1. A method for performing 3D CAD part body modeling using 3D scan data, comprising: providing a collection of 3D scan data representing the shape of a three dimensional object, the 3D scan data forming a model representing the three dimensional object; providing a CAD system being used to remodel at least one CAD part body; segmenting the model into a plurality of regions; receiving a selection of data from at least one of the plurality of regions, the selected data used to programmatically imply a surface body representing the region, the implied surface body used as an input argument to a CAD part body modeling operation; performing the CAD part body modeling operation using the implied surface body; receiving a selection of the modifying of the 3D scan data, the modifying altering the 3D scan data geometrically or topologically; automatically modifying the implied surface body based on the modifying of the 3D scan data; and performing the CAD part body modeling operation using the modified implied surface body as an input argument.