The Z Depth node converts the Z-depth in camera space to a greyscale texture (figure 1).



Tool Z Depth



Figure 1: The Z-Depth node connected to the Diffuse pin on a Diffuse material and the material is applied to all the objects in the scene 


Z-Depth Parameters

Normalize Results - Takes the result and normalizes the values between 0 and 1.

Normalization Range - Determines the minimum and maximum values for the normalized range.