Free-form surface solutions can be divided into the following categories:
Feature recognition methods based on boundary matching: This method recognizes features by comparing the boundary of the free-form surface with the boundary of a known shape.
Feature recognition methods based on stereo decomposition: This method decomposes the free-form surface into multiple small parts and then performs feature recognition on each part1.
Application of free-form surfaces in AR glasses:
In the optical display solution of AR glasses, the free-form surface solution uses a free-form surface reflector with a certain reflection/transmission value. A free-form surface is a complex, unconventional surface shape with a relatively complex mathematical expression and usually does not have rotational symmetry. The light emitted by the display is directed to the concave mirror/synthesizer and reflected back into the eye. Ideally, the display source should be located directly above the eye, but in actual design it is usually moved "off-axis" and set above the forehead. Due to the distortion of the off-axis display on the concave mirror, correction is required on the software/display side