Chamfer (geometry)


In geometry, a chamfer or edge-truncation is a topological operator that modifies one polyhedron into another. It separates the faces by reducing them, and adds a new face between each two adjacent faces. Oppositely, similar to expansion, it moves the faces apart outward, and adds a new face between each two adjacent faces; but contrary to expansion, it maintains the original vertices.
For a polyhedron, this operation adds a new hexagonal face in place of each original edge.
In Conway polyhedron notation, chamfering is represented by the letter "c". A polyhedron with edges will have a chamfered form containing new vertices, new edges, and new hexagonal faces.

Platonic solids

Chamfers of five Platonic solids are described in detail below.

Relation to Goldberg polyhedra

The chamfer operation applied in series creates progressively larger polyhedra with new faces, hexagonal, replacing the edges of the current one. The chamfer operator transforms GP to GP.
A regular polyhedron, GP, creates a Goldberg polyhedra sequence: GP, GP, GP, GP, GP...
GPGPGPGPGP...
GPIV

C

cC

ccC

cccC

ccccC
...
GPV

D

cD

ccD

cccD

ccccD
...
GPVI

H

cH

ccH

cccH

ccccH
...

The truncated octahedron or truncated icosahedron, GP, creates a Goldberg sequence: GP, GP, GP, GP...
GPGPGP...
GPIV

tO

ctO

cctO
...
GPV

tI

ctI

cctI
...
GPVI


ctΔ

cctΔ
...

A truncated tetrakis hexahedron or pentakis dodecahedron, GP, creates a Goldberg sequence: GP, GP, GP...
GPGPGP...
GPIV

tkC

ctkC

cctkC
...
GPV

tkD

ctkD

cctkD
...
GPVI

tkH

ctkH

cctkH
...