1. A method for collecting and processing physical space data for use while performing an image-guided surgical (IGS) procedure, the method comprising: obtaining a preoperative image of a surface of a non-rigid structure of interest in a patient, wherein the preoperative image was acquired during a preoperative presentation of the structure; during an intraoperative presentation of the structure, generating in patient space, via digitization equipment of an IGS system, partial surface data extending over a portion of the surface, wherein the portion, as presented intraoperatively, is less than 50% of the surface and wherein during the intraoperative presentation the surface is deformed relative to the preoperative presentation; performing, via a processor of the IGS system, a rigid alignment, in the patient space, of the partial surface data to a computer model corresponding to the preoperative image, the computer model comprising a plurality of nodes, the plurality of nodes extending over all of the surface of the non-rigid structure; computing, via the processor of the IGS system, a deformation of the computer model, wherein the deformation provides a non-rigid alignment, in the patient space, of said computer model and the partial surface data, said deformation computed using boundary conditions calculated for each of the plurality of nodes of said computer model, said boundary conditions calculated using a kernel function and spatial difference values for each of the plurality of nodes derived from said rigid alignment; applying said deformation of the computer model to the preoperative image and thereby computing a modified image; and displaying, at a display of the IGS system, the modified image.