I have a doubt. Using iso2mesh i have created a 3d image of the brain sections. I want to import into abaqus so that i can mesh it finely. What are the steps to do that ?
the iso2mesh offers a wonderful environment to build tetrahedra meshes from volumetric voxel based grids. My question is: let's say I have a fine tetra mesh, which was generated from voxel based lattice. I'd like to have another, coarser tetra mesh, with the points/vertices given from the fine mesh. The process is as follows: I generate first the fine mesh, then select a set of uniformly distributed nodes from the fine mesh, and then with nodes I want to generate a new, "coarse" mesh. When I do it with Delaunay triangulation, I get also some regions/cavities meshed, which are actually (according to the lattice form) should be "free"
To sum up: given a mesh and original lattice, I'd like to have another coarser mesh with vertices being a subset of finer one.
Thanks in advance, Danila
yes, it is a problem of octave. In fact, the 3D graphics support in octave is quite inefficient at this point. Octave has historically been using GNUPlot as its plotting backend. Unfortunately, GNUPlot's 3D plotting feature is very slow, and limited. Recently, more efficient graphical backends were added to octave. But it is not mature yet, it has only the basic features.
To enable the new graphics backend, you need to type
backend('fltk');once in octave's environment, or
graphics_toolkit('fltk');if you are using octave 3.5+
this will generate nicer surface plots from octave.
I am running on Win7 using GUI Octave 1.5.4 + Octave 3.4.3. and have problem with handling graphics and accessing documentation.
To test the installation, I have run simple tests included in demo, for example, demo_grayscale_ex1. Octave completes the drawings but it is strictly a skeleton - just lines connecting nodes - no surfaces or colors. I can manipulate the viepoints - it is interactive but no colors or surfaces. This is repeated in many other tests cases. It would be nice to get images from the snapshot gallery ;-)
Questions: 1. How can I force the rendering of surfaces? Is it a problem of Octave? 2. How can I access iso2mesh documentation? Currently I am just keeping links in a bowser. Any way to add it to GUI Octave?
I understand that GUI Octave is not the scope of this forum,but I am just trying to resolve it, perhaps it is a simple fix ;-)
Thank you very much for making it possible to use iso2mesh - great help!
Controlling mesh density on the surface and internal volume is possible with iso2mesh. You may want to take a look at this FAQ.
Let me know if you have any difficulties using these settings.
I am trying to generate a Comsol Multiphysics geometry by exporting it as a mesh from Matlab, ... using the original faces generated with the matlab function isosurface. Have you tried exporting your meshes to comsol multiphysics? What path would you recommend?
Currently, iso2mesh is able to produce generic mesh data, i.e.node - x/y/z coordinates, elem - tetrahedral node list and face - surface triangle node list. It is up to the users to convert these generic data to whatever format they need. If you have detailed file format specifications, I would also be glad to code the converter and add it to iso2mesh.
I also have the plan to write an IGES/DXF converter as the first step, since most CAD software support these two formats. Unfortunately, I haven't found any good examples and documentations. If any of you can help, that would be great.
(just a side note: be careful about the last columns of iso2mesh output arrays, they are regional labels. You should decide whether to use them or not when you write your converter).
Have you tried exporting your meshes to comsol multiphysics? What path would you recommend?
By the way, Thanks very much for sharing iso2mesh.