Moving System

《Architectural Geometry》

instantaneous rotation: normals of each path are passing through pole at time t
instantaneous translation: normals of each path are parallel

Developable Surface

Single Curved Surface
evolute: trace of curvature center 曲率中心軌跡
PQ-strip
PQ-mesh

Surface Development
transition pieces

空間中兩條線段的雙一次內插，可以製造曲線。

Pappus–Guldinus theorem
https://en.wikipedia.org/wiki/Pappus's_centroid_theorem
solid of revolution
面積＝曲線長度Ｘ線段重心移動距離(弧長)
體積＝曲線面積Ｘ面積重心移動距離(弧長)

Folding

Erdős–Nagy Theorem

一個凹多邊形不斷翻折，最後必能變成凸多邊形。

Origami

https://langorigami.com/
http://jasonku.mit.edu/
https://kusudama.me/

ICPC 3568 4640 UVa 1446

Kirigami

https://caiguijiang.github.io/publication/2020_siga_kirigami/
https://en.wikipedia.org/wiki/Kirigami