1. A method for approximating original design intents during reverse engineering using 3D scan data, comprising: using a computer for: providing a collection of 3D scan data representing the shape of a three dimensional object, the 3D scan data combined in a plurality of meshes, the plurality of meshes combined into a mesh model representing the three dimensional object; segmenting the mesh model with a segmentation facility into a plurality of mesh regions; selecting a mesh region and a design intent, the design intent being an original design feature; calculating programmatically a value for the selected design intent for the selected mesh region, the calculating using the 3D scan data for the selected mesh region; selecting a specified feature in a CAD model formed from the mesh model; and calculating an estimated parameter value for the specified feature using an executable software process to process the 3D scan data associated with the specified feature.