Function continuous_line3_sphere3 

pub fn continuous_line3_sphere3<S>(
    line: Line3<S>,
    sphere: Sphere3<S>,
) -> Option<(Line3Point<S>, Line3Point<S>)>
where
    S: OrderedField + Sqrt,

Compute the continuous intersection of a 3D line with a 3D sphere.

If the line and sphere intersect, the two intersection points are returned with the scalar parameter corresponding to that point along the line.

let sphere = Sphere3::unit();
let line = Line3::new  ([0.0, 0.0, 0.0].into(), Unit3::axis_x());
assert_eq!(
  continuous_line3_sphere3 (line, sphere).unwrap(),
  ( (-1.0, [-1.0, 0.0, 0.0].into()),
    ( 1.0, [ 1.0, 0.0, 0.0].into())
  )
);

Returns None if the line and sphere are tangent:

let sphere = Sphere3::unit();
let line   = Line3::new  ([0.0, 0.0, 1.0].into(), Unit3::axis_x());
assert_eq!(continuous_line3_sphere3 (line, sphere), None);