as I figured out my troubles result from errors in the shape. (Thanks for the tip that not closed edges have another color than yellow!) Now I was trying to heal the shape like that:
ShapeFix_Solid FixSolid; FixSolid.Init(FixSolid.SolidFromShell(TopoDS::Shell(aSewedShell)));
TopoDS_Shape result = FixSolid.Solid();
Handle(ShapeFix_Wireframe) sfwf = new ShapeFix_Wireframe;
sfwf->ModeDropSmallEdges() = Standard_True;
result = sfwf->Shape();
Obviously I am missing a point here. ASewedShell is a not correctly connected Shell consisting of Face that have been sewed using: BRepOffsetAPI_Sewing.
The shape healing user guide speaks about a controll flag CreateOpenShellMode. How can I set this to true? I could not find the flag in the OC source code. Can anyone give me some general information about the use of tolerance and precission?
Any hint could be helpful.