Continuity Mapping for Multi-Chart Textures

It is well known that multi-chart parameterization methods introduce seams over the object being parameterized. This causes serious problems for several applications, like texture filtering and simulations in texture domain (e.g. fluid simulations). In this paper we present a set of two techniques, collectively known as ’Continuity Mapping’, that when used together make a multi-chart parameterization seamless. The first one, the ’Traveller’s Map’, which is used for solving the spatial continuity problem, and the second one ’Sewing the Seams’, addresses the resolution continuity problem. Traveller’s Map defines a correspondence between any pair of seam edges in texture space; allowing identification of any point and direction outside a chart with the corresponding point inside the other chart that shares the common seam edge in 3D. For rendered fragments placed near the seam edges, the second technique uses the first one to generate a thin border of virtual triangles in texture space, to correctly interpolate and filter texture values through seams. Continuity Mapping does not require any modification of the artist-provided textures or models, and achieves continuity with small memory and computational costs.