[Gmsh] "Tag # already exists" with OpenCASCADE engine

[Wang Bin]

Dear Dr. Geuzaine,

Thanks for you rapid reply.

Based on your suggestion, now I'm working on normal vector issue in a
simplified problem.

Now I found a potential bug in Gmsh. When I use build-in geometry engine,
the normal vector are all in the same direction.
But when I switch to OpenCASCADE engine (adding SetFactory("OpenCASCADE")),
the normal vector shows different. All of other info in geo file is exactly
the same.

How do I resolve this issue?
[image: image.png]  [image: image.png]

Please check attachment geo file to see the details.

Thanks,
Bin

Christophe Geuzaine <cgeuzaine at uliege.be> 于2018年10月16日周二 下午4:39写道：

>
>
> On 16 Oct 2018, at 17:03, Wang Bin <binwang.0213 at gmail.com> wrote:
>
> Dear Developers,
>
> Thanks for the nice mesh generator.  Now I'm trying to
> use BooleanFragments in OpenCASCADE engine to mesh some "compsolid" model
> (picture) with conforming mesh on the common interface (see attachment geo
> file).
>
> <compsolid.PNG>
> But the OpenCASCADE engine will add new Points, Lines or Surfaces during
> the boolean operation. Thus, Gmsh keeps give me a error "Point/Line/Surface
> # already exists".
>
> So, is there any method/tricks to avoid this issue? Such as reserve some
> tag id for the New geometry objects. Why Gmsh not using "newreg" internally
> to append new geometry?
>
>
> Your surfaces are not correctly oriented, which leads to the creation of
> new entities when you create "surface loops". The duplicates are reported
> when you force the creation of new points after these extra entities have
> been created.
>
> Christophe
>
>
>
>
>
> Thanks for your help!
> --
> Bin Wang
> PhD Student
> Craft & Hawkins Department of Petroleum Engineering
> Louisiana State University
> 2245 Patrick F Taylor Hall, Baton Rouge, LA  70803
> <composolid_new.geo>_______________________________________________
> gmsh mailing list
> gmsh at onelab.info
> http://onelab.info/mailman/listinfo/gmsh
>
>
> —
> Prof. Christophe Geuzaine
> University of Liege, Electrical Engineering and Computer Science
> http://www.montefiore.ulg.ac.be/~geuzaine
>
> Free software: http://gmsh.info | http://getdp.info | http://onelab.info
>
>

-- 
Bin Wang
PhD Student
Craft & Hawkins Department of Petroleum Engineering
Louisiana State University
2245 Patrick F Taylor Hall, Baton Rouge, LA  70803
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