Line-Plane collision in 3D, Python 2 or 3

line-plane-collision.py

#Line-plane intersection
#By Tim Sheerman-Chase
#This software may be reused under the CC0 license

#Based on http://geomalgorithms.com/a05-_intersect-1.html
from __future__ import print_function
import numpy as np

def LinePlaneCollision(planeNormal, planePoint, rayDirection, rayPoint, epsilon=1e-6):

	ndotu = planeNormal.dot(rayDirection)
	if abs(ndotu) < epsilon:
		raise RuntimeError("no intersection or line is within plane")

	w = rayPoint - planePoint
	si = -planeNormal.dot(w) / ndotu
	Psi = w + si * rayDirection + planePoint
	return Psi


if __name__=="__main__":
	#Define plane
	planeNormal = np.array([0, 0, 1])
	planePoint = np.array([0, 0, 5]) #Any point on the plane

	#Define ray
	rayDirection = np.array([0, -1, -1])
	rayPoint = np.array([0, 0, 10]) #Any point along the ray

	Psi = LinePlaneCollision(planeNormal, planePoint, rayDirection, rayPoint)
	print ("intersection at", Psi)

That looks great! Thank you for sharing!