Gone in 10 milliseconds (the Umbrella sticks case)

Well friends,

A fellow GH user (Nicknamed ... hmm ...User) initiated some puzzles about vector "centroids" (add unitized vectors in plain English) - he calls them "Umbrella sticks".

Read this first:

http://www.grasshopper3d.com/forum/topics/cross-product-of-multiple...

I've got involved since I'm doing "similar" things for tensile membranes, weird/complex trusses and the likes. So this C# code is in fact a "cut and paste" thing from a variety of other cases under development right now.

So, I'm starting a "parallel" similar thread ... because a lot of updates (faster code, more bugs, more divisions by zero == progress) are under way.

PS: test data are internalized (but better safe than sorry: use Rhino file as Plan B).

PS: for User: Display Surface Normals and compare VS "centroids" (sum of triangle unitized Normals).

best, Peter

Attachments:

surface-subdivide-test10E-FINAL.gh, 395 KB
surface-subdivide-test10.3dm, 147 KB

Replies to This Discussion

Permalink Reply by Hannes Löschke on January 26, 2015 at 1:50pm

Hey,

for this extreme situation, the adjustment is actually worse. It's good to improve orientation at the edges. Since your umbrellas are all interior vertices, you can just use the N output without any further adjustment. That's the average of the adjoining face normals.

Permalink Reply by James on March 9, 2015 at 5:15pm

I was staring most recently at your Umbrella workings and I was wondering if you had developed the C# for a closed surface version.

Hannes' def does work for my closed surface(s) however it unfortunately re-orders my lists causing node identification to be... unidentifiable. I only ask as I need my list for many other things and it would be just super if I could keep it.

Peters definition is in orange (is it possible to find the sum of the vectors that come in contact with the vertices) and the desired umbrella stick (obviously) is in white.

Thanks

P.S. My lawyer says that this may be grounds for a case ;)

Attachments:

A_new_hope.gh, 96 KB

Permalink Reply by peter fotiadis on March 10, 2015 at 1:40am

Er...my dear Watson:

you feed the mother of all scripts (he he) WITH THE WRONG stuff: by Lists I mean surface lists (that are further divided into pieces from where the umbrella things are extracted) and NOT surface pieces that in fact are the division results (so to speak).

Moral: garbage in > garbage out.

PS: a much more capable thing (Version 10F) is under way operating either in division mode or ... in "get these and do the maths for me please" mode (as in your case).

Moral: long is the path (and hilly).

Permalink Reply by peter fotiadis on March 10, 2015 at 2:09am

PS: 10F starts with the right thing: a node connectivity data tree > the rest are trivial. A 123,45 years unlimited user satisfaction guarantee is provided free of charge as well (or is it 123,45 milliseconds?).

PS: What have to do law suits with this Noble Forum? Fire them all and hire some blonde secretary.

Permalink Reply by David Rutten on March 10, 2015 at 2:24am