Re: [Meshlab-devel] adding faces/vertices
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Re: [Meshlab-devel] adding faces/vertices
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From: skunkwerk <sku...@gm...> - 2008-08-19 04:05:34
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one more question: I've noticed when you're random-accessing vertices, you apparently need to do: m.vert[f.V(c)-&(*m.vert.begin())], where f is the face and V is the vertex. 1) I'm not quite sure while you need the m.vert.begin, as doesn't f.V() hold the absolute index of the vertex you want? 2) And if you do need it, wouldn't you also need to do a similar thing for random-accessing faces too? Because all I'm doing right now is: m.face[(*fit)], where fit is a face iterator. thanks, imran On Mon, Aug 18, 2008 at 8:12 PM, skunkwerk <sku...@gm...> wrote: > sorry Paolo, it turns out the problem was not with the allocator but my > code... it just took a lot of trial and error to pinpoint it as the segfault > wasn't giving me a line number to where the problem was. > > it's still segfaulting, however, when I try to access a vertex of a face > outside the vector's range (no surprise there); I think this is because the > new face's vertices are not properly initialized, as it ends up requesting a > vertex index in the billions... I've tried two different methods of > initializing vertices, but neither fixes the problem: > > vcg::tri::Allocator<CMeshO>::AddVertices(m,2);//2 new vertices, 1 old > vertex > > the first way: > m.face[m.face.size()-1].V(0) = &m.vert[m.vert.size()-2];//new vertex > m.face[m.face.size()-1].V(1) = &m.vert[m.vert.size()-1];//new vertex > m.face[m.face.size()-1].V(2) = &vertices[2];//old vertex: vertices[2] = > m.vert[f.V(2)-&(*m.vert.begin())]; > > the second way: > vi=m.vert.end();--vi;--vi;//vertices added to the back of the vector, > decrement because end() is past the last element, and second time because > added 2 vertices > ivp[0]=&*vi;(*vi).P()=intersections[0];++vi;//new vertex, intersections[0] > = Point3f(....) > ivp[1]=&*vi;(*vi).P()=intersections[1];//new vertex, intersections[1] = > Point3f(....) > ivp[2]=&vertices[2];//old vertex: vertices[2] = > m.vert[f.V(2)-&(*m.vert.begin())]; > fi = m.face.end();--fi;//faces added to back of vector, decrement because > end() is past the last element > (*fi).V(0)=ivp[0]; (*fi).V(1)=ivp[1]; (*fi).V(2)=ivp[2]; > > when I tried using CoordType(0.0f,-1.0f,1.0f) as used in the documentation > I got the error 'no matching function call to... (Point3<float>) (float, > float, float) even though I've declared CoordType and included allocate.h > > as the cause of the segfault is known in this case, I'm not attaching code > for people to replicate the issue - I'm just asking for the correct way of > doing this... > > appreciate the help, > imran > > > On Mon, Aug 18, 2008 at 12:52 AM, Paolo Cignoni < > pao...@is...> wrote: > >> Could you provide a 10~30 lines self contained command-line program that >> is AS SHORT AS POSSIBLE and that tries to duplicate your issue? >> Something in the style of the vcglib/apps/sample/trimesh_XXXX examples >> (just a .cpp and a .pro). >> >> >From just the two lines that you are repeatedly posting is impossible to >> understand what is your problem. >> If you post just these two lines nobody can help you. The context is >> necessary. You should know that... >> >> The program should be AS SHORT AS POSSIBLE that is should be impossible to >> remove any statement (any statement) without breaking its ability of >> duplicating the issue. >> If someone post a long bug-duplication program that could be made shorter >> anyone will think that the submitter is either lazy or that the submitter >> considers his time more precious that the others one. >> >> cheers >> p. >> >> >> >> >> >> skunkwerk wrote: >> >> i'm still struggling with how to add and delete faces... I no longer get >> the previous assertion error, but am now getting a segfault whenever I do: >> >> vcg::tri::Allocator<CMeshO>::Addvertices(m,2); >> vcg::tri::Allocator<CMeshO>::AddFaces(m,1); >> >> when I comment out those two lines, I don't get any crashes... >> what am I doing wrong? >> >> thanks, >> imran >> >> On Sat, Aug 16, 2008 at 11:07 AM, skunkwerk <sku...@gm...> wrote: >> >> i managed to track down the error once the compiler gave me the correct >> line... >> >> now i'm getting this assertion failure though: >> meshlab: ../../../../vcglib/vcg/complex/trimesh/allocate.h:513: static >> void >> vcg::tri::Allocator<AllocateMeshType>::CompactFaceVector(AllocateMeshType&) >> [with AllocateMeshType = CMeshO]: Assertion `(int)pos==m.fn' failed. >> >> this is how i'm adding/deleting faces: >> vcg::tri::Allocator<CMeshO>::AddFaces(m,1); >> vcg::tri::Allocator<CMeshO>::DeleteFace(m,fp);//delete old face, leave >> vertices >> vcg::tri::Allocator<CMeshO>::CompactFaceVector(m);//compact faces to >> remove those marked as deleted >> >> am i doing something wrong? >> >> thanks, >> imran >> >> On Thu, Aug 14, 2008 at 4:58 PM, skunkwerk <sku...@gm...> wrote: >> >> thanks Paolo, >> i had to write 200 lines of code to get the face splitting working - >> and it almost compiles, except for these 3 errors: >> >> colladaio.cpp:264: instantiated from here >> /usr/include/c++/4.3/bits/vector.tcc:293: error: array must be initialized >> with a brace-enclosed initializer >> /usr/include/c++/4.3/bits/vector.tcc:299: error: invalid array assignment >> /usr/include/c++/4.3/bits/stl_construct.h:88: error: request for member >> '~float [2]' in '* pointer', which is of non-class type 'float [2]' >> >> but i have no idea where in the code these errors are coming from, as >> those are all stl things... any suggestions on how to trace this? i'm using >> gcc >> >> OR if someone could tell me how to use the existing code in meshlab, >> that'd be great too >> >> imran >> >> On Thu, Aug 14, 2008 at 1:04 AM, Paolo Cignoni <pao...@is... >> > wrote: >> >> no, at the end. >> read this page (and referrred subpages too) >> >> http://vcg.sourceforge.net/index.php/Tutorial >> >> p, >> >> skunkwerk wrote: >> >> quick question: i was reading 'creating elements' on this wiki page: >> http://meshlab.sourceforge.net/wiki/index.php/Accessing_the_mesh >> >> when you call Allocator<CMeshO>::AddVertices or AddFaces, are >> vertices/faces added to the front of the vector? >> because the next line that describes specifying the vertex coordinates, >> etc. uses a pointer to the front of the vector >> >> thanks, >> imran >> >> >> ------------------------------------------------------------------------- >> 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 worldhttp://moblin-contest.org/redirect.php?banner_id=100&url=/ >> >> >> _______________________________________________ >> Meshlab-devel mailing lis...@li...https://lists.sourceforge.net/lists/listinfo/meshlab-devel >> >> >> >> -- >> Paolo Cignoni -- Senior Researcher >> Visual Computing Laboratory - ISTI - CNR http://vcg.isti.cnr.it/~cignoni <http://vcg.isti.cnr.it/%7Ecignoni> >> >> ISTI - CNR >> Via Moruzzi 1, >> 56124 Pisa >> ITALY >> >> >> ------------------------------------------------------------------------- >> 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=/ >> _______________________________________________ >> Meshlab-devel mailing list >> Mes...@li... >> https://lists.sourceforge.net/lists/listinfo/meshlab-devel >> >> >> >> >> ------------------------------ >> >> ------------------------------------------------------------------------- >> 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 worldhttp://moblin-contest.org/redirect.php?banner_id=100&url=/ >> >> ------------------------------ >> >> _______________________________________________ >> Meshlab-devel mailing lis...@li...https://lists.sourceforge.net/lists/listinfo/meshlab-devel >> >> >> >> -- >> Paolo Cignoni -- Senior Researcher >> Visual Computing Laboratory - ISTI - CNR http://vcg.isti.cnr.it/~cignoni <http://vcg.isti.cnr.it/%7Ecignoni> >> >> ISTI - CNR >> Via Moruzzi 1, >> 56124 Pisa >> ITALY >> >> >> ------------------------------------------------------------------------- >> 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=/ >> _______________________________________________ >> Meshlab-devel mailing list >> Mes...@li... >> https://lists.sourceforge.net/lists/listinfo/meshlab-devel >> >> > |