Small craft hull form surface definition in a high-level computer graphics design environment

The purpose of the research described has been to develop and evaluate procedures for the mathematical modeling of hull forms. This has been accomplished through the application and integration of high-level computer graphics technology into the design process. This technology is characterized by the ability to manipulate a realistically rendered image of a three-dimensional object, with a colored and shaded surface, in real time. The hull forms studied are appropriate to hard chine and round bilge small craft. The first interactive graphics program has been developed for the definition of developable hull surfaces such as the hard chine hull. Control curves, including the keel chine and sheer lines, are faired interactively through real-time graphical techniques on the workstation using the Curve Fairing Tool (CFT) program. A developable surface is then generated between the control curves using the Developable Surface Definition Tool (DSDT). B-spline mathematical techniques have been found to be particularly useful for defining complex three-dimensional sculpted surfaces, such as the round bilge hull. A second interactive graphics program, SPLINE, has been developed, which facilitates the interactive definition of the B-spline control graph and real-time manipulation of the model image. Finally, a technique has been developed for in situ measurements of an existing hull form that might serve, for example, as a "parent" for further development using either DSDT or SPLINE.