SURFACE FROM POINTS (OUTCOME FROM KANGAROO) ???

Replies to This Discussion

Permalink Reply by SA on May 24, 2014 at 6:01am

Permalink Reply by David Rutten on May 24, 2014 at 3:00pm

There are two ways to create a surface from a collection of points:

1. The points are ordered in a rectangular pattern and you can directly create a nurbs surface from these points.
2. You can patch a collection of unordered points.

I can't really tell from your image whether (1) is possible. Please upload the actual point data as a GH file.

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David Rutten

david@mcneel.com

Permalink Reply by David Rutten on May 24, 2014 at 3:07pm

Please, just the points. You can internalize them in a single point parameter and upload only that. I have to install 3 plugins I don't have just to open your current file.

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David Rutten

david@mcneel.com

Permalink Reply by SA on May 24, 2014 at 3:21pm

Oooppssss !!!! Sorry dint realize that, here it is. Thanks a lot

Attachments:

• points.3dm, 312 KB
• points.gh, 20 KB

Permalink Reply by Daniel Piker on May 24, 2014 at 3:31pm

Kangaroo's geometry output will preserve exactly the data structure and ordering you give the geometry input, so that isn't a factor here.

You already have the correct point ordering because they originally came from a surface you created - the only issue seems to be that SrfGrid wants a different data structure, which you can get by shifting it like this:

It is confusing though, and took me a moment to figure out what was going on.

David - could the SrfGrid component maybe automatically take the last branch of the tree when it has multiple levels so this shifting wouldn't be necessary?

Permalink Reply by SA on May 24, 2014 at 3:54pm

Hi Daniel, thanks for jumping in. Even I was so puzzled at the end result. Surface from points results with both u values (11 and 66) are here. Although it should work perfectly with input of 11 but it dint so I started playing with the input.

Attachments:

• count 11.jpg, 224 KB
• count 66.jpg, 226 KB

Permalink Reply by Daniel Piker on May 24, 2014 at 4:00pm

Also - here's how to combine what I show above with Kangaroo:

Permalink Reply by SA on May 24, 2014 at 4:25pm

Hey, yes I know this can be very easily done with meshes but the whole point was to do it without the use of meshes (input or output). Hope David´s answer solves the puzzle of how to get those points sorted well into the polysurface.

Permalink Reply by SA on May 24, 2014 at 4:28pm

Daniel, the point that I am trying to make here is how to sort these points that I have got to get the final result. Or to kee the whole thing mesh free I have to substitute the SHIFT thing with something else.

Permalink Reply by Daniel Piker on May 24, 2014 at 4:53pm

The example above doesn't use meshes for the geometry input or output - the final result is a list of NURBS surfaces.

The meshes are just used as a convenient way of getting the connectivity of the springs for the forces - you could also do this by shifting the lists of points and connecting them with lines, but it would be exactly equivalent, only more complicated for no benefit I can see.

Permalink Reply by SA on May 24, 2014 at 5:03pm

Ok, I will try coz the points that I got before were expressing the tensile structure more in the real world. Coz I had the anchor points. 

That also reminds me to ask you (and great to have you here) can we instead of giving points as input give a curve as input. Kangaroo is such a fantastic tool and please forgive me to put this question across coz I am very new so kinda trying to develope tensiles but was trying if instead of anchor points in the top only actually can have a continuous ring. This is important to explore for the fabrication process.

Permalink Reply by SA on May 24, 2014 at 5:06pm

Coz if you see in the definition I had 6 anchor points in the top and 6 below (the usual way of putting up tensiles). And I must say after the stimulation the final points were in perfect shape (I just could not extraxt the surface from them). Now the point is what if I would like to have a ring continuous one in the top keeping the bottom points the same. Went through some Kangaroo literature and could not find a solution.