flat-unit-dodekexcavated-rhombicosidodecahedron : 無料・フリー素材/写真
flat-unit-dodekexcavated-rhombicosidodecahedron / Ardonik
| ライセンス | クリエイティブ・コモンズ 表示-継承 2.1 |
|---|---|
| 説明 | While we did not shy away from pentagon-bearing polyhedra in selecting our sample models this year, we did avoid using regular pentagon units. Yes, one does exist! Curious readers can find the Regular-pentagonal Flat Unit on page 218 of Kunihiko Kasahara's Origami Omnibus. I found that unit to be incredibly difficult to fold correctly--so much so that we actually found it easier to approximate pentagonal faces with five triangle units than to use the real thing. And since symmetric polyhedra with dodecahedral symmetry tended to have sets of 12 pentagons apiece, that meant folding sixty triangles and 60 extra joining tabs where a mere twelve sheets of paper might have otherwise been adequate was par for the course.This particular polyhedron was no different. Following existing conventions from the Cundy Deltahedra page, I call it a dodekexcavated rhombicosidodecahedron. (I wonder about that strange spelling. Why use "K" instead of "C"? If it is because of the awkwardness of the dec-ex-ca string of syllables, replacing the "C" with a "K" does not improve this...) It has 30 squares and 12 * 5 + 20 = 80 triangles.The polyhedron took about a couple of days to fold. A lot of my time during assembly was spent waiting for gobs of glue to set inside the pockets of these modules, as this foil-like holographic paper glues together poorly when one uses the small amounts of glue that one would use on normal origami paper. The paper is also expensive and difficult to take good photographs of; natural lighting seems to work best.Unlike the last two objects, this one is still with us, so it can be used as an educational prop for a class that we will be holding later in the year. |
| 撮影日 | 2010-04-02 16:31:40 |
| 撮影者 | Ardonik |
| タグ | |
| 撮影地 | |
| カメラ | Canon PowerShot A470 , Canon |
| 露出 | 0.017 sec (1/60) |
| 開放F値 | f/3.0 |
| 焦点距離 | 13714.28571 dpi |