A method for facilitating a medical or surgical procedure in an operating site in a body of a patient may involve: displaying a first point on a first two-dimensional image of the operating site into which an elongate, flexible catheter device is inserted in response to a first user input mapping the first point on at least a second two-dimensional image of the operating site, the second two-dimensional image being oriented at a non-zero angle with respect to the first two-dimensional image displaying a first line on the second image that projects from the first point displaying a second point on the second image in response to a second user input and determining a three-dimensional location within the operating site, based on the first line and the second point on the second image.
