System and methods for updating patient registration during surface trace acquisition

A method of dynamically updating a registration real time during a surface trace acquisition, comprising:

• selecting a registration technique from a plurality of registration techniques, wherein the plurality of registration techniques comprises a touchpoint fiducial registration technique and a surface trace registration technique;
• if the surface trace registration technique is selected,
• collecting initial feature points;
• performing a surface extraction;
• collecting initial points;
• computing an initial registration by applying a non-linear template-matching technique, thereby providing an initial registration;
• updating registration by iteratively collecting points;
• and
• registering all points, thereby providing an updated registration;
• if the touchpoint fiducial registration technique is selected,
• touching and registering a plurality of fiducial points and
• if not sufficiently accurate, repeating touching and registering a plurality of fiducial points, and
• if further accuracy is desired, performing a surface extraction and reviewing the registration;
• and
• if the registration is determined accurate within a predetermined range, accepting the registration.