
+ if ( !aSewedShape.IsNull() )
+ {
+ if ( aSewedShape.ShapeType() == TopAbs_FACE && aCaseRegions.Length() ==1 ) {
+ // create shell from one face
+ BRep_Builder aBuilder;
+ aBuilder.MakeShell( aShell );
+ aBuilder.Add( aShell, aSewedShape);
+ } else {
+ TopExp_Explorer anExpShells( aSewedShape, TopAbs_SHELL );
+ Standard_Integer aNbOfShells = 0;
+ for ( ; anExpShells.More(); anExpShells.Next() ) {
+ aShell = TopoDS::Shell( anExpShells.Current() );
+ aNbOfShells++;
+ }
+
+ if ( aNbOfShells != 1 ) {
+ aShell.Nullify();
+ BRep_Builder aBuilder;
+ aBuilder.MakeShell( aShell );
+
+ TopExp_Explorer anExpFaces( aSewedShape, TopAbs_FACE );
+ for ( ; anExpFaces.More(); anExpFaces.Next() ) {
+ TopoDS_Face aFace = TopoDS::Face( anExpFaces.Current() );
+ if ( !aFace.IsNull() ) {
+ aBuilder.Add( aShell, aFace );
+ }
+ }
+ }