WeaverBird
WeaverBird 0.2 is a beta plug-in for topological transformations in Rhino 4.0 and Grasshopper 0.6.0059. It helps smoothing, modifying and preparing meshes for rapid manufacturing technologies.
Main topological commands:
Catmull-Clark smoothing (wbCatmullClark). Calculates the type of mesh-based recursive subdivision described by Edwin Catmull and Jim Clark, at first in 1978. The resulting mesh always consists of quadrilaterals.
Split mesh into Quads (wbSplitQuad). Calculates a new mesh, which is formed of only quads. It is topologically equivalent to the Catmull-Clark subdivision.
Loop smoothing (wbLoop). Calculates the type of mesh-based recursive subdivision described by Charles Loop, at first in his Mathematics thesis in 1987. The resulting mesh always consists of triangular faces.
Split mesh with inner face (wbSplitPolygons). Places a new face departing from the middle of each original face edge. Caps the whole with Sierpinski triangles.
Sierpinsky Triangles subdivision (wbSierpinskyTriangle). Places a triangle in each corner of a mesh face. The mesh will have one more hole per face.
Frame (wbFrame). Computes a new mesh with higher naked edge count, where each face has a new hole in the center and resembles a picture frame. The resulting mesh always consists of quad faces.
Carpet (wbCarpet). Computes a new mesh with higher naked edge count, where each face has a new hole in the center. The resulting mesh always consists of quad faces, and can be used to compute a Sierpinski carpet.
Window (wbWindow). Replaces each original mesh face with a new one, reconstructed on the inside. Each face has the same number of sides as the original one.
New mesh primitives definitions:
wbPrism, 
wbAntiPrism, 
wbPyramid, 
wbDiPyramid
Additional commands:
- wbOptions. To see the main log, set up the threading model, control the maximum time a single operation is allowed to take, and set options for the Loop subdivision scheme (to use Loop’s receipt or Warren-Weimer’s one).
- wbProperties. Opens a window with topological information about any mesh object in Rhino. Exposes triangular and quad face counts, edge count, current and welded vertex counts.
Older versions
For Grasshopper 0.6.0043
For Grasshopper 0.6.0019.
September 1st, 2009 at 5:03 pm
This looks awesome! can’t wait to try it out
September 3rd, 2009 at 10:18 am
started with it today. so much more investigation to do, but here’s what i whipped up : http://www.flickr.com/photos/stufingerhut/3884032978/
September 3rd, 2009 at 2:41 pm
It looks good. :) Thanks.
September 9th, 2009 at 2:42 pm
Thanks Giulio, great work!
September 10th, 2009 at 10:41 am
Don’t work in Rhino4 (Italian version). Message: (Unknown command) Comando sconosciuto:_wbCatmullClark
September 11th, 2009 at 9:51 pm
Hi Marco, I sent you an email in Italian to try and help! How did it go? Giulio
October 17th, 2009 at 9:58 pm
Giulio,
Like all of the tools you have shared, they are truly useful. A great contribution to GH! Thanks!
luis
October 30th, 2009 at 6:27 am
Totally agree with Luis Fraguada this tools brings grashopper to another level keep up the good work !!!
November 4th, 2009 at 1:01 am
Thank you buddy!
December 2nd, 2009 at 12:47 pm
Amazing work!
December 31st, 2009 at 3:26 pm
[...] strategies. Further Catmull-Clark mesh subdivisions thanks to Giulio Piacentino’s WeaverBird Plug-in for Rhino and Grasshopper. Below are examples of the subdivisions generated. [...]
January 2nd, 2010 at 2:29 am
[...] lately we have been watching the appearance of some grasshopper plugins like Rabbit 1.0 , WeaverBird and Modetools developed by independent design studios, I predict this tendency will grow this year [...]
January 31st, 2010 at 11:33 pm
amazing set of features. i would just say that you should add a unify normals bool to the join mesh component.