On Wed, Feb 5, 2025 at 1:24 PM neil liu <liufi...@gmail.com> wrote:
> The corners can be set with MMG's own API function, LIBMMG3D_EXPORT int > MMG3D_Set_corner(MMG5_pMesh mesh, MMG5_int k); > This definitely sets a corner attribute on a vertex. > The edges can be set with MMG's own API function, LIBMMG3D_EXPORT int > MMG3D_Set_edges(MMG5_pMesh mesh, MMG5_int *edges, MMG5_int* refs); > This seems to define all the edges in the mesh. Are you saying that MMG only uses these edge definitions for open boundaries? > MMG doesn't have a very detailed documentation. The above API subroutines > can be found, > mmg/src/mmg3d/libmmg3d.h at master · MmgTools/mmg · GitHub > <https://urldefense.us/v3/__https://github.com/MmgTools/mmg/blob/master/src/mmg3d/libmmg3d.h__;!!G_uCfscf7eWS!bKdWOtCvA_Azjc29v2WxofGzpDjbNC-541kCXKvj0mo0SQ3dcS8irHwWYb3ckQSWb9JR7g5WkUqnonymjfwv$ > > > Thanks, Matt > Thanks, > > Xiaodong > > On Wed, Feb 5, 2025 at 1:16 PM Matthew Knepley <knep...@gmail.com> wrote: > >> On Wed, Feb 5, 2025 at 1:06 PM neil liu <liufi...@gmail.com> wrote: >> >>> Hi, Matt, >>> >>> It is not enough to only turn on -the open boundary. >>> For the above example, the 4 physical corner vertices (0D) for this >>> internal quadrilateral surface have to be set, otherwise the shape can not >>> be kept. >>> In addition, for my present case, the boundary edges (1D) consisting of >>> this quadrilateral surface need to be tagged. >>> The present bdLabel seems to only work for 2D shapes for 3D cases. >>> Please correct me if I am wrong. >>> >> >> Are you saying that this is the interface published by MMG? Can you point >> me toward the piece of MMG documentation? I just want to understand the >> interface requirements before we make any changes to PETSc. >> >> Thanks, >> >> Matt >> >> >>> >>> Thanks, >>> >>> Xiaodong >>> >>> On Wed, Feb 5, 2025 at 12:05 PM Matthew Knepley <knep...@gmail.com> >>> wrote: >>> >>>> This is a really poor name. The boundary is not open in any sense. It >>>> should be called an internal boundary, and what they call internal >>>> boundaries should be called interdomain boundaries, but it seems too late >>>> to fix this. >>>> >>>> Turning on open boundaries is just a flag, so that is easy, and one can >>>> see the usefulness of this mode. >>>> >>>> My understanding from the documentation link below is that MMG does not >>>> change anything about parts of the mesh marked >>>> as internal boundaries, so we can read them right back out from the >>>> boundary label. Why would we need a new label for this? >>>> >>>> Thanks, >>>> >>>> Matt >>>> >>>> On Wed, Feb 5, 2025 at 11:22 AM Pierre Jolivet <pie...@joliv.et> wrote: >>>> >>>>> See also: >>>>> https://urldefense.us/v3/__https://www.mmgtools.org/mmg-remesher-try-mmg/mmg-remesher-tutorials/mmg-remesher-mmg3d/open-boundary-remeshing__;!!G_uCfscf7eWS!bKdWOtCvA_Azjc29v2WxofGzpDjbNC-541kCXKvj0mo0SQ3dcS8irHwWYb3ckQSWb9JR7g5WkUqnorKeyTJt$ >>>>> >>>>> . >>>>> >>>>> Thanks, >>>>> Pierre >>>>> >>>>> On 5 Feb 2025, at 4:39 PM, neil liu <liufi...@gmail.com> wrote: >>>>> >>>>> It seems the figures were broken. Please see the following attached. >>>>> >>>>> On Wed, Feb 5, 2025 at 10:36 AM neil liu <liufi...@gmail.com> wrote: >>>>> >>>>>> Hi, Mark, >>>>>> >>>>>> For example, in the left figure, the yellow rectangular face needs to >>>>>> be preserved during mesh refinement. However, without specifying its four >>>>>> corner points, the rectangle cannot be maintained, as shown in the right >>>>>> figure. Additionally, the four edges of this face must be recorded and >>>>>> retrieved for post-processing. >>>>>> >>>>>> This yellow face is an *open boundary*, meaning it is not an >>>>>> interface between different materials. To ensure its preservation during >>>>>> mesh refinement, MMG must be run in *opnbdy* (open boundary) mode. >>>>>> >>>>>> Thanks a lot, >>>>>> >>>>>> Xiaodong >>>>>> [image: image.png] [image: image.png] >>>>>> >>>>>> >>>>>> On Wed, Feb 5, 2025 at 10:05 AM Matthew Knepley <knep...@gmail.com> >>>>>> wrote: >>>>>> >>>>>>> On Wed, Feb 5, 2025 at 9:52 AM neil liu <liufi...@gmail.com> wrote: >>>>>>> >>>>>>>> Dear developers, >>>>>>>> >>>>>>>> I am currently working with MMG in the context of PETSc and have >>>>>>>> identified a need to modify the existing MMG interface, >>>>>>>> DMAdaptMetric_Mmg_Plex(), for our use case. Given these >>>>>>>> requirements, I would like to explore the feasibility of contributing >>>>>>>> to >>>>>>>> PETSc to enhance this interface, which has been verified and validated >>>>>>>> in >>>>>>>> our research code. >>>>>>>> *Proposed Modifications:* >>>>>>>> >>>>>>>> 1. >>>>>>>> >>>>>>>> *Additional Labels for Physical Entities:* >>>>>>>> - In addition to the existing bdLabel and rgLabel, our case >>>>>>>> requires two additional labels to represent physical vertices >>>>>>>> and edges >>>>>>>> within the computational domain (3D). >>>>>>>> >>>>>>>> I am open to this. Can you be more specific about what it means? >>>>>>> >>>>>>>> >>>>>>>> 1. >>>>>>>> - One approach is to introduce two new parameters in the >>>>>>>> subroutine’s input list. However, this may require modifications >>>>>>>> across >>>>>>>> related components, such as Pragmatic. >>>>>>>> >>>>>>>> This is not a problem. I can modify those. >>>>>>> >>>>>>>> >>>>>>>> 1. >>>>>>>> >>>>>>>> *Support for Open Boundaries:* >>>>>>>> - The current interface does not support open boundaries, a >>>>>>>> feature available in MMG. >>>>>>>> - As a result, several MMG benchmark cases involving open >>>>>>>> boundary remeshing cannot be executed within PETSc. >>>>>>>> >>>>>>>> Can you explain what this means? What is an open boundary exactly? >>>>>>> >>>>>>> >>>>>>>> Would this be a viable contribution to PETSc? If so, I would >>>>>>>> appreciate any guidance on the best approach to implementing these >>>>>>>> changes >>>>>>>> while maintaining compatibility with existing features. >>>>>>>> >>>>>>> Yes. Please make a fork of the petsc repo, make a branch with the >>>>>>> proposed changes, make an MR for that branch, and add me to your fork >>>>>>> (I am >>>>>>> knepley on GitLab). I can help you get it going. >>>>>>> >>>>>>> Thanks, >>>>>>> >>>>>>> Matt >>>>>>> >>>>>>> >>>>>>>> Looking forward to your thoughts. >>>>>>>> >>>>>>>> Best regards, >>>>>>>> >>>>>>>> Thanks, >>>>>>>> Xiaodong >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> -- >>>>>>> What most experimenters take for granted before they begin their >>>>>>> experiments is infinitely more interesting than any results to which >>>>>>> their >>>>>>> experiments lead. >>>>>>> -- Norbert Wiener >>>>>>> >>>>>>> https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bKdWOtCvA_Azjc29v2WxofGzpDjbNC-541kCXKvj0mo0SQ3dcS8irHwWYb3ckQSWb9JR7g5WkUqnojvlDqER$ >>>>>>> >>>>>>> <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!anvbtQDqn57whvgg2qc1Dix0Izm9kxNlvUkeyYkcfknnt6VmqbCE0mlGSj6O1DLJx6qR7-7UsHv48zbaqVDECw$> >>>>>>> >>>>>> <The right figure.png><The left figure.png> >>>>> >>>>> >>>>> >>>> >>>> -- >>>> What most experimenters take for granted before they begin their >>>> experiments is infinitely more interesting than any results to which their >>>> experiments lead. >>>> -- Norbert Wiener >>>> >>>> https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bKdWOtCvA_Azjc29v2WxofGzpDjbNC-541kCXKvj0mo0SQ3dcS8irHwWYb3ckQSWb9JR7g5WkUqnojvlDqER$ >>>> >>>> <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bKdWOtCvA_Azjc29v2WxofGzpDjbNC-541kCXKvj0mo0SQ3dcS8irHwWYb3ckQSWb9JR7g5WkUqnorzjJhf8$ >>>> > >>>> >>> >> >> -- >> What most experimenters take for granted before they begin their >> experiments is infinitely more interesting than any results to which their >> experiments lead. >> -- Norbert Wiener >> >> https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bKdWOtCvA_Azjc29v2WxofGzpDjbNC-541kCXKvj0mo0SQ3dcS8irHwWYb3ckQSWb9JR7g5WkUqnojvlDqER$ >> >> <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bKdWOtCvA_Azjc29v2WxofGzpDjbNC-541kCXKvj0mo0SQ3dcS8irHwWYb3ckQSWb9JR7g5WkUqnorzjJhf8$ >> > >> > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bKdWOtCvA_Azjc29v2WxofGzpDjbNC-541kCXKvj0mo0SQ3dcS8irHwWYb3ckQSWb9JR7g5WkUqnojvlDqER$ <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bKdWOtCvA_Azjc29v2WxofGzpDjbNC-541kCXKvj0mo0SQ3dcS8irHwWYb3ckQSWb9JR7g5WkUqnorzjJhf8$ >
