Function ray_sphere_intersect 

pub fn ray_sphere_intersect(
    origin: Vector3D,
    dir: Vector3D,
    center: Vector3D,
    radius: f64,
) -> Option<(f64, Vector3D)>

Intersects a ray with a sphere centered at center with radius radius.

Uses the standard quadratic-form ray-sphere test.

Arguments

• Vector3D - The ray origin.
• Vector3D - The ray direction (expected to be unit length).
• Vector3D - The sphere center.
• f64 - The sphere radius (must be positive).

Returns

• Option<(f64, Vector3D)> - The hit distance and surface normal, or None on miss.