From Ohm

# View-Aligned Planes

For an eye point $\vec{ e }$ and a main viewing direction $\vec{ d }$ and a step length $\Delta t$ the pivot points $\vec{ p }_i$ (i=0..n-1) of the view-aligned slicing planes orthogonal to the z-axis of the view coordinate system are:

$\vec{ p }_i = \vec{ e }+(far-i \Delta t)\vec{ d }$

The normal of the slicing planes $\vec{ n }_i$ is equal to the main viewing direction $\vec{ d }$.