function rotationX(angle) {
  var c = Math.cos(angle);
  var s = Math.sin(angle);
  return [1, 0, 0, 0, c, s, 0, -s, c];
}
/**
 * Returns rotation matrix for x axis.
 * @public
 */
Returns rotation matrix for x axis.
@public
Returns rotation matrix for x axis . @public
function rotationX(angle) {
  var c = Math.cos(angle);
  var s = Math.sin(angle);
  return [1, 0, 0, 0, c, s, 0, -s, c];
}
function rotationX ( angle ) { var c = Math . cos ( angle ) ; var s = Math . sin ( angle ) ; return [ 1 , 0 , 0 , 0 , c , s , 0 , - s , c ] ; }
Returns rotation matrix for x axis.
Returns rotation matrix for x axis .