The parameters need to be homogeneous coordinates.
from - foot point of ray in world coordinates (x,y,z,1)
to - end point of ray in world coordinates (x,y,z,1) (can be at infinity)
Valid pick points are of the form p = a*from+b*to where a*b >= 0
That is, the affine coordinate (b/a) of p on the line with basis (from,to) is non-negative
list of PickResults sorted by distance from foot point