topic Re: 3D Face to Polylines Macro in Visual LISP, AutoLISP and General Customization Forum

3D Face to Polylines Macro

Anonymous — Thu, 30 Nov 2017 14:14:22 GMT

I am looking for macro which converts 3DFaces to Polylines. Do anybody have one?

Guide me, please, how to write one by myself?

Re: 3D Face to Polylines Macro

Kent1Cooper — Thu, 30 Nov 2017 14:50:29 GMT

Check out 3DFacesTo3DPolylines.lsp, with its 3DF2PL command, available here.

Re: 3D Face to Polylines Macro

Anonymous — Thu, 30 Nov 2017 15:11:40 GMT

It is perfect. Thank You very much

Re: 3D Face to Polylines Macro

john.uhden — Thu, 30 Nov 2017 15:18:06 GMT

If what @Kent1Cooper directed you to doesn't work, I have one I wrote years ago to turn a sea of 3Dfaces into 3Dlines for creating a perfect Softdesk TIN. The situation was that the vertices of 3Dfaces were treated as just random points whereas 3Dlines could be defined as breaklines. Where 3Dfaces abut one another, the program knows to provide just one 3Dline so you don't end up with a bundle of duplicates.

If you are interested in converting random 3Dfaces each to one 3D polyline, then we would have to modify the code, but it's not a huge deal.

What's wrong with the 3Dfaces? Do they have frowns?

Re: 3D Face to Polylines Macro

Kent1Cooper — Thu, 30 Nov 2017 15:39:08 GMT

@john.uhden wrote:

....

What's wrong with the 3Dfaces? Do they have frowns?

The genesis of that routine I linked to was actually the other routine that is linked to at the beginning of the description there, which converts 3Dfaces to Lines [omitting any invisible edges of the faces]. The reason for that one was a request from someone who wanted to TRIM things using the edges of 3Dfaces as trim boundaries. What was "wrong" with 3Dfaces in their case was that TRIM doesn't accept them as boundaries [nor does EXTEND], so they needed them converted into something that can be used as trim boundaries.

Re: 3D Face to Polylines Macro

john.uhden — Thu, 30 Nov 2017 18:20:26 GMT

Thanks, Kent, for the explanation.

@john.uhden asked, "What's wrong with the 3Dfaces? Do they have frowns?"

@Kent1Cooper explained, "What was "wrong" with 3Dfaces ... [is] that TRIM doesn't accept them as boundaries [nor does EXTEND]"