Coordinate systems in Stytra

Stytra follows the common convention for displaying images on screens: the x axis increases to the right and the y axis increases downward, with (0,0) being the upper right corner. For the recorded coordinates, the same holds. The angles correspondingly increase clockwise.

Calibration establishes a mapping between the camera and projector coordinate systems. The cam_to_proj and proj-to_cam matrices transform points from one coordinate system to another.

Visual stimuli are usually configured to take dimensions in millimeters, whereas the scaling factor is taken from the calibration procedure.