Patterns model:

Model continued:

further explanation of the shift rule:

Following the line of the prominent black bar, as the bar meets a grey (initially red) bar the shift occurs, leaving a buck in the black bar.  And as the height of the grey bar in 3D is half the height, this shift can also be seen in elevation.

This can be explored further in order to break the bars, allowing gaps in the vertical axis to bleed the inverted (void) spaces through the field of bars.  See below:

Model inserted onto site: