extrude-by-path

extrude a 2d shape along a 3d path to build a [simplicial complex][1]

[1]: https://npmjs.com/package/simplicial-complex

example

This demo extrudes a star polygon along a helix path, twisting eight times per
revolution of the helix.

https://substack.neocities.org/extrude-helix.html

`` js
var extrude = require('extrude-by-path')
var helix = []
for (var i = 0; i < 1000; i++) {
var theta = i/3202Math.PI, d = (i-500)/250
helix.push([Math.cos(theta),Math.sin(theta),d,theta*8])
}
var mesh = extrude({
positions: [[0,0],[-0.06,-0.08],[0.06,-0.08],[0,-0.2],[0.06,-0.08],
[0.1,0.03],[0.19,-0.06],[0.1,0.03],[0,0.1],[0.12,0.16],[0,0.1],
[-0.1,0.03],[-0.12,0.16],[-0.1,0.03],[-0.06,-0.08],[-0.19,-0.06]],
cells: [[1,3,2],[0,1,2],[4,6,5],[0,4,5],[7,9,8],[0,7,8],[10,12,11],
[0,10,11],[13,15,14],[0,13,14]],
edges: [[0,1],[0,2],[0,4],[0,5],[0,7],[0,8],[0,10],[0,11],[0,13],[0,14],
[1,2],[1,3],[2,3],[4,5],[4,6],[5,6],[7,8],[7,9],[8,9],[10,11],[10,12],
[11,12],[13,14],[13,15],[14,15]],
path: helix
})
console.log(JSON.stringify(mesh))
`

api

` js
var extrude = require('extrude-by-path')
`

var mesh = extrude(opts)

* opts.positions - array of [x,y] points in the polygon
* opts.edges - array of [i,j] indices of positions
* opts.cells - array of [i,j,k] indices of positions (required for capping)
* opts.path - array of [x,y,z] or [x,y,z,twist] points. twist in radians.
* opts.closed - set to true if the path is a closed loop
* opts.startCap - set to false to skip the start cap
* opts.endCap - set to false to skip the end cap
* opts.caps - set to false to skip all caps

install

`
npm install extrude-by-path
``

license

BSD