pc1 are child objects
pc2 are parent objects

DISTANCES AS CENTROID-CENTROID.  Closest surface will be 1px less

pc1 ID25
	- related to pc2 ID89, 4px (0.8um)
	- NOT closest to pc2 ID12 (vertically above, but further during cal)
	
pc1 ID43
	- inside pc2 ID65
	- closest to top surface, -1px (-1.0um)
	- NOT closest to front surface, -8px (-1.6 um)
	
pc1 ID20
	- outside pc2 ID65
	- closest to front surface, 2px (0.4um)