function SphericalHarmonics3() {

	this.coefficients = [];

	for ( var i = 0; i < 9; i ++ ) {

		this.coefficients.push( new Vector3() );

	}

}
@author bhouston / http://clara.io
@author WestLangley / http://github.com/WestLangley

Primary reference:
  https://graphics.stanford.edu/papers/envmap/envmap.pdf

Secondary reference:
  https://www.ppsloan.org/publications/StupidSH36.pdf