Function cross

webgl/js/three.min.js:22934–22938

( a, b )

		// Adapted from http://www.paulbrunt.co.uk/lab/heightnormal/

		var cross = function ( a, b ) {

			return [ a[ 1 ] * b[ 2 ] - a[ 2 ] * b[ 1 ], a[ 2 ] * b[ 0 ] - a[ 0 ] * b[ 2 ], a[ 0 ] * b[ 1 ] - a[ 1 ] * b[ 0 ] ];

		}

		var subtract = function ( a, b ) {