1. A motion compensation system for tracking and compensating for patient motion during a medical imaging scan, the motion compensation system comprising: an optical marker comprising an optically visible pattern and a mounting portion, the mounting portion configured to affix the optical marker to an object being tracked, the optically visible pattern comprising a plurality of reference point locators, each locator configured to define a single reference point of a reference shape; a first optical detector positioned to digitally image the optically visible pattern along a first line of sight, the first optical detector configured to generate a first digital image of the optically visible pattern; a second optical detector positioned to digitally image the optically visible pattern along a second line of sight, the second optical detector configured to generate a second digital image of the optically visible pattern; a tracking engine configured to determine a pose of the object in six degrees of freedom by analyzing the first and second images; and a controller interface configured to generate tracking information based on the pose and to electronically transmit the tracking information to a scanner controller to enable compensation within a medical imaging scanner for object motion, wherein each reference point is defined by a centroid of a reference point locator, and wherein the tracking engine and controller interface comprise a computer processor and an electronic storage medium.