w: (2, -4, 0)
P: (6, 2, 0)
u: (-8, -4, 0)
P1: P + (0.25 * u)
Q1: P - w + u
g = Line(P, P1)
a: abs(w)
Q: Q1 - (0.5 * u)
h = Line(Q1, Q)
v = Vector(P, P1)
b = Vector(Q, Q1)
X = Point(h)
H: (((x, y, z) - X) * u) = 0
F = Intersect(g, H)
f = Segment(X, F)