multiple surfaces from lines

Hey guys I was wondering if there is some logic out there for creating multiple surfaces from curve networks , something like the mesh from lines component in weaverbird, bot something that will also intake more the 4 nodes.

attached is a picture outlining the surface patches I want to achieve.. of course the first' step is getting them to become polylines. I'm hoping for some inner logic rather than projecting the curves to a plane and extracting the information from an intersection..

Thanks..

Attachments:

SURFROMLIONES.jpg, 70 KB

Replies to This Discussion

Permalink Reply by peter fotiadis on March 1, 2016 at 12:54am

... more than 4 nodes...

If you mean that you want to make a graph with some way (i.e. vertices connected with others) and then do something with that (having the connectivity Trees [v to v, v to l etc etc] on hand):

There's no "direct" Method that takes more than 4 points (or edges) to make a single face Brep [ i.e. one BrepFace] or a NurbsSurface.

Patch on the other hand ... well ... it's a bit tricky.

Permalink Reply by kipodi on March 1, 2016 at 4:15am

I managed to solve it by projecting the curves to the xyz plane and splitting a surface by these curves and the extracting the z value from the points that are on the same x,y and rebuilding with their corresponding z.. its an ugly method which basically uses the split by curves logic which probably has the algorithm I'm looking for embedded in it.. there has to be a better way I would assume..

Permalink Reply by peter fotiadis on March 1, 2016 at 5:04am

Well ... you can try the Plane Fit thingy as well if the "graph" is not on World.XY (the component used for the other thread of yours with regard sorting chaotic points).

Permalink Reply by kipodi on March 1, 2016 at 7:27am

if I had the nodes nested correctly in a tree I could sort the list for the connectivity of the polylines.. the question is how to to go from a flat list to a nested list of the panel nodes..

Permalink Reply by peter fotiadis on March 1, 2016 at 8:38am

I've lost you: what means nested nodes? what means nested List?? (you tell me).

Solution(?): Get SandBox, make a graph (some lines connected that, is) and then try to get the gist about what connectivity trees mean (the most critical thing in engineering no matter what you do: trusses, panels, things, other things, cats, dogs ...etc etc).

Permalink Reply by kipodi on March 3, 2016 at 9:46am

OKKK! so the sandbox thingy is what I was lacking.. the logic to extract edges for each panel separately from a flat list of lines... for the connectivity I can do the flow along curve later. thanks!!

Permalink Reply by peter fotiadis on March 3, 2016 at 11:06am

I always check everybody in my practice with regard connectivity matters - above all: I couldn't care less about what they are doing (life's short + why bother? + who cares? [not me]) BUT fully understanding what these things mean is the Holly Grail of engineering.

The ultimate challenge for you: if N cats are connected with M dogs ... by what means can we find the age of a rat?

Permalink Reply by Laurent DELRIEU on March 1, 2016 at 6:07am

I did something like you image. As your curves are in 3D not 2d it will not work.
http://www.grasshopper3d.com/group/kangaroo/forum/topics/envelop-of...
In order to have a topology you need a vector on each node, for me it was Z, curves are on xy plane. A vector on each node enable to select the good road, at each intersection (point node) the algorithm search the more left or right turn, etc until it is an end (dead end, cul de sac) or we arrive at the beginning.
Hope it could help a bit!

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