Wish - Brep Closest Point with output plane

Replies to This Discussion

Permalink Reply by Pieter Segeren on December 12, 2014 at 5:59am

Hi Dani, I think all data you need is the point and the closest point to create the plane:EDIT: whoops: got the vector reversed: change P.X - cp.X in cp.X - P.X etc. Sorry.

Attachments:

• BrepClosestPlane_PSG.gh, 15 KB

Permalink Reply by Daniel González Abalde on December 12, 2014 at 6:24am

Thanks for the reply, Pieter. But the method to build a plane with a point and a vector does not correspond to the normal of the surface on the brep. 

Permalink Reply by Pieter Segeren on December 12, 2014 at 6:35am

Well, I'm still too foggy in my brain from all the snot (excuser le mot), I should be in bed... But I think the direction should be okay, otherwise it wouldn't be the closest point, right? Forget my edit from before. I'm off!

Permalink Reply by Daniel González Abalde on December 12, 2014 at 6:47am

hahah
Well, when the closest point is very close to an edge, the normal direction must be perpendicular to one face, with plane (pt, Vect) does not happen.

Permalink Reply by Michael Pryor on December 12, 2014 at 7:50am

personally I think its not necessary as its not always needed. That's why the evaluate component exists. If anything uvP makes more sense to be part of that component. 

Permalink Reply by Daniel González Abalde on December 12, 2014 at 1:08pm

The breps have UV coordinates? I mean, without being those of their separate surfaces.

Well, it is not necessary but neither superfluous, as had the def. I thought... why not add the normal plane (or uv's) to the component for a future version?

Permalink Reply by Michael Pryor on December 12, 2014 at 1:35pm

I meant along the lines of Danny. UVp for that surface of that brep.

Permalink Reply by Danny Boyes on December 12, 2014 at 8:09am

I used this component this week and my wish at the time was to identify which surface of the BRep the point was related to so that I could then do things with that surface based on which point it was closest to.

NB: In my mind this makes complete sense :S

Permalink Reply by Andrew Heumann on December 12, 2014 at 12:38pm

Here's a script to output the normal vector of the BRep at its closest point - this should be sufficient to retrieve the plane. 

Attachments:

• Brep CP w Normal.gh, 38 KB

Permalink Reply by Daniel González Abalde on December 12, 2014 at 12:57pm

Thanks Andrew ! But I found a bug... Resulting vector is perpendicular to the normal, sometimes.

I don't unterstand c# yet, so I can't write over this script.

Permalink Reply by Andrew Heumann on December 19, 2014 at 3:20pm

Yeah, this is a strange behavior of RhinoCommon's own "Brep Closest Point" function. I've modified the script to get around it. Hopefully this is closer to what you need. 

Attachments:

• Brep CP w Normal 2.gh, 40 KB

Permalink Reply by Daniel González Abalde on December 19, 2014 at 4:49pm

Thanks Andrew, I will store in my panel components ;)