tutorial_07b.docu 1.97 KB
 Mike Kremer committed Jun 05, 2009 1 2 3 4 5 6 /** \page tutorial_07b Deleting geometry elements This small example shows how to remove faces and vertices from a mesh. We basically use the geometry created in \ref tutorial_01.  Mike Kremer committed Jan 22, 2010 7 If we want our mesh class to be able to remove vertices, faces or edges  Mike Kremer committed Jun 05, 2009 8 9 10 11 we have to extend the default traits for our mesh class. Vertices, faces and (half-)edges need the OpenMesh::Attributes::Status attribute which is used to hold the flag "deleted" if an element is deleted.  Matthias Möller committed Mar 11, 2015 12 13 14 15 Instead of defining the required attributes via traits on compile-time, it is possible to request attributes dynamically on run-time by requesting them. In this example, we want to delete faces, edges and vertices, therefore requesting the status attribute is required. \note You have to request attributes before you use them, if you don't enable them via traits.  Mike Kremer committed Jun 05, 2009 16 17  \dontinclude delete_geometry.cc  Matthias Möller committed Mar 11, 2015 18 19 \skipline // the request \until mesh.request_vertex_status();  Mike Kremer committed Jun 05, 2009 20 21  After having created the geometry of the cube one can delete faces and vertices  Mike Kremer committed Nov 27, 2009 22 by simply calling delete_vertices() (delete_faces() or delete_edges() respectively).  Mike Kremer committed Jun 05, 2009 23   Mike Kremer committed Jan 22, 2010 24 Note that there is actually no way to directly delete halfedges since they are automatically  Mike Kremer committed Jan 22, 2010 25 26 27 28 29 30 31 32 33 34 35 affected when the parent edge is marked as deleted! The status whether an element is marked as deleted can be requested by \code mesh.status(handle).deleted(); // true if element handle is marked as deleted // false otherwise \endcode where handle is either a vertex-, edge- or face-handle.  Mike Kremer committed Nov 27, 2009 36 In this example we delete all faces except one and the corresponding vertices.  Mike Kremer committed Jun 05, 2009 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 The code looks like this \dontinclude delete_geometry.cc \skipline // Delete face 0 \until mesh.delete_vertex(vhandle[3], false); Now the deleted faces and vertices are marked as "deleted" internally. Call garbage_collection() to definitely remove them from memory. \dontinclude delete_geometry.cc \skipline // Delete all \until mesh.garbage_collection(); The full source code of the example: \include delete_geometry.cc  Mike Kremer committed Nov 27, 2009 54 **/