To the Graduate Council: I am submitting herewith a thesis written by ...

Chapter 3: Data Collection and Modeling 34Thompson et al. [Thompson et al., 1999] apply reverse engineering as a process that willenable the recreation of objects that are out of production.With the emergence of high speed accurate laser scanners reverse engineering is movingaway from the traditional tedious but accurate coordinate measuring machines (CMM).As discussed in the previous section, we use an active range sensor to acquire anensemble of range images to reconstruct a CAD-like model of the object. We beginreverse engineering with acquisition of range images using the IVP sensor, whichprovides speed and accuracy. We would like to summarize the process of modelcreation as a block diagram in Figure 3.5.After data acquisition we have a set of range images representing multiple view pointsaround an object. The task is now to reconstruct the CAD model from these rangeimages. The fundamental challenge in modeling the range images is that ofreconstruction as discussed in [Hoppe et al., 1992]. The challenge lies in aligningmultiple views into a global coordinate frame (also called as the process of registration)and integrating and merging aligned views into a CAD representation. As discussedearlier, multiple views of an object are necessary to overcome occlusions. As the cameramoves to the new view, the resulting data is relative to the new view position.Registration is the process where we align these multiple views and their associatedcoordinated frames into a single global coordinate frame. The registration problem isessentially recovering the rigid transformation from the new range data. We define rigidtransformation asy = Rx + t(3.7)Multi-viewRange ImagesMulti-viewRegistrationViewIntegrationMeshModelingRange Sensing Model Reconstruction CAD RepresentationPipeline for Reverse EngineeringFigure 3.5: Block diagram of a laser-based reverse engineering system.