Grasshopper

algorithmic modeling for Rhino

# Wireframe to solid operations

Hi ALL

That's an issue I have been willing to know for very long time. Having a wireframe (lines and curves) model, how can I convert into a ONE SINGLE CLOSED SOLID (for 3d printing). Piping and adding spherers at the vertices doesn't work.

Has anyone find a solution to this problem, does anybody know other ways to achive that. I dream an algorithm that thikens the lines and curves and solves all the unions.

P.D: I've allways thought that was a hidden secret very well protected...but maybe there's no straight solution.

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I have done a bit of research into this problem and come up with two solutions. One is to solve for joints at the vertices and weld with meshes along the struts (lines), and then smooth the solution. I just posted this in another thread, but I may as well share here too - http://ledatomica.wordpress.com/2010/08/31/space-framing/ - The results are occasionally a self intersecting mesh but depending on your 3d print method they will still print successfully.

The second method (as discussed) is isosurfacing, although I have not been able to find a quick enough isosurfacing method within grasshopper. The simplest way I have found to mesh line networks is to use Pflow and Pwrapper in 3ds max. Both are very fast solvers with some useful documentation to be found on how to get them to work.

Hi Gwyllim

This is fantastic! I have been working on a fast way of thickening lines for structural analysis in GSA but have been struggling a lot. Would you be happy to share this definition? Email ismunrojack@gmail.com

thanks

jack

brep_shells.gh

This definition is similiar to the one on LAN site called gh_shelling (thanks Luis). It should work fine as a 3dprintable version of the original wireframe.

Some notes about this problem - as I noticed, it is very often discussed an has some practical values.

1. Shape, which produces an ideal circle after CC-subdivision is a hexagon, and hexagonal tubes are ideal for long bones, if you have plans to get subdiv.

2. This leads to solving such problem - getting complex joint blending to hexagonal sections, which may be blended without any pain.

3. There may be a lot of additional information about your joints and their shapes, so, I seem, it requires complex approach to each case - you may solve joints by implicit field sampling, but bones - by hexagonal tubes, with smart blending of different-count slices, or you may define template planes (like voronoy-cells walls) for bases, or you may try to build another best solution, which is named "anything else" :)

4. My proposal is next - to start with tube/sphere solution, scatter points at joint area (excluding overlapped surfaces areas) and perform smoothig/relaxing steps with more smoothing, if points has too much different tubes around, and restore/simplify target surface. It is most naturalistic approach :).

Thank you.

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