Plane-plane intersection in python

Question

I need to calculate intersection of two planes in form of AX+BY+CZ+D=0 and get a line in form of two (x,y,z) points. I know how to do the math, but I want to avoid inventing a bicycle and use something effective and tested. Is there any library which already implements this? Tried to search opencv and google, but with no success.

Answer 1

Finally I've reused sympy library, by converting Ax+By+Cz+D=0 equation to (n,pt) formulation:

def planeCoeffToPoint(n,d):
    nabs = [abs(i) for i in n]
    i=nabs.index(max(nabs))
    r=[0,0,0]
    r[i]=-d/n[i]
    return r

import sympy as sp
n1=(A1,B1,C1)
D1=...
n2=(A2,B2,C2)
D2=...
pt1=planeCoeffToPoint(n1,D1)
pt2=planeCoeffToPoint(n2,D2)
pl1 = sp.Plane(pt1, normal_vector=n1)
pl2 = sp.Plane(pt2, normal_vector=n2)
r=pl1.intersection(pl2)
rp1=r[0].points[0]
rp2=r[0].points[1]
[float(rp1[0]), float(rp1[1]), float(rp1[2])] # first point on line
[float(rp2[0]), float(rp2[1]), float(rp2[2])] # second point on line

You have to call float() explicitly, becuse sympy might return Zero or Rational object, representing float.