mesh intersection problem

Hi everyone!

Im working on a script that generates you intersection curves from a terrain+buildings on it. The terrain and buildings are together as one open mesh.

When I try to intersect my meshterrain with the intersection planes through the Intersection.MeshPlane method I get unproper intersection lines (see image attached).

I need a CLOSED polyline for the script to work.

The Intersection.MeshMesh method unfortunately gives worse results.

Is there maybe a possibility to convert the meshterrain to a nurbs surface? From previous tests I figured out that the Intersection.SurfaceSurface method works much better, but I cant convert the meshterrain to a nurbs surface.

Thx for help and hints

Best

Attachments:

intersection curves.jpg, 1 MB

Replies to This Discussion

Permalink Reply by David Rutten on October 24, 2012 at 12:40pm

What about Intersection.MeshMeshFast?

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by hjalmar schmid on October 25, 2012 at 1:05am

Thx for the help so far, but the MeshMeshFast somehow gives similar results, lots of lines which are missing small pieces. Could it be that the mesh is actually too large for this operation? It has almoust 200'000 polygons. Therefore also the meshToNURB Rhino command would be impossible to apply without splitting the mesh into many smaller pieces, because it works only up to 20'000 mesh faces

Attachments:

intersections.3dm, 1.9 MB

Permalink Reply by djordje on October 25, 2012 at 5:16am

Maybe you can convert the mesh to nurbs using an additional plugin:
http://www.resurf3d.com/Mesh2snurbs.exe

And then intersect your new nurbs terrain with intersection planes.

Permalink Reply by David Rutten on October 25, 2012 at 5:23am

I think it may be a bug. You'll need to post the mesh though otherwise we cannot find the bug.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by hjalmar schmid on October 26, 2012 at 1:29am

http://www.2shared.com/file/owmQZ1uC/meshterrain.html

I guess the bug somehow derives from the fact that I did a boolean difference with the terrain and building objects. When I apply the mesh intersection method to the terrain and buildings separate I get good intersection lines, but in the end I need only one continuous polyline for each intersection plane, so I guess to do the operation separate for terrain and buildings is no option...

@ djordje thx for the plugin, I'll test that as soon I can)

Permalink Reply by David Rutten on October 26, 2012 at 2:49pm

I tried several times today but the file download user session is always timed out or something. You can use the McNeel upload system if you want, put my email (david@mcneel.com) in the recipient box:

http://www2.mcneel.com/upload/Upload.aspx

David Rutten

david@mcneel.com

Poprad, Slovakia

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