Plankton, Inconsistency vertex-neighbour order

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Permalink Reply by Daniel Piker on April 1, 2014 at 2:22pm

Hi Lorenzo,

These numberings are all ordered in ascending order as you go around counter-clockwise, which is correct.

However, there is generally no guarantee that which of these neighbours comes first is 'consistent' (in the sense of surface u-v direction) across the mesh (and this is true for Rhino meshes, not just for Plankton), and on many meshes with irregular vertices there isn't any way to assign such a direction.

However, on these pages:

http://www.grasshopper3d.com/group/kangaroo/forum/topics/new-exampl...

http://www.grasshopper3d.com/group/kangaroo/forum/topics/new-tutori...

I've shown how to use some of the mesh tools I added in recent Kangaroo versions for sorting these directions when it is possible (there for Rhino meshes, but I guess something similar could be done for Plankton).

What is the intended use for this?

Permalink Reply by Lorenzo Greco on April 2, 2014 at 2:53am

Hi Daniel!

Actually what I was trying to do is to somehow replicate your WarpWeft tool.

I wrongly assumed that you wrote Plankton so to have consistent directions on meshes, so roughly speaking I iterated the 1-direction and the 2-direction to retrieve an uv mapping. Then I pick the points in the correct order to rebuild the mesh.

I hadn't exploited yet the functionality of the new Kangaroo, so I didn't know about WarpWeft and MeshDirection.

May I know roughly how does WarpWeft work? It works seamlessly :D

Permalink Reply by Daniel Piker on April 2, 2014 at 5:06am

Glad to hear the WarpWeft tool is useful.

It just starts from the first internal edge it finds and assigns it as warp, then assigns connected edges in an alternating fashion, then the same with the edges connected to those already assigned, and so on, iterating through the whole mesh this way (with slightly different behaviour at the boundaries).