Generalized motorcycle graphs for imperfect quad-dominant meshes

Abstract

We introduce a practical pipeline to create UV T-layouts for real-world quad dominant semi-regular meshes. Our algorithm creates large rectangular patches by relaxing the notion of motorcycle graphs and making it insensitive to local irregularities in the mesh structure such as non-quad elements, redundant irregular vertices, T-junctions, and others. Each surface patch, which can contain multiple singularities and/or polygonal elements, is mapped to an axis-aligned rectangle, leading to a simple and efficient UV layout, which is ideal for texture mapping (allowing for mipmapping and artifact-free bilinear interpolation). We demonstrate that our algorithm is an ideal solution for both recent semi-regular, quad-dominant meshing methods, and for the low-poly meshes typically used in games and movies.

Reliable feature-line driven quad-remeshing

“…In this class of methods, a layout of patches is first constructed over the surface, either to serve as a domain for a globally smooth parametrization, or to tessellate each patch in the final mesh. In the former case, the final quad-mesh is then constructed by tracing isolines of the parametrization ( [Kälberer et al 2007;Ray et al 2006;Schertler et al 2018]).…”

“…For this reasons, many methods allow for T-junctions in their definition (e.g. [Myles et al 2014;Myles and Zorin 2013;Schertler et al 2018;Usai et al 2016], among others). This eases the construction, providing more degrees of freedom, which can be exploited to optimize the domain in other respects, however this requires the solution of a non-trivial problem to produce a conforming final-mesh and to determine a globally consistent subdivision of the sides of the layout.…”

“…The conditions in Equation 1 can be understood as a generalization to non-rectangular patches of the well-known condition, sought in many coarse-layout based remeshing approaches, to attain opposite sizes of rectangular patches of a matching length ( [Campen et al 2012;Pietroni et al 2015;Schertler et al 2018;], among others).…”

Reliable feature-line driven quad-remeshing

“…In this class of methods, a layout of patches is first constructed over the surface, either to serve as a domain for a globally smooth parametrization, or to tessellate each patch in the final mesh. In the former case, the final quad-mesh is then constructed by tracing isolines of the parametrization ( [Kälberer et al 2007;Ray et al 2006;Schertler et al 2018]).…”

Rethinking Texture Mapping

“…This preserves seam invisibility, as long as the texel values on the longer side are linear interpolations of the values on the shorter side. This observation is exploited for generating uv layouts with motorcycle graphs [SPGT18]. Second, oblique placement of seams in the 2D texture space is allowed.…”