Hi Body,
I use "BRepOffsetAPI_MakeOffset"
in OCC4.0 and OCC3.1 to create a offset wire and try to use different Join type(GeomAbs_Tangent,GeomAbs_Arc,GeomAbs_Tangent), but the results are the same, the Join type seems always keep GeomAbs_Arc. Who can tell me, it is OCC Bug or my way is wrong. my code as following,

Standard_Real m_Dis=5.;
GeomAbs_JoinType Join= GeomAbs_Intersection;
BRepOffsetAPI_MakeOffset aOffs(aWire,Join);


PG's picture


The documentation says this is the only type of joining implemented.

See below some of the text.
The default type is GeomAbs_Arc where the vertices
generate sections of a circle. At present, this is the only construction type implemented.

- Prasad

angel's picture

Hi Prasad,
Do you have any idea about offseting a wire or edge and the result still keeps the sharp?


PG's picture

Dear forum supervisor
Its more than 10 years, is there no support for
GeomAbs_Tangent and GeomAbs_Intersection yet

Forum supervisor's picture

Dear PG,

As you might know already, Open CASCADE Technology is an Open Source software published under GNU LGPL license and available to the whole community of its users absolutely free of charge.

Since Open CASCADE Technology is provided freely, it may only evolve thanks to:
a) debug and extensions made in the frames of the projects for our Customers (see our references at,
b) our projects in which we invest our own resources into OCCT development (see,
c) contributions made by the registered members of OCCT Open Source Community.

Therefore, if you have a need to improve or extend a particular functionality of our Open Source software, you might:
a) request our assistance in the frames of a support or a custom development project,
b) participate in our public projects aimed to the needed improvements or extensions,
c) contribute the results of your own development (as it is explained on our Collaborative development portal at

Whatever way you would chose we welcome your efforts to improve Open CASCADE Technology!

Best regards

Alain Bertrand's picture


I encountered this thread as I  was wondering about the exact meaning of GeomAbs_Tangent,GeomAbs_Arc,GeomAbs_Tangent.

I don't mind about the non implemented features but both in and there is no mention that only GeomAbs_Arc is implemented.

Does it mean that now others types are implemented or that there is something missing (or *I* am missing) in the documentation ?

On a related topic, I am looking for the exact effect of Intersection and SelfInter .

Thanks for your help.