PROCESS FOR CREATING A PARAMETRIC SURFACE HAVING A REQUIRED GEOMETRICAL CONTINUITY

摘要

The invention is directed to a process for creating a parametric surface having a required geometrical continuity Gi, from a set of parametric elementary surfaces. Said process comprises a step of providing a set of parametric elementary surfaces, each elementary surface having edges, with vertices joining adjacent edges, each elementary surface having an internal continuity Cj at least equal to the required continuity Gi, the geometrical continuity between at least two elementary surfaces, across their common edge, being less than the required continuity Gi. Further, for each singular vertex, the process comprise steps of: defining a system of equations linking the parameters (including position coordinates of the usually called "control points") of the parametric elementary surfaces across ail edges joined to the vertex and enforcing the: required geometrical continuity across the joined edges; and solving the system of equations to obtain the parameters. Said singular vertex joins at least one edge across which the continuity between adjacent elementary surfaces is less than the required continuity Gi.