rationalizing "dirty" mesh intersections

Hi to all!

I come with a question I have not been able to solve yet. I am doing a simple contouring of a triangulated mesh. The contouring is via section planes on an evaluated line. Such mesh isn't necessarily neat given it came from a 3D scanner point cloud.

Files attached. I hope you are able to point me in a better direction!

found intersections at chosen parameter

curves from intersection result aren't continuous where mesh has discrepancies

Connect component does not necessarily fix all curves

I have attempted rebuilding curves, simplifying, interpolating points, smoothing polylines, removing points, populating geo, etc. and have not had success.

I know cleaning up the mesh in another program would fix the mess but the intention here is to re-apply the contouring to multiple scanned fragments that might or might not have similar (or worse) discrepancies such as holes, overlaps, and self-intersections.

Am I confined to repairing curve by curve or is there a smarter way to 'repair' them all based on their plane location(s) that I am missing?

Thanks in advance for any comment or ideas - let me know if files don't work.

Attachments:

meshfragment.3dm, 905 KB
rationalize_intersection.ghx, 133 KB

Replies to This Discussion

Permalink Reply by peter fotiadis on April 28, 2017 at 1:00am

As you already said ... the best solution by 1M miles is to use a dedicated subdivision (mesh) app to do the required clean/repair/whatever kind of job (say: MeshLab (free + many many bugs), Modo (not free + the best), ... , etc etc). BTW: you can use scripting in Modo (the approach on duty for that is -as usual- genius).

Other than that theoretically speaking there's various ways to address (or to attempt to address) situations like these but none of them is easy, none of them is possible without coding and none of them has actually any meaning (other than the art of pointless).

Permalink Reply by RENE on April 28, 2017 at 4:34pm

Thanks for taking the time to reply Peter. Are you able to point me in a specific direction for the modo scripting that could help me work this out? What specifically are you referring to? Can modo clean up curves resulting from mesh contours?

Many thanks!

Permalink Reply by peter fotiadis on April 29, 2017 at 12:12am

Well ... give some clues on your level with Modo (and the build on duty). Are you - in general - familiar with Modo's scripting approach? Or can you find a friend who's experienced enough to do it for you? (it's like saying that you want to do something with GH: 1Z ways to attempt it depending upon the knowledge of the product).

BTW: Contours/"Sections" et al are just a by-product: if the source is garbage then expect garbage as results as well. Even if you could "clean" the curves (as I said: possible especially via code) ... they would still refer to a non existing donor source object.

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