A point's [link:https://en.wikipedia.org/wiki/Spherical_coordinate_system spherical coordinates].
[page:Float radius] - the radius, or the
[link:https://en.wikipedia.org/wiki/Euclidean_distance Euclidean distance]
(straight-line distance) from the point to the origin. Default is
`1.0`.
[page:Float phi] - polar angle in radians from the y (up) axis. Default is
`0`.
[page:Float theta] - equator angle in radians around the y (up) axis.
Default is `0`.
The poles (phi) are at the positive and negative y axis. The equator
(theta) starts at positive z.
Returns a new spherical with the same [page:.radius radius], [page:.phi phi] and [page:.theta theta] properties as this one.
Copies the values of the passed Spherical's [page:.radius radius], [page:.phi phi] and [page:.theta theta] properties to this spherical.
Restricts the polar angle [page:.phi phi] to be between 0.000001 and pi - 0.000001.
Sets values of this spherical's [page:.radius radius], [page:.phi phi] and [page:.theta theta] properties.
Sets values of this spherical's [page:.radius radius], [page:.phi phi] and [page:.theta theta] properties from the [page:Vector3 Vector3].
Sets values of this spherical's [page:.radius radius], [page:.phi phi] and [page:.theta theta] properties from Cartesian coordinates.
[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]