A control apparatus acquires a group of images, including an image acquired by capturing an image of an object irradiated with first pattern light, an amount of the first pattern light changing periodically, in a predetermined direction, and an image acquired by capturing images of the object irradiated with second pattern light, an amount of the second pattern light changing periodically, in the predetermined direction, and having a phase difference from the first pattern light. The control apparatus also acquires one image by capturing an image of the object irradiated with third pattern light, that provides for identification of a position of at least one period, of a plurality of periods, included in one of the first pattern light and the second pattern light, and calculates a three-dimensional shape of the object based on the group of images and the one image, for each of a plurality of directions.