An autonomous store system that analyzes camera images to track people and their interactions with items using a processor that obtains a 3D model of a store that contains items and item storage areas. Receives images from cameras captured over a time period and analyzes the images and the 3D model of the store to detect a person in the store based on the images, calculates a trajectory of the person, identifies an item storage area proximal to the trajectory of the person during an interaction time period, analyzes two or more images to identify an item within the item storage area that is moved during the interaction time period. The images are captured within or proximal in time to the interaction time period, and the images contain views of the item storage area, and attribute motion of the item to the person. Enables calibration and placement algorithms for cameras.