Extracting polygons from 3D models?

[shuttle]

I am converting 3D DXF models into real objects, and wondered if there is an easy(er) way to lay the individual polygons of a 3D model flat on the X-Y plane for output to the Shopbot.
The way I am doing it now is very time consuming.
thanks.

[rgbrown@itexas.net]

Rob,

What program are you using? I use RHINO and think it would be fairly quick in it.

Ron Brown - rgbrown@itexas.net (mailto:rgbrown@itexas.net)

If Stupidity got us into this mess,
then why can't it get us out? - Will Rogers

[shuttle]

I use trueSpace, select each polygon individually,copy it then lay it flat on the X-Y plane.
Keeping track/orientation of each piece has been a challenge. There are over 250 pieces (all triangles) in my first try.

[rgbrown@itexas.net]

Rob,

I am beginning to understand what you are doing. I know of no method other than writing 'scripts' which would automate many commands. It would still be time consuming.

Ron Brown - rgbrown@itexas.net (mailto:rgbrown@itexas.net)

If Stupidity got us into this mess,
then why can't it get us out? - Will Rogers

[bill.young]

Hi Rob,

I found a Mac program named Touch3d a while back that looks like it can take a 3d model and "unfold" it so that all the pieces are laid out flat. It's $300 or so, but they claim that it will run in Windows with an emulator.

Their web page is http://www.algonet.se/~ludesign/indexT.html. My guess is that there are probably Windows programs that do the same thing...you might search Google for something like "unfolding software".

Hope this helps,
Bill

[gerald_d]

Hi Bill, I thought that you Rhino-enabled boat designers did this type of thing quite often?


Rob essentially has the surface of a "bulbous bow" shape modelled with a mesh of triangular finite elements. He wants to cut each of these triangles individually on the SB and then stitch them together to approximately cover the bow shape. Does this make any more sense?

[bill.young]

Hi Gerald,

The neat thing about the Touch3d program is that it looks like it can take the whole model and basically mash it flat. Their web site shows it working with models of cars and cell phones and things like that. If you cut out the outline of the panels and scored along the lines where the parts were connected with a v bit, you might be able to fold things back up and keep everything registered correctly.


Rhino can do a similar thing (develop a surface), but as far as I can figure out you have to do it one surface at a time.

Bill

[billp]

Now you guys can see how tricky it must have been for cartographers to develop the Mercator projection maps before computers..

[gerald_d]

That's why the Flat Earth Society was so attractive . . . .

[rgbrown@itexas.net]

Please do not refer to the Flat Earth in past tense

[shuttle]

Bill,
Thanks for the pointer, looks like it would do the job...

[signguy]

http://www.page.sannet.ne.jp/jun_m/index-eng.html
unfolds dxf to eps
Tenkai is a shareware.
The shareware fee is US$20.
A part of its functions is unavailable until you enter password

[signguy]

http://www1.sphere.ne.jp/mizno/
metaseqoia le doesnt unfold models
but its free and has great primitives
and no support and its also japanese
some segway huh