- OpenMesh - lists.rwth-aachen.de

OpenMesh cmake config usage example ?
by Nicholas Yue 18 Nov '22

18 Nov '22

Hi, Is there a basic example to illustrate how one can link with OpenMesh static libraries via cmake I cannot find documentation regarding the config's target name for include and differentiation between static and shared ? I am using OpenMesh 9.0, I have built (both static and shared) on Ubuntu 18.04 Cheers -- Nicholas Yue https://www.linkedin.com/in/nicholasyue/

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triangle mesh refinement/subdivision in OpenMesh
by Xujun Zhao 22 Jun '22

22 Jun '22

Hi, I am new and recently started to play with OpenMesh. I would like to subdivide a triangle mesh based on midpoint criteria. It is required that the subdivided mesh has the same geometry as the original one. No geometry loss! I read a STL mesh and tried to use the uniform subdivider: ___________________________________________________________________ struct CustomTraits : public OpenMesh::DefaultTraitsDouble { }; typedef OpenMesh::TriMesh_ArrayKernelT<CustomTraits> OM_TriMesh; OM_TriMesh om_mesh; OpenMesh::IO::read_mesh( om_mesh, fname_in); int n_refine = 1; OpenMesh::Subdivider::Uniform::MidpointT<OM_TriMesh> divider; divider.attach(om_mesh); divider(n_refine); divider.detach(); OpenMesh::IO::write_mesh( om_mesh , fname_out); ____________________________________________________________________ Conceptually, I supposed it would uniformly divide one triangle into four triangles after connecting its edge midpoints. However, I found it was not true and the subdivided mesh is geometrically not exactly the same as the original one. In addition, for a simple mesh with only 1 triangle(stl format), I found that only the central triangle connected with midpoints is generated and triangles associated with the original vertices are lost. I looked at the source code, and found that it was caused by the "if (!_m.is_boundary(vh))" check. So it seems the boundary vertices are ignored. Then the geometry after subdivision became different from the original mesh. Is it true? Can anyone help and tell me how to do that? Thank you very much. Best, Xujun

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Building OpenMesh with CMake on Windows, missing includes (VCICommon)
by ugurguney＠gmail.com 28 May '22

28 May '22

Hi! I've cloned OpenMesh git repo to my local. created a build directory under it. there I called following CMake command for release mode without applications) ``` cmake .. -DCMAKE_BUILD_TYPE=Release -DBUILD_APPS=OFF ``` I'm getting following errors: ``` CMake Error at CMakeLists.txt:44 (include): include could not find requested file: VCICommon CMake Error at src/OpenMesh/Core/CMakeLists.txt:1 (include): include could not find requested file: VCICommon CMake Error at src/OpenMesh/Core/CMakeLists.txt:145 (vci_add_library): Unknown CMake command "vci_add_library". ``` Looks like it needs `vci_add_library` Cmake function that is defined in `VCICommon`. But I don't see VCICommon anywhere in the repo. From https://gitlab.vci.rwth-aachen.de:9000/search?search=VCICommon&nav_source=n… as you can see, VCICommon is only included in the repo, not defined anywhere. Can you please tell me what I am doing wrong. Thanks!

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Buiding deb package of OpenMesh
by Robert Niederreiter 11 Apr '22

11 Apr '22

Hi, i was going to try to build the deb packages for OpenMesh. However, i was immediately stopped in the first place, since there are rules contained building the apps which require QT4. In recent Ubuntu/Debian versions QT4 has been dropped. So i ask: * If building debian packages is something which happens in your CI (have not found anything in the code) * if the debian build rules may be a subject to change -> essentially skipping building the apps. Thanks, - Robert

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texture file support
by Philipp Auersperg-Castell 07 Mar '22

