surface of a convex 3d data
in [Matlab]
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From: adel on 26 Mar 2010 10:56 Hello Is there a way to create a surface for my 3d convex data? (I need the 3d grid) input: http://s3.postimage.org/l6siJ-645ca509f0b6c348e94789e4519653ac.jpg output (looks like this): http://www.postimage.org/image.php?v=Tswg8eS
From: Máday Péter on 26 Mar 2010 13:14 Hello Unfortunately your first link does not seem to work (at least for me), but based on your description it seems to me that you given a set of points would like to construct a mesh of the surface (tessellation). In case you only need a solution for this problem: http://www.mathworks.com/matlabcentral/fileexchange/22185-surface-reconstruction-from-scattered-points-cloud-part1 Peter
From: adel on 27 Mar 2010 06:21 Hi Peter Thank you for your reply Here are the links again. Input http://www.postimage.org/image.php?v=gxBfKCJ ( http://s1.postimage.org/BfKCJ-645ca509f0b6c348e94789e4519653ac.jpg or http://www.postimage.org/image.php?v=gxBgz_J) Output http://www.postimage.org/image.php?v=gxBgg2A I already tried several things like gridata, trisurf, gridfit(written by John D'Errico)... But no success. ( I think because my shape is convex) Any help? Máday Péter <madapeti(a)gmail.com> wrote in message <0bdd8da8-74ee-4b3a-9dde-571737a3e265(a)k17g2000yqb.googlegroups.com>... > Hello > > Unfortunately your first link does not seem to work (at least for me), > but based on your description it seems to me that you given a set of > points would like to construct a mesh of the surface (tessellation). > > In case you only need a solution for this problem: > http://www.mathworks.com/matlabcentral/fileexchange/22185-surface-reconstruction-from-scattered-points-cloud-part1 > > Peter
From: John D'Errico on 27 Mar 2010 08:05 "adel " <adel.tekari(a)gmail.com> wrote in message <hokm6h$k6m$1(a)fred.mathworks.com>... > Hi Peter > > Thank you for your reply > Here are the links again. > Input > http://www.postimage.org/image.php?v=gxBfKCJ > ( http://s1.postimage.org/BfKCJ-645ca509f0b6c348e94789e4519653ac.jpg > or http://www.postimage.org/image.php?v=gxBgz_J) > Output > http://www.postimage.org/image.php?v=gxBgg2A > > I already tried several things like gridata, trisurf, gridfit(written by John D'Errico)... > But no success. ( I think because my shape is convex) You don't want to use gridfit, griddata, etc. They are not designed to solve your problem. You don't even need to use the tools designed to solve for a general surface from scattered points that Luigi provides. To generate the surface of a convex set of points, you use a convex hull. (Seems logical to me.) Find that in matlab already. Depending upon the dimension of your problem, help convhull help convhulln You can display the surface using trisurf. help trisurf HTH, John
From: adel on 29 Mar 2010 11:01
> You don't want to use gridfit, griddata, etc. They are > not designed to solve your problem. > > You don't even need to use the tools designed to solve > for a general surface from scattered points that Luigi > provides. > > To generate the surface of a convex set of points, you > use a convex hull. (Seems logical to me.) Find that in > matlab already. Depending upon the dimension of > your problem, > > help convhull > help convhulln > > You can display the surface using trisurf. > > help trisurf > > HTH, > John Hi John and thank you for your reply I tried the convhulln and the output is not what I want to have http://www.postimage.org/image.php?v=gxIFUei (http://www.postimage.org/image.php?v=gxIFUei&code=2) I need a regular 3d grid and not a triangulation. Any help? |