Hi again, Okay, the basic functionality for subdivision surface FEM should be implemented now, but I have a question regarding proper integration into libmesh: These elements need some additional variables to store subdivision surface properties. For example, a vector of the 1-ring of neighbors is needed. Some of these properties also need to be accessible from the application code, for example to create a local coordinate system from the surface tangents.
Now, which class should I derive the elements from? Somehow, I feel that FE<2,SUBDIV> does not make too much sense since it has no containers for the extra variables. On the other hand, all other libmesh machinery relies on fe.h only and it's probably not the idea to change that. Thanks in advance, Norbert Norbert Stoop wrote: > Hi, > > Recently, subdivision surfaces were suggested as an alternative way to > construct C1 (and higher) conforming surface meshes for finite element > simulations. Now, I'm wondering how hard it would be to implement such > elements in libmesh: > Assuming triangular elements, the subdivision surface approach results > in 12 b-spline shape functions per element. The isoparametric map to > real space is a combination of them multiplied with the real space > position of the triangle's nodes *and* its next neighbor nodes (the > 1-ring of triangles around the element). > Looking at existing libmesh elements (lagrange, clough), I see that only > the ::shape, ::shape_deriv and ::shape_second_deriv are typically > overwritten, and the mapping to real space is done by libmesh > (fe_base.C, I think). > As pointed out above, the subdivision elements have a special mapping to > real space, which needs to take the neighboring nodes' position into > account. Is there a way to accomplish this in the current code or would > it be possible to extend it in that way? > > Thanks in advance, > Norbert > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's challenge > Build the coolest Linux based applications with Moblin SDK & win great prizes > Grand prize is a trip for two to an Open Source event anywhere in the world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > Libmesh-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/libmesh-users > ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
