Set fixes nodes


I was wondering if it is possible to set a flag in the nodes that you don’t want to be remeshed or moved, this could be very interesting to fix the external nodes of a CFD volume, this way we can remesh just in the desired volume around an object, reducing the complexity of the remeshing.


Dear Loumalouomega,

Boundary nodes can be preserved using the RequiredVertices flag.
This flag is available:

  • using an medit input file (RequiredVertices keyword);
  • using the library API ( MMG3D_Set_requiredVertex(mesh, k), where k is the index of the vertex that you want to keep untouched).

Using the required flag ensure that we don’t modify the provided boundary nodes but Mmg is allowed to insert new nodes and to modify the boundary triangulation.

To preserve:

  • some boundary triangles (resp. edges), you can use the RequiredTriangles (resp. RequiredEdges) keywords;
  • the whole boundary triangulation, you can use the -nosurf ( MMG3D_Set_iparameter(mesh, sol, MMG3D_IPARAM_nosurf, 1)) option that forbid the boundary remeshing.

Best regards,



Thank you very much, that would be very useful