Does calculating Sqrt(x) as x * InvSqrt(x) make any sense in the Doom 3 BFG code?

I can see two reasons for doing it this way: firstly, the "fast invSqrt" method (really Newton Raphson) is now the method used in a lot of hardware, so this approach leaves open the possibility of taking advantage of such hardware (and doing potentially four or more such operations at once). This article discusses it a little bit.

As far as I know, the InvSqrt is used to compute colors in the sense that color depends on the angle from which light bounces off a surface, which gives you some function using the inverse of the square root.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.