On: Improving the fast inverse square root (2010)

[toolslive]

What they typically do in 3d gaming is update the matrix that holds the transformation by a left multiplication, every time the camera changes. So

Tn = U_{n-1} * U_{n-2} * .... * U_0 * T_0

After a while,your matrix accumulates errors, but it's easy to just start and take a fresh one.