Creating a dual polyhedron

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Simon Van de Lagemaat

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Jul 11, 2012, 4:02:27 PM7/11/12
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I'm looking to create a specif type of geodesic sphere like the one in this pic.

 

http://upload.wikimedia.org/wikipedia/commons/e/e7/G%C3%A9ode_V_3_1_duale.gif

 

Basicall as many hexagons as I can muster :-)  Anyone got some idea on ways to do this in Soft or even in a 3rd party program?

 

Cheers

Alan Fregtman

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Jul 11, 2012, 4:31:11 PM7/11/12
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It's a little ugly to import this Collada stuff, but it might be close to what you need:

Octavian Ureche

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Jul 11, 2012, 5:12:12 PM7/11/12
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you might also want to take a look at this:  http://lesterbanks.com/2010/12/creating-a-golf-ball-in-maya-using-geosphere/

cheers

Alan Fregtman

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Jul 11, 2012, 5:33:58 PM7/11/12
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Oh hey, that gave me an idea...

1. Get, Primitive->Polygon Mesh->Icosahedron
2. Play with the Geodesic Frequency slider to get the desired subdivision level. (6 for example.)
3. Tag all points, rightclick -> Bevel Components.
4. Play with Bevel Distance. Looks decent at 0.85 here.

Inline image 1

Fun! :D
icosahedron_point_beveling.png

Ben Rogall

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Jul 11, 2012, 5:43:50 PM7/11/12
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Very nice! I recently had to solve a similar problem but I didn't notice that option. I just needed the vertices, so I started with the basic Icosahedron primitive and then did Loop subdivision on it, which I think gave the dual polyhedron to this, like in the Sketchup link you gave earlier.

Ben

Simon Van de Lagemaat

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Jul 11, 2012, 5:51:10 PM7/11/12
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Agh! Perfect... the irony is that I had tried a similar approach in Modo but the results weren't as even as yours.  I also didn't see that frequency option before when I was puttering through the primitives.

 

Thanks Allen!

David Barosin

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Jul 11, 2012, 5:56:27 PM7/11/12
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Alan that is very cool.  I just tried an extreme bevel value of 3 and then did a filter points.  It gets that nice pentagon with even hexes around it. 
image001.png

Amaan Akram

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Jul 11, 2012, 6:03:41 PM7/11/12
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Alan, very cool indeed!
--
3D Artist/TD @ The Mill, London
image001.png

Simon Van de Lagemaat

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Jul 11, 2012, 6:54:15 PM7/11/12
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Bonus tip!!!

 

Run a smooth or relax op after the bevel and watch your gimpy edge lengths even out!  The pentagons will shrink slightly but the tradeoff produces a much more even mesh.

Alan Fregtman

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Jul 11, 2012, 8:29:33 PM7/11/12
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You guys should try extruding while selecting all edges. Cool flowery/snowflakey patterns appear. :)
image001.png

Alan Fregtman

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Jul 11, 2012, 10:17:30 PM7/11/12
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Playing around with combinations of selecting adjacent components then extruding or beveling...

Inline image 1

I started annotating the steps but it got too annoying after the third one so I gave up, but here's an emdl download for anyone interested:
(It's all just variations of extruding either points or all edges, then selecting adjacent components, inverting selection sometimes, extruding again with Merge off, etc.)
image001.png
icosahedron_topo_experiments[1].png

Ed Manning

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Jul 11, 2012, 10:33:26 PM7/11/12
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did a golf ball a few years back just this way!
image001.png
icosahedron_topo_experiments[1].png

Chris Chia

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Jul 12, 2012, 5:29:00 AM7/12/12
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Try driving the extrusion by ICE :D


From: softimag...@listproc.autodesk.com [mailto:softimag...@listproc.autodesk.com] On Behalf Of Alan Fregtman
Sent: Thursday, July 12, 2012 10:18 AM
To: soft...@listproc.autodesk.com
Subject: Re: Creating a dual polyhedron

Playing around with combinations of selecting adjacent components then extruding or beveling...

[Inline image 1]

I started annotating the steps but it got too annoying after the third one so I gave up, but here's an emdl download for anyone interested:
http://s3.darkvertex.com/hlinked/4forums/icosahedron_experiments.zip
(It's all just variations of extruding either points or all edges, then selecting adjacent components, inverting selection sometimes, extruding again with Merge off, etc.)

On Wed, Jul 11, 2012 at 8:29 PM, Alan Fregtman <alan.f...@gmail.com<mailto:alan.f...@gmail.com>> wrote:
You guys should try extruding while selecting all edges. Cool flowery/snowflakey patterns appear. :)

On Wed, Jul 11, 2012 at 6:54 PM, Simon Van de Lagemaat <si...@theembassyvfx.com<mailto:si...@theembassyvfx.com>> wrote:
Bonus tip!!!

Run a smooth or relax op after the bevel and watch your gimpy edge lengths even out! The pentagons will shrink slightly but the tradeoff produces a much more even mesh.

From: softimag...@listproc.autodesk.com<mailto:softimag...@listproc.autodesk.com> [mailto:softimag...@listproc.autodesk.com<mailto:softimag...@listproc.autodesk.com>] On Behalf Of Amaan Akram
Sent: July-11-12 3:04 PM

To: soft...@listproc.autodesk.com<mailto:soft...@listproc.autodesk.com>
Subject: Re: Creating a dual polyhedron

Alan, very cool indeed!
On 11 July 2012 22:56, David Barosin <dbar...@gmail.com<mailto:dbar...@gmail.com>> wrote:
Alan that is very cool. I just tried an extreme bevel value of 3 and then did a filter points. It gets that nice pentagon with even hexes around it.

On Wed, Jul 11, 2012 at 5:51 PM, Simon Van de Lagemaat <si...@theembassyvfx.com<mailto:si...@theembassyvfx.com>> wrote:
Agh! Perfect... the irony is that I had tried a similar approach in Modo but the results weren't as even as yours. I also didn't see that frequency option before when I was puttering through the primitives.

Thanks Allen!

From: softimag...@listproc.autodesk.com<mailto:softimag...@listproc.autodesk.com> [mailto:softimag...@listproc.autodesk.com<mailto:softimag...@listproc.autodesk.com>] On Behalf Of Alan Fregtman
Sent: July-11-12 2:34 PM
To: soft...@listproc.autodesk.com<mailto:soft...@listproc.autodesk.com>
Subject: Re: Creating a dual polyhedron

Oh hey, that gave me an idea...

1. Get, Primitive->Polygon Mesh->Icosahedron
2. Play with the Geodesic Frequency slider to get the desired subdivision level. (6 for example.)
3. Tag all points, rightclick -> Bevel Components.
4. Play with Bevel Distance. Looks decent at 0.85 here.

[Inline image 1]

Fun! :D
image002.png
image003.png

Alan Fregtman

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Jul 12, 2012, 9:59:59 AM7/12/12
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Sure would be nice to have a factory Bevel compound/node for ICE
modeling.... *whistles nonchalantly* :)

Chris Chia

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Jul 12, 2012, 12:13:36 PM7/12/12
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There's already an ice "extrude" node in the topology category.
All u need is to get a "get poly index" node and pass this as an array for the extrude node ;)

Chris
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Simon Van de Lagemaat

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Jul 12, 2012, 1:00:10 PM7/12/12
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Ya I plan on putting this into ICE, learn a little about the modelling tools in there. AFAIK it shouldn't be too difficult as all the tools are there, not sure about a smooth or relax tool though.

I'll post any hassles I find here ;-)

Alan Fregtman

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Jul 12, 2012, 1:13:49 PM7/12/12
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There's been a factory Smooth compound for a couple versions now.

Simon Van de Lagemaat

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Jul 12, 2012, 1:41:52 PM7/12/12
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Well I'm already hitting some errors. On a simple icosahedron I'm using two nodes, apply disconnect component (poly, iselement) and apply extrude polygon along axis (also iselement) and all my polygons are just being scaled to 0... 2012 sap.

According to the videos I've watched this should work fine.

Also, is there a way to bevel vertices in ICE?

Chris Chia

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Jul 12, 2012, 8:32:23 PM7/12/12
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Try passing in as string or int array ;)
It works for me beautifully.

Chris
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