Calibrating optical combiner using structured light

A system implemented in an enclosed space, the system comprising:

• at least one light source;
• at least one tracking camera;
• an optical combiner arranged on an optical path of a light field display unit and on an optical path of a real-world light field of a real-world environment;
• and
• at least one processor configured to:
• control the at least one tracking camera to capture at least one image of the enclosed space, whilst controlling the at least one light source to project at least one light pattern onto a semi-reflective surface of the optical combiner;
• detect, in the at least one image, a reflection of at least a part of the at least one light pattern off at least one surface in the enclosed space, and determine a shape of said reflection;
• determine a curvature of the optical combiner, based on a shape of at least said part of the at least one light pattern and the shape of the reflection of at least said part of the at least one light pattern;
• control the at least one tracking camera to capture a first set of reference images of the enclosed space, while controlling the at least one light source to project the at least one light pattern onto the semi-reflective surface of the optical combiner;
• extract features from the first set of reference images;
• select, from among the features extracted from the first set of reference images, a first set of features that pertain to at least one object that has the at least one surface off which at least a part of the at least one light pattern is reflected to generate a reference reflection;
• determine a first relative position of the reference reflection with respect to positions of the features of the first set;
• extract features from the at least one image of the enclosed space;
• select, from amongst the features extracted from the at least one image, a second set of features that pertain to the at least one object that has the at least one surface off which at least said part of the at least one light pattern is reflected to generate said reflection and that match with at least a subset of the first set of features;
• determine a second relative position of said reflection with respect to positions of the features of the second set;
• and
• determine a change in at least one of:
• a position, an orientation, the curvature of the optical combiner, based on a difference between the first relative position of the reference reflection and the second relative position of said reflection.