Compound 5-Small inverted retro-snub icosicosdodecahedra

Show us your models and discuss model-making techniques. Paper? Wood? Single vs double tabs? etc.
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indigotwilight
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Compound 5-Small inverted retro-snub icosicosdodecahedra

Post by indigotwilight » Mon Apr 04, 2011 9:40 pm

My first day of experimenting with the full version of stella4d.
After following the tutorials, I thought I'd have a go at creating some compounds of my own using the techniques described.

Here's a compound of 5 small inverted retrosnub icosicosidodecahedra (5-SIRIID). I made it by first loading up the SIRIID, and adding to memory (slot 1).

Then I loaded up a dodecahedron, set the minimum edge length to 1.5, and changed the colour to something not in the previous SIRIID. (the edge length seems to change the relative size of the dodecahedon to SIRIID.)

Do add/blend from memory to load up the previously stored SIRIID.

ctrl+shift - right click to split the model and reveal the pentagons of the dodecahedron inside (as described in the youtube tutorial)

select a pentagon, ctrl+shift+right click to close. Store in memory slot 3.


Next, load up the compound of 5 dodecahedra, and augment using the SIRIID-dodecahedron compound stored in memory slot 3. The settings in the augmentation window are the same as those given in the tutorial.

Accept and zoom out to see the completed polyhedron compound.



Here's a render of what it looks like.

Image

Twi

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robertw
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Post by robertw » Thu Apr 07, 2011 1:22 pm

Nice. Will you be making one from paper? :wink:

indigotwilight
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Post by indigotwilight » Thu Apr 07, 2011 2:10 pm

robertw wrote:Nice. Will you be making one from paper? :wink:

If only I could, but I fear it would take too long and seriously test my patience to the limit.
I printed the net to pdf (using cutePDF) to have a look. There's so many tiny parts to it.
One of my goals though is to build a small inverted retro snub icosicosidodecahedon. The shortest edge length is still too small for any model that'll fit in a glass cabinet.

Perhaps Stella could have a 'simplify model' function? Many of those tiny parts would barely be noticed if they were removed. (The compound of 5 SIRIID had a shortest edge length of 0.4 microns!). Perhaps the simplify model could be interfaced as a user input value to 'delete all edges less than x'. Stella4d would then interpolate over those regions to close the surface and produce a simplified version of the model.

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robertw
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Post by robertw » Thu Apr 07, 2011 2:47 pm

Well I wasn't serious about making it. I certainly wouldn't try!

You can simplify models yourself with stellation mode to remove small chunks that make things difficult.

I think maybe less than ten accurate models of the small inverted retro snub icosicosidodecahedron have ever been made. Even Fr. Magnus Wenninger used nets with a small mistake in them, that missed the smallest parts. I think the models that have been made have been at least a metre wide. At that size, the smallest part is just over 3mm, which isn't too bad.

indigotwilight
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Post by indigotwilight » Fri Apr 15, 2011 1:23 pm

Thanks.. I'll give it a go. :D

Interesting you mention Magnus Wenninger. I remember finding an old copy of his book, Polyhedron Models, in the school library when I was a kid. When I browsed through it, I saw all these different stars I could make - so took it out to try and build some.
The first polyhedron I made was a dodecahedron, and then an icosidodecahedron. After that, I attempted a number of stellations of the icosahedron - carefully tracing the nets from the book using greaseproof paper from the kitchen, which I then transferred onto thin card. Or (with the simpler facets) drew them by hand using a protractor and ruler.

I wanted to make a SIRIID back then.
It is now on the list of things to do.

A 3mm edge length is definitely doable.

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