polytope-closest-point
Computes the closest point to a polytope in arbitrary dimensions
npm install polytope-closest-point
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Version | 0.0.0 last updated a year ago |
License | BOOST |
Keywords | polytope, geometry, closest, point, triangle, line, segment, polygon, polyhedra, convex, math, 3d |
Repository | git://github.com/mikolalysenko/polytope-closest-point.git (git) |
Dependencies | numeric |
Dependents | mikolalysenko-hoarders, spatial-grid |
polytope-closest-point
Computes the closest point in a convex polytope to a given point.
Install
Using npm, type the following command into your shell:
npm install polytope-closest-point
Usage
Here is an example of how to find the closest point to a triangle in a mesh:
var mesh = require("bunny");
var result = new Array(3);
var sqr_distance = require("polytope-closest-point")(
mesh.cells[0],
mesh.positions,
[0,0,0],
result);
Which computes the closest point in the first facet of the mesh to the point [0,0,0]
, storing the resulting point in result
and the squared distance in sqr_distance
.
For more examples, see test/simple.js.
require("polytope-closest-point")(cell, positions, x[, result])
Computes the closest point in a polytope to x
, storing the result in result
.
cell
is a list of indices into a positions representing the vertices of the polytope.positions
is an array of tuples representing the vertices of the polytopex
is the point we are querying againstresult
(optional) is the array to store the closest point in.
Returns a float representing the squared Euclidean distance from x to the polytope. If no such point can be found, it returns Number.NaN
Notes: For polytopes with fewer than 4 vertices, the code uses hand optimized routines derived from WildMagick. For higher dimensions, it falls back to a general purpose quadratic programming solver that is ported from somewhat slower R/FORTRAN codes. If you are planning on using this code to do distance queries on meshed surfaces, it is recommend you triangulate all your polygons first.
Credits
Triangle/tetrahedra closest point code derived from WildMagick (c) David Eberly 1998-2012.
Other dimensions, (c) 2013 Mikola Lysenko
BOOST License.