07 Mar '22

Hi Folks, for our project we needed support for texture files and have built it into Openmesh and also exposed it in openmesh-python. What we did in detail: OpenMesh: - added param 'texture_file' to the Options class, it specifies the path to the texture file - added param 'material_file_extension' to the Options class, it specifies the material file suffix, default is ".mat" as it was before, we needed it becuase Blender expects ".mtl" - removed default and copy constructor and destructor as well as assignment operator, because these are not necessary here, see https://en.cppreference.com/w/cpp/language/rule_of_three openmesh-python: - exposed the above features - exposed .is_locked and .set_locked - documented it in trimesh.rst I attatched the git diffs for OpenMesh and openmesh-python. Please let me know if it could be merged and if necessary what we could do better ;) regards Philipp Auersperg-Castell

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How to iterate over the vertices of a poly face and alter the humber
by camilotalero96＠hotmail.com 07 Mar '22

07 Mar '22

Pretty much the title. I am trying to clip a mesh against a plane, to that effect i need to check each face against the plane and either delete the face or modify it introducing new vertices. I am trying this to access the vertices: ```cpp MyMesh::FaceIter f_it, v_end(mesh.faces_end()); uint count = 0; for (f_it=mesh.faces_begin(); f_it!=v_end;) { auto old_it = f_it; MyMesh::FaceVertexCCWIter fv_iter = mesh.fv_ccwiter(old_it); std::vector< MyMesh::VertexIter > new_face_verts; for (; fv_iter.is_valid(); ++fv_iter) { mesh.point(fv_iter); } ++f_it; mesh.delete_face(*old_it, true); } mesh.garbage_collection(); ``` But this is apparently invalid. As no method in the mesh accepts that iterator.

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can't use read_mesh in python
by cherepashkin＠phystech.edu 29 Oct '21

29 Oct '21

I would like to use openmesh in python just to read a mesh from .obj from ShapeNet model. I did following: import openmesh as om from openmesh import * mesh = om.TriMesh() read_mesh(mesh, filename) And I have got error, "name 'read_mesh' is not defined". Was read_mesh replaced with something else?

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Fwd: OpenMesh Issue report
by Bruce Jones 12 Oct '21

12 Oct '21

Hi all, I am facing an issue dealing with complex faces in openmesh via the python interface. I have a mesh I am loading via trimesh (hard requirement at this time), and using that to build an openmesh mesh. This mesh (and others i work with) is degenerate in the sense that it has complex faces, and trying to ignore that problem leads to the python process crashing (either hanging or segfault/bus error depending on the mesh). If i proactively try to delete the complex faces immediately after they are created, I get a seg fault. I have attached a minimum working example complete with degenerate STL, I would appreciate any assistance debugging this and/or working around it! Cheers, Bruce

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Bug report
by Ramakrishnan Mukundan 14 Sep '21

14 Sep '21

Hi, I would like to report a bug in OBJReader of Open Mesh. I have written a program to read OBJ files and to render them using OpenGL. This program uses OpenMesh for loading files. When I load the attached file (CubeCol.obj), the program displays a gray coloured cube instead of a red cube (CubeCol.mtl defines the colour of the cube as red). All other object loaders and viewers (including Windows 3D viewer) displays the cube correctly with a red colour. I spent hours trying to identify the problem, and finally found out that if I remove the space character at the beginning of the last three lines in CubeCol.mtl, the cube gets displayed correctly. Apparently, OBJReader ignores lines in the mtl file where there is a space character in the first column. All other obj readers that I have used load the file correctly. Also, I have noticed that it is not sufficient to request face colours (mesh.request_face_colors()) before reading the mesh file to get the colour values from the mtl file. I also had to include IO::Options::FaceColor as the argument for the read_mesh() function to get face colours using mesh.color(faceHandle); I couldn't find any documentation giving the actual procedure for loading data from mtl files. Please let me know if I am using the correct method for loading obj files along with material properties. Thank you. Kind regards, Mukundan mukundan2013(a)gmail.com

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Cite OpenMesh in scientific publications
by btyukodi＠brandeis.edu 27 Aug '21

27 Aug '21

Dear All, I am about to submit a paper where I used a simulation which uses OpenMesh. First, let me thank the developers, contributors and everyone on this forum who helped me with my questions and problems on the way. Second, I was wondering whether there is one or more papers you would prefer me to cite. Thank you, Botond

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