A medical navigation system is provided for acquiring a depth map of a surgical site of interest in a patient. The medical navigation system comprises a camera, a light projecting device, a display, and a controller. The controller has a processor coupled to a memory. The controller is configured to generate a signal provided to the light projecting device to project an edge indicator on the surgical site of interest, generate a signal to operate the camera to perform a focus sweep and capture a plurality of images during the focus sweep where the plurality of images includes the projected edge indicator, receive from the camera data representing the plurality of images captured during the focus sweep, and generate a depth map of the surgical site of interest using the data representing the plurality of images.