A method for determining a transformation between a first coordinate system of an ultrasonic haptic device and a second coordinate system of a visual sensor device. The method includes: triggering generation of an ultrasonic focal point; obtaining images depicting a body part of a user while the ultrasonic focal point is active; determining a position of the ultrasonic focal point in the second coordinate system when the body part of the user is in the ultrasonic focal point; repeating the triggering, obtaining and determining; and calculating a first transformation between the first coordinate system and the second coordinate system based on the positions of the ultrasonic focal points in the first coordinate system and the second coordinate system to thereby calibrate a relationship between the ultrasonic haptic device and the visual sensor device.