diff --git a/src/raycasting/sphere.rs b/src/raycasting/sphere.rs
index e89d518..6effcf7 100644
--- a/src/raycasting/sphere.rs
+++ b/src/raycasting/sphere.rs
@@ -24,42 +24,6 @@ impl<T: RealField> Sphere<T> {
 
 impl<T: RealField> Intersect<T> for Sphere<T> {
     fn intersect<'a>(&'a self, ray: &Ray<T>) -> Option<IntersectionInfo<T>> {
-        /*let ray_origin_to_sphere_centre = self.centre - ray.origin;
-        let radius_squared = self.radius * self.radius;
-        let is_inside_sphere = ray_origin_to_sphere_centre.norm_squared() <= radius_squared;
-        // t0/p0 is the point on the ray that's closest to the centre of the sphere
-        // ray.direction is normalized, so it's not necessary to divide by its length.
-        let t0 = ray_origin_to_sphere_centre.dot(&ray.direction);
-        if !is_inside_sphere && t0 < T::zero() {
-            // Sphere is behind ray origin
-            return None;
-        }
-        // Squared distance between ray origin and sphere centre
-        let d0_squared = (ray_origin_to_sphere_centre).norm_squared();
-        // p0, ray.origin and sphere.centre form a right triangle, with p0 at the right corner,
-        // Squared distance petween p0 and sphere centre, using Pythagoras
-        let p0_dist_from_centre_squared = d0_squared - t0 * t0;
-        if p0_dist_from_centre_squared > radius_squared {
-            // Sphere is in front of ray but ray misses
-            return None;
-        }
-        let p0_dist_from_centre =p0_dist_from_centre_squared.sqrt();
-        // Two more right triangles are formed by p0, the sphere centre, and the two places
-        // where the ray intersects the sphere. (Or the ray may be a tangent to the sphere
-        // in which case these triangles are degenerate. Here we use Pythagoras again to find
-        .// find the distance between p0 and the two intersection points.
-        let delta = (radius_squared - p0_dist_from_centre_squared).sqrt();
-        let distance = if is_inside_sphere {
-            // radius origin is inside sphere
-            t0 + delta
-        } else {
-            t0 - delta
-        };
-        let location = ray.point_at(distance);
-        let normal = (location - self.centre).normalize();
-        let tangent = normal.cross(&Vector3::z_axis());
-        let cotangent = normal.cross(&tangent);
-        let retro = -ray.direction;*/
         let two: T = convert(2.0);
         let four: T = convert(4.0);
         let r_o = ray.origin.coords;