I am looking for Python function that would compute distance from a point in 3D (x_0,y_0,z_0) to a line segment defined by its endpoints (x_1,y_1,z_1) and (x_2,y_2,z_2).
I have only found solution for 2D for this problem.
There are solutions to finding a distance from a point to a line in 3d, but not to a line segment, like here:
(picture taken from Calculate distance point to line segment with special cases)
This answer is adapted from here: Calculate the euclidian distance between an array of points to a line segment in Python without for loop.
Function lineseg_dist
returns the distance the distance from point p to line segment [a,b]. p
, a
and b
are np.arrays.
import numpy as np
def lineseg_dist(p, a, b):
# normalized tangent vector
d = np.divide(b - a, np.linalg.norm(b - a))
# signed parallel distance components
s = np.dot(a - p, d)
t = np.dot(p - b, d)
# clamped parallel distance
h = np.maximum.reduce([s, t, 0])
# perpendicular distance component
c = np.cross(p - a, d)
return np.hypot(h, np.linalg.norm(c))