Detect "touching" Polysurfaces

Replies to This Discussion

Permalink Reply by Joseph Oster on August 15, 2017 at 10:10am

You didn't post your model so I had to create my own...

Attachments:

• touching_polysurfaces_2017Aug15a.gh, 11 KB

Permalink Reply by Joseph Oster on August 15, 2017 at 5:47pm

Added two "filters" - best to preview one or the other, they are connected in series:

1. the green group ("have neighbors") has a slider to show all (1) or, as you approach zero, only those with more and more neighbors.
2. the white group ("my neighbors") has a 'list idx' slider to choose one of the filtered results and show all of its neighbors.

Attachments:

• touching_polysurfaces_2017Aug15b.gh, 29 KB

Permalink Reply by Joseph Oster on August 15, 2017 at 6:19pm

P.S.  'Scale' in the white group is superfluous and should be skipped/ignored.

P.P.S.  Oops...  that broke a feature - too hasty.

Attachments:

• touching_polysurfaces_2017Aug15b.gh, 20 KB

Permalink Reply by Joseph Oster on August 16, 2017 at 9:04am

Fixed the cosmetic highlighting feature (yellow group inside "my neighbors") and modified the "FRAGMENTS" (blue group) to clarify the distinction between data (the "fragments") and the code to answer the original question.

Bumping the 'ArrBox' dimension from 5 up to 7 is still reasonably "fast" - ~6 secs.

Attachments:

• touching_polysurfaces_2017Aug16a.gh, 35 KB

Permalink Reply by Joseph Oster on August 16, 2017 at 10:52am

Better.  With 'Jitter' on the arrayed fragments, before 'Reduce'.

Even better(?) would be to distinguish between neighbors who have adjacent faces (overlapped surfaces) vs. only shared edges?

Attachments:

• touching_polysurfaces_2017Aug16b.gh, 36 KB

Permalink Reply by Petras Vestartas on August 15, 2017 at 10:54am

There are several things to get faster performance

1. Use meshes

2. Sort closest pairs, rtree is always good option. If you do not care about speed, you will check intersection between each and and the rest.

3. Fastest method with decent output is:

    Line[] line = Rhino.Geometry.Intersect.Intersection.MeshMeshFast(x, y);

    if(line.Length > 0)
      A = true;

Attachments:

• MeshFast.gh, 20 KB