Function normalize

normalize(out: spherical.Spherical, a: spherical.Spherical): spherical.Spherical
Sets r=1, preserving the angles. No-op if r is already zero.
Parameters
- out: spherical.Spherical
  the receiving Spherical
- a: spherical.Spherical
  the source Spherical
Returns spherical.Spherical
out
- Defined in core/spherical.ts:82