Most robust way to get Velocity in some particular direction

I this the most robust way to get Velocity in some particular direction Vector3.Scale(rigidBody.velocity, normalizedDirVec3).magnitude ??

just do this

//or just do rb.velocity if your object owns the rigidbody
Vector3 ObjectWorldVel = rigidBody.GetPointVelocity(Object.position);

//Object direction can be any direction faster is to just transform.direction. Example :transform.up
Vector3 objectDirection = new Vector3(0, 0, 1)
float velSpeed_Direction = Vector3.Dot(objectDirection, ObjectWorldVel);