Re: reconstruction of 3D grid with connectivity

*To*: mathgroup at smc.vnet.net*Subject*: [mg91411] Re: reconstruction of 3D grid with connectivity*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Wed, 20 Aug 2008 06:23:23 -0400 (EDT)*Organization*: Uni Leipzig*References*: <g8gj4j$etq$1@smc.vnet.net>*Reply-to*: kuska at informatik.uni-leipzig.de

Hi, a) your assumption "when u and v are each incremented by given ustep and vstep" because ParametricPlot3D[] make a irregular triangle mesh you can see the mesh with plt=ParametricPlot3D[{Cos[phi]*Sin[th], Sin[phi]*Sin[th], Cos[th]}, {th, 0, Pi}, {phi, 0, 2 Pi}, Mesh -> All] b) the connectivity can be shown with GraphPlot[ Union[Flatten[(Rule @@@ Partition[#, 2, 1, {-1}]) & /@ Cases[plt, _Polygon, Infinity][[1, 1]] /. (a_ -> b_) /; a > b :> (b -> a)] ]] Regards Jens Narasimham wrote: > For surface ParametricPlot3D[{x = f(u,v), y = g(u,v), z = h(u,v)}, > {u,umin,umax,ustep},{v,vmin,vmax,vstep}] > > how to obtain the connectivity matrix (when u and v are each > incremented by given ustep and vstep), using Delaunay or Voronoi > triangulations? In this case there would be curved or skewed > quadrilaterals instead of triangles that discretizes the surface.When > connectivity matrix and coordinate matrix are given with each point > ID reference number, the surface should be reconstructed, i.e., > plotted, and/or Shown without again giving out the above command. > > Thanks in advance, > > Narasimham > >