View difference between Paste ID: ubATCxJY and jF6SPafS

     //XYZ is a 3D vector class with components X, Y, and Z
     //Obvious thing but worth mentioning: if converting this to
     //use floats, make sure you convert all literal doubles
     //to end in f (1.0 becomes 1.0f, 0.5 becomes 0.5f, etc)
 
     //based on http://answers.unity3d.com/questions/467614/what-is-the-source-code-of-quaternionlookrotation.html
     public static Quaternion LookRotation(XYZ forward, XYZ up)
     {
         forward = forward.Normalize();
 
         XYZ vector = forward.Normalize();
         XYZ vector2 = up.CrossProduct(vector).Normalize();
         XYZ vector3 = vector.CrossProduct(vector2);
         var m00 = vector2.X;
         var m01 = vector2.Y;
         var m02 = vector2.Z;
         var m10 = vector3.X;
         var m11 = vector3.Y;
         var m12 = vector3.Z;
         var m20 = vector.X;
         var m21 = vector.Y;
         var m22 = vector.Z;
 
         double num8 = (m00 + m11) + m22;
         var quaternion = new Quaternion();
         if (num8 > 0.0)
         {
             var num = (double)Math.Sqrt(num8 + 1.0);
             quaternion.w = num * 0.5;
             num = 0.5 / num;
             quaternion.x = (m12 - m21) * num;
             quaternion.y = (m20 - m02) * num;
             quaternion.z = (m01 - m10) * num;
             return quaternion;
         }
         if ((m00 >= m11) && (m00 >= m22))
         {
             var num7 = (double)Math.Sqrt(((1.0 + m00) - m11) - m22);
             var num4 = 0.5 / num7;
             quaternion.x = 0.5 * num7;
             quaternion.y = (m01 + m10) * num4;
             quaternion.z = (m02 + m20) * num4;
             quaternion.w = (m12 - m21) * num4;
             return quaternion;
         }
         if (m11 > m22)
         {
             var num6 = (double)Math.Sqrt(((1.0 + m11) - m00) - m22);
             var num3 = 0.5 / num6;
             quaternion.x = (m10 + m01) * num3;
             quaternion.y = 0.5 * num6;
             quaternion.z = (m21 + m12) * num3;
             quaternion.w = (m20 - m02) * num3;
             return quaternion;
         }
         var num5 = (double)Math.Sqrt(((1.0 + m22) - m00) - m11);
         var num2 = 0.5 / num5;
         quaternion.x = (m20 + m02) * num2;
         quaternion.y = (m21 + m12) * num2;
         quaternion.z = 0.5 * num5;
         quaternion.w = (m01 - m10) * num2;
         return quaternion;
     }