Also see: http://en.wikipedia.org/wiki/Fast_inverse_square_root http://en.wikipedia.org/wiki/Fast_inverse_square_root And for more analysis and improvements se

Also see: http://en.wikipedia.org/wiki/Fast_inverse_square_root http://en.wikipedia.org/wiki/Fast_inverse_square_root And for more analysis and improvements see those papers: http://www.lomont.org/Math/Papers/2003/InvSqrt.pdf http://www.lomont.org/Math/Papers/2003/InvSqrt.pdf http://www.daxia.com/bibis/upload/406Fast_Inverse_Square_Root.pdf http://www.daxia.com/bibis/upload/406Fast_Inverse_Square_Roo... http://www.geometrictools.com/Documentation/FastInverseSqrt.pdf http://www.geometrictools.com/Documentation/FastInverseSqrt....