Thursday, February 9, 2012

Girih Icosidodecahedron and Pentagonal Orthobirotunda

These two girih polyhedra are a 32-faced icosidodecahedron and the related pentagonal orthobirotunda. They each include 12 pentagon and 20 triangle faces. The pentagons are decorated with the girih tile pattern. A similar pattern continues across the equilateral triangles.

Icosidodecahedron Wireframe Girih Pattern

Icosidodecahedron with Girih Pattern

Icosidodecahedron

Pentagonal Orthobirotunda Wireframe Girih Pattern

Pentagonal Orthobirotunda with Girih Pattern

Pentagonal Orthobirotunda

Monday, February 6, 2012

Chalice: Concave Girih Polyhedra with Decagons and Pentagons

These girih polyhedra are 32-faced, tricontadihedra. They include 2 decagon and 10 pentagon faces, as well as triangles. The decagon and pentagon are decorated with the girih tile pattern. A similar pattern continues across the triangles. The triangles are equilateral.

These polyhedra are related to an icosidodecahedron and pentagonal orthobirotunda. You can split an icosidodecahedron in half (making two pentagonal rotunda) and reattached the halves at pentagons to create the chalice.

Chalice Wireframe Girih Pattern

Saturday, February 4, 2012

Girih Polyhedra with Decagons and Elongated Hexagons

These girih polyhedra are 32-faced, tricontadihedra. They're related to the quasiregular polyhedron, the icosidodecahedron. They include 2 decagon and 10 elongated hexagon faces, as well as triangles. The decagon and elongated hexagon are decorated with the girih tile pattern. A similar pattern continues across the triangles.

 Tricontadihedra with Girih Pattern

 Tricontadihedra

 Tricontadihedra Wireframe Girih Pattern

Saturday, January 21, 2012

Girih Polyhedra with Bow Tie Hexagon

These girih polyhedra are heptakaidecahedrons, but they include bow tie concave hexagons where my first version had elongated hexagons, and the second version had rhombi. The pentagon and elongated hexagon are decorated with the girih tile pattern. A similar pattern continues across the triangles.

 Heptakaidecahedron with Girih Pattern

 Heptakaidecahedron

 Heptakaidecahedron Wireframe Girih Pattern

Thursday, January 19, 2012

Girih Polyhedra with Rhombus

These girih polyhedra are heptakaidecahedrons, but they include rhombi where my first version had elongated hexagons. The pentagon and rhombus are decorated with the girih tile pattern. A similar pattern continues across the triangles.

Heptakaidecahedron with Girih Pattern

Heptakaidecahedron

Heptakaidecahedron Wireframe Girih Pattern

Wednesday, January 18, 2012

Girih Polyhedra Pattern

This pattern is from twenty heptakaidecahedrons decorated with girih tile strapwork, and aligned side-by-side. The heptakaidecahedron is a seventeen sided, geometric solid with two girih tile pentagonal faces, five girih tile elongated hexagon faces, and ten isosceles triangles. In this pattern, the three dimensional solids are in five rows of four each heptakaidecahedrons with each alternating row rotated by 180 degrees, and viewed in perspective.

These are the same heptakaidecahedrons at a different scale, and rotating.

Saturday, January 14, 2012

Girih Polyhedra

These images are stills from an animation of rotating girih polyhedra. The two polyhedra shown here are a dodecahedron and a heptakaidecahedron. Both of these include faces that are from the girih tile set. The heptakaidecahedron is a seventeen sided geometric solid with two girih tile pentagonal faces, five girih tile elongated hexagon faces, and ten isosceles triangles. The triangles are not original girih tiles. The dodecahedron is a platonic solid, with twelve sides of regular pentagons. The girih tile faces can be decorated with girih lines to create a three dimensional girih pattern.

In one important sense applying girih patterns to polyhedra defeats the purpose of the girih pattern system. That is, girih tiles are designed so that the interior decoration lines continue across boundaries, tangentially. When the lines cross boundaries that are not in the same plane, the continuity is interrupted.

Dodecahedron with Girih Pattern

Dodecahedron

Dodecahedron Wireframe Girih Pattern

Heptakaidecahedron with Girih Pattern

Heptakaidecahedron

Heptakaidecahedron Wireframe Girih Pattern