intersection line of two planes

gistfile1.txt

to determine the intersection line of two planes

planes A, B given by R^4 vectors, so that A*x = 0 if x on A, x homogeneous in R^4.

det( A, B, *, * ) is the solution space of all intersection vectors in R^4.

det( A, B, (0 0 0 1), * ) is the solution space of the direction vector d. extract it by pulling it into a R^4 vector d = (* 0).

det( A, B, *, d ) is the solution space of a point on the line. extract it by pulling it into a R^4 vector s.

intersection line = s + t*d.