Sort Faces according to normals

Hello World !

Today, I've tried to make a tiny code that could sort faces of a brep according to their normals.

I'll first explain my code and after ask why i'm not already satisfied with it.

1. I deconstruct the Brep to understand which faces are planar which aren't.

2. I get the normal vector of each planar faces.

3. I deconstruct N into its component parts,

4. I put them on absolute values because i need to sort them by their parallelism in space not their actual side.

5. I merge the values together and create a set of only unique elements.

6. Partition the list by the third of its length

7. Flip matrix and concatenate the 3 values to get the unique code of their parallelism.

8. After, with another create set and a sift component i can sort them according to their N or -N direction.

The problem is that i don't want to use a sift pattern because it's not a very parametric way to get data; With it I have to manually change its number of outputs, I need a component that gives me x number of lists of surfaces parallel to one another. Like a "dispatch multiple component" but only with one ouput ?

Also I'm thinking that this code could be much clever if there's a tolerance parameter to put similar surfaces into the same lists even if their not perfectly parallel one to another

Thanks in advance for your help and your time.

Attachments:

sortFaces2.gh, 24 KB

Replies to This Discussion

Permalink Reply by peter fotiadis on May 8, 2017 at 4:50am

Well ... the bad news are that I'm losing my touch with native components with an alarming rate.

The good(???) news are that I have what you want.

How it works: for each Brep in the bList (null/invalid stuff is discarded automatically) it creates a "reference" Box according the planeNormal values (that has 6 faces and 6 normals). For clarity these are displayed as wireframes (in red). Then it classifies each planar BrepFace accordingly (the min normal angle VS these 6 normals). Faces are stored as Breps in a DataTree. On that ... the second dimension corresponds 1:1 to the reference box "faces"/sides.

Use the "how it works" demo part to get the gist of what's happening.

For instance:

Or using Me (with all due modesty) as a List test:

Attachments:

BrepFace_normalsSort_VS_Box_V1.3dm, 302 KB
BrepFace_normalsSort_VS_Box_V1.gh, 128 KB

Permalink Reply by Nenov Ivo on May 8, 2017 at 7:18am

Thanks Peter but I'm kind of totally lost when i see some C code... and I like to understand completely the tools I'm using hehe

Is there a way to have a kind of "Sift" or "Dispatch multiple" component with only one output that gives lists with surfaces with the same parallelism...

PS: please no more C... I feel so dumb every time i see some...

And I tried to use your code but when I put geometry instead of breps into the inputs it doesn't work... no more C, GRASSHOPPER please

Permalink Reply by peter fotiadis on May 8, 2017 at 7:30am

Well ... the bad news are that day in day out I'm more and more away from components (time to take a 5 year break as well?). Let's hope that some good Samaritan can resolve this the other way.

PS: Out of curiosity what sort of "geometry" have you tried? (I do hope not a mesh [besides the thread title states: faces from breps]).

Permalink Reply by Nenov Ivo on May 8, 2017 at 8:03am

Those kind ;) breps and surfaces

Permalink Reply by peter fotiadis on May 8, 2017 at 8:11am

Can you e-mail (or attach here) this thingy (or some representative portion of it) please? (Curiosity killed the cat)

Permalink Reply by Nenov Ivo on May 8, 2017 at 11:10am

I don't have your mail... and I'm not putting ongoing projects on forums hehe

Send me your mail I'll be very happy to have a though about my future turkish/bulgarian not isolated toilets !

Permalink Reply by peter fotiadis on May 8, 2017 at 11:55am

... I'm not putting ongoing projects on forums ...

Yikes ... you become a real pro then (send me some autograph ASAP) .

Anyway ... due to a very rare crisis of altruism and humanitarianism (things more or less totally unknown to the Merciless Lord of SardineLand) I've added a component solution as well on that V1A attached. Note: the IndexOf component does bananas (replaced with you know what) ... and the last bad thingy is there because I'm out of espresso.

The pasta part works as the C# ("almost", anyway) with boxMode = per Brep (that's the new option).

Attachments: