help with edge curves

I am trying to find the edge curves from a solid union in order to extrude a closed poly surface (last photo). I am trying to build a support system/lattice for Voronoi extrusions. I was modeling this all manually in Rhino but now I want to apply this to any surface (see iso drawings of bracelets) and control the dimensions to match 3D wax printing tolerances.

I am very new to grasshopper. Please be kind. I am sure I am doing a bunch of stuff wrong.

Replies to This Discussion

Permalink Reply by peter fotiadis on December 22, 2016 at 9:01am

See attached (BTW: doable with native components except the offset a BrepFace [at once] both sides Method).

In fact the choice of the "outBrep" to work against the "inners" is not elaborated at all (region containment tests are the way to go) but this approach used works in this simple case. Curves must be valid, planar and closed (if not they are excluded from the collection). If no such curves are found a message appears and the result is ... nothing.

Attachments:

Curves_to_regions_entryLevel_V1.gh, 18 KB

Permalink Reply by Arthur Hash on December 22, 2016 at 9:57am

Peter. Thank you. I am having a hard time understanding what your definition is doing.

I am a super beginner. My definition is probably all wrong. I keep going back and trying new things. In the end I would love to generate this geometry to flow along a surface.

Attachments:

padsbracelet.gh, 97 KB

Permalink Reply by peter fotiadis on December 22, 2016 at 10:24am

And this is a more "complete" (so to speak) example on that matter .

BTW: For avoiding some complex (by "the book") situations Morph a flat collection to a given surface. Of course the "connections" would be a bit weird ... but this is an "elastic" decorative object, no?

PS: Unfortunately I do business mostly with code (a totally inappropriate way for a beginner [or anyone not familiar with coding], truth to be said). Let's hope that some other good Samaritan could provide a solution using solely GH native components.

Attachments:

Curves_to_regions_entryLevel_V2.gh, 127 KB

Permalink Reply by Arthur Hash on December 22, 2016 at 10:26am

I think my reply got cut off. hopefully it is all there now (my reply above).

Thanks for your help.

Permalink Reply by peter fotiadis on December 22, 2016 at 10:45am

BTW: If you don't use Morph for going from "flat" to "curvy" ... then the supporting mini lattice requires a different approach than (a) Delauney (proximity or ball pivot) AND (b) the curves to regions way used as above. Not a very easy task for an absolute beginner, mind.

Permalink Reply by Laurent DELRIEU on December 22, 2016 at 12:42pm

Here a version with GH components

PS: Your bracelet is very beautiful.

Attachments:

padsbracelet_LD.gh, 63 KB

Permalink Reply by Arthur Hash on December 22, 2016 at 1:02pm

Ahhhh! Thank you! I see what where I messed up.

Permalink Reply by Laurent DELRIEU on December 22, 2016 at 1:56pm

I continue it a bit and I add Sporh command to bend the bracelet, just the main curvature.You choose an angle on bend, 360° full closed, 0° nothing.

I tried to join solid without chance. Surely some orientation not good. I added an offset from BowerBird BB, it comes from Clipper Library. Far better than Rhinoceros for offsetting polygon.

I put a dam in Sporph because it is a bit long

Permalink Reply by Laurent DELRIEU on December 22, 2016 at 2:06pm

My dam wasn't good !

A better one

Attachments:

padsbracelet_LD2.gh, 39 KB

Permalink Reply by peter fotiadis on December 23, 2016 at 12:48am

Happily Laurent did Plan B.

Just for the record this allows more efficient mesh control (red group) and keeps the slow part deactivated until a thickened mini-lattice is required.

Meaning that up to this phase the thing is real-time:

Attachments: