Hi, I didn't change inverse_map, but the contains_point function. Sorry for the confusion I created. Hannes On Friday 25 March 2011 10.14:38 Kirk, Benjamin (JSC-EG311) wrote: > I'd propose if any changes are made to inverse_map() to check that the > mapped point agrees that it be turned on only through an optional argument > or something like that. I'm pretty sure there are places that rely on > finding this normal projection to get the *closest* point, even if it is > not an exact match. I know I've used that in applications, at least... > > -Ben > > > > ________________________________________ > From: Roy Stogner [[email protected]] > Sent: Friday, March 25, 2011 12:05 AM > To: [email protected] > Cc: [email protected] > Subject: Re: [Libmesh-users] Problem with contains_point in face element in > 3D > > On Fri, 25 Mar 2011, [email protected] wrote: > > I have a 2D mesh in 3 spacial dimensions and I'd like to get the > > element, which contains a point. The point_locator uses > > Elem::contains_point which uses FEInterface::inverse_map and then > > checks, if the reference point is in the reference element. For 3D > > points the inverse map is not defined in the whole space, which causes > > problems, when mapping non coplanar points falsely to the reference > > element. > > Hmm... yes, inverse_map() is solving the normal equations, and so > ought to be converging to the inverse of the projection of the point > into the plane/line of the element... which is fine on interior meshes > or on boundary meshes generated from "flat enough" boundary subsets > but which would give false positives for many boundary meshes. > > > I then changed the function a bit by mapping the reference > > point back again in physical space and checked the distance there for > > < tol*hmin(). However now it looks like I've got other problems > > probably caused by this hack. > > That sounds like the right fix, but inverse_map is used in a lot of > places and it would indeed be easy to break something else by missing > a corner case... like we seem to have done in the first place. > > Are your other problems replicable on any of the examples or on > anything you can send us in a short code? > > > Am I doing something wrong, is there a common pitfall with boundary > > meshes, or does anybody know, how to locate an element containing the > > point on boundary meshes. > > You're doing everything right, and found a bug that needs fixing; it's > just not a common pitfall because it's not a common usage type, I > suppose. > --- > Roy > > --------------------------------------------------------------------------- >--- Enable your software for Intel(R) Active Management Technology to meet > the growing manageability and security demands of your customers. > Businesses are taking advantage of Intel(R) vPro (TM) technology - will > your software be a part of the solution? Download the Intel(R) > Manageability Checker today! http://p.sf.net/sfu/intel-dev2devmar > _______________________________________________ > Libmesh-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/libmesh-users > > --------------------------------------------------------------------------- >--- Enable your software for Intel(R) Active Management Technology to meet > the growing manageability and security demands of your customers. > Businesses are taking advantage of Intel(R) vPro (TM) technology - will > your software be a part of the solution? Download the Intel(R) > Manageability Checker today! http://p.sf.net/sfu/intel-dev2devmar > _______________________________________________ > Libmesh-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/libmesh-users
-- ************************************************* Johannes Huber Mathematisches Institut Universität Basel Rheinsprung 21 CH-4051 Basel Switzerland Phone: +41 61 267 39 93 http://www.math.unibas.ch/~huber/ ************************************************* ------------------------------------------------------------------------------ Enable your software for Intel(R) Active Management Technology to meet the growing manageability and security demands of your customers. Businesses are taking advantage of Intel(R) vPro (TM) technology - will your software be a part of the solution? Download the Intel(R) Manageability Checker today! http://p.sf.net/sfu/intel-dev2devmar _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
