No, I don't think Delaunay is a good approach for this. This shape requires a true 3D algorithm. Actually, the shape looks like it might be the result of a Marching Cube process, and as always, it's usually much easier to find good algorithms for very strict shapes than for generic ones. With such a high degree of symmetry, I suppose a custom solution would give you a better result that you could possibly achieve otherwise.
-- David Rutten Robert McNeel & Associates On Dec 2, 4:23 pm, visose <[EMAIL PROTECTED]> wrote: > What would be the best approach to create the skin for this > shape?:http://grasshopper3d.googlegroups.com/web/schwartz2.jpg > Discussed in this > thread:http://groups.google.com/group/grasshopper3d/browse_thread/thread/fde... > This skin in the screenshot is done by creating panels over several > point grids (and culling the unwanted panels). You can't create this > object by a continuous surface (i think). The problem is that with > this method some panels overlap. The superposed point grids create an > unordered point cloud that could be triangulated. > > I was thinking that maybe if the delaunay triangulation had a distance > threshold, and the points where close enough on the imaginary surface, > it would only triangulate on the right spots and wouldn't create > triangulations all over the place (well, maybe on edges but the > curvature is continuous in this example). In this case, i don't think > there's a useful guide geometry. > > On Dec 2, 2:47 pm, David Rutten <[EMAIL PROTECTED]> wrote: > > > Delaunay is pretty easy, but it's a 2D algorithm so there's always > > some extra stuff that needs doing when using it in a 3D environment. > > This is why the PoistSetReconstruction plugin uses Guide geometry, to > > convert a 3D point cloud into a 2.5D point cloud. > > > Once Delaunay is finished, it's quite easy to bolt a 2D voronoi cell > > solver on top. 3D voronoi is much harder to do efficiently. It's not > > as easy to discard certain points, which means you end up doing a lot > > of unnecessary solid boolean operations slowing the whole thing > > down... > > > -- > > David Rutten > > Robert McNeel & Associates > > > On Dec 2, 2:29 pm, visose <[EMAIL PROTECTED]> wrote: > > > > Very nice. I also used voronoi a couple years ago as one of the > > > parameters of urban planning for a school project. The realtime > > > manipulation of grasshopper would've come really handy. Is the > > > delaunay algorithm much harder to implement? I'd like to use it to > > > mesh some unordered point clouds. > > > > On Dec 2, 8:29 am, Dimitrie <[EMAIL PROTECTED]> wrote: > > > > > hello oompa, > > > > as i was also needing some sort of space-partitioning algorithm for an > > > > urbanism project tomorrow, i tried and managed to pull up a > > > > grasshopper voronoi node, based on david's algorithm > > > > you can check it out > > > > herehttp://dimitrie.wordpress.com/2008/12/01/grasshopper-voronoi-diagram/ > > > > > On Nov 25, 7:44 pm, oompa_l <[EMAIL PROTECTED]> wrote: > > > > > > is this possible with grasshopper yet? maybe it always has been...if > > > > > anyone has any clues on this, I could use it right now... > > > > > > thanks!
