Sorting points mesh

Hey guys,

I'm struggling with i thought would be something simple, but turned out rather difficult. I've converted a brep (consisting of 2 surfaces) to a mesh surface with a U and V subdivision. I'm trying to get the vertices in the 'right' order, i mean left top to right bottom, like the order from the divide surface component.

Instead this happens (see attached)

There should be like an easy trick to figure this out, my mesh is all quad based, so no funky stuff. Ive tried flattening and sorting points, but that didnt work out.

Thanks in advance for your advice!

Attachments:

ordermesh.jpg, 414 KB

Replies to This Discussion

Permalink Reply by Danny Boyes on March 28, 2011 at 10:56am

Have you tried the Flip Matrix component (located in Sets>Tree)?

Permalink Reply by Arie-Willem de Jongh on March 28, 2011 at 11:43am

No it doesnt work, it just flips the U and V. Im trying to reorder the points from left top to right bottom (like the divide surface component does let's say). The order in the first image is off sometimes, maybe that wasnt clear, look at point number 44 it jumps 'weird' to point 45.

The example attached is the preferred order.

Thanks for the fast response!

Attachments:

ordermesh01.jpg, 496 KB

Permalink Reply by Tudor Cosmatu on March 28, 2011 at 12:29pm

did you try to use sublists? cause to me it looks like a flattened list of points.

U can (for this last example) stick a sublist component for your point list and make domains like following ( 0-8, 9-17....,126-134), in the end you ll have a tree with a certain number of branches each containing one row of points.

Permalink Reply by Danny Boyes on March 28, 2011 at 1:26pm

I see the problem now. I have a solution that works for a single surface where the mesh Vertices get jumbled but I'm still working on a BRep made of two surfaces.

I'll get back to you on this.

Permalink Reply by Pieter Segeren on March 28, 2011 at 12:54pm

Hoi Arie-Willem, I think you'll need the pathmapper, though I'm not very good at this yet, I've made a little definition that might help.

Attachments:

reorderpts.ghx, 65 KB

Permalink Reply by Arie-Willem de Jongh on March 29, 2011 at 7:12am

The problem is that the initial order of the points is already 'messed up'. If the points were already ordered in some way, like row by row, of course i could do whatever i want. Using pathmapper/sublist or series to get the desired effect like you showed in your example Pieter thanks for that.

The problem is the initial order is weird. If you could find a solution Danny that would be awsome,

Thank you all!

Permalink Reply by Pieter Segeren on March 29, 2011 at 7:37am

Okee Arie-Willem, could you upload your definition so we can have a look into why the order of your initial points is weird?

Permalink Reply by Arie-Willem de Jongh on March 29, 2011 at 8:48am

Sure pieter see attached.

It requires weaverbird mesh components installed for grasshopper (http://www.giuliopiacentino.com/weaverbird/)

this is just an example file with 3 curves and when lofted turned into a brep. I need the surface to match the curve lines. My original file is more complex of course, but this is in simple the problem I'm facing,ordering the points row by row, ascending, like the subdivide surface. It needs to stay a mesh because of topological reasons.

Good luck and thanks again!

Attachments:

BrepMeshPoints.3dm, 25 KB
BrepMeshPoints.ghx, 145 KB

Permalink Reply by Pieter Segeren on March 29, 2011 at 11:03am

Hi Arie-Willem,
I haven't been working with meshes a lot, and I do not understand how the meshpoints are numbered or sorted if you wish, even if it's unjoined meshes. Hopefully Giulio himself can help you out, and teach us something more about this ...

Permalink Reply by Arie-Willem de Jongh on March 29, 2011 at 11:14am

I found a component which keeps track of the vertices numbers, called face vertices. I didn't see that one before. With this component it doesn't really matter which sequence the vertices are ordered. If your mesh is quad based it remembers the number which you later on can refer to.

Im going to struggle a little bit further and ill post my findings.

Cheers,

Permalink Reply by Pieter Segeren on March 30, 2011 at 8:47am

Hi Arie-Willem,
I've found a discussion that just might apply to what you are doing too. (if your surface isn't too wavy) I thought the 2d-sort.ghx by David Rutten himself might give more insight.
http://www.grasshopper3d.com/forum/topics/sort-mesh

Permalink Reply by Michael Clarke on January 23, 2013 at 7:29am

Hi Arie-Willem,

Did you solve this. I know this was quite a long time ago however I have been needing a similar thing. Using the script that Pieter posted above, 2-d sort I have tried to change some of the inputs to sort points by U and V values rather than along a guide or by cartesian co-ordinates which may help you. You may need to change the multiplier within the function if it doesn't quite work for you.

I posted the solution on this discussion: http://www.grasshopper3d.com/forum/topics/sort-mesh?commentId=29852...

Let me know,

Michael