Thickening Freeform Surfaces for Solid Fabrication

Purpose: Given an intersection-free mesh surface S , we introduce a method to thicken S into a solid H located at one side of S . By such a surface-to-solid conversion operation, industrial users are able to fabricate a designed (or reconstructed) surface by rapid prototyping. Design/methodology/approach: In this paper, we first investigate an implicit representation of the thickened solid H according to an extension of signed distance function. After that, a partial surface reconstruction algorithm is proposed to generate the boundary surface ∂H of H, which remains the given surface S on the resultant surface. Finding: Experimental tests show that the thickening results generated by our method give nearly uniform thickness and meanwhile do not present shape approximation error at the region of input surface S . These two good properties are important to the industrial applications of solid fabrication. Research limitation/implications: The input polygonal model is assumed to be intersection-free, where models containing self-intersection will lead to invalid thickening results. Originality/value: A novel robust operation to convert a freeform open surface into a solid by introducing no shape approximation error. A new implicit function that gives a compact mathematical representation, which can easily handle the topological change on the thickened solids. A new polygonization algorithm that generates faces for the boundary of thickened solid meanwhile retaining faces on the input open mesh